( PDF ) Características físico-químicas de cultivares de feijão (Phaseolus vulgaris L.), e efeitos biológicos da fração fibra solúvel

Download PDF

ads:

UNIVERSIDADE

FEDERAL DE SANTA MARIA

CENTRO

DE CIÊNCIAS NATURAIS E EXATAS

PROGRAMA

DE PÓS-GRADUAÇÃO EM BIOQUÍMICA

TOXICOLÓGICA

CARACTERÍSTICAS FÍSICO-QUÍMICAS

DE CULTIVARES DE FEIJÃO (Phaseolus vulgaris L.),

E EFEITOS BIOLÓGICOS DA FRAÇÃO

FIBRA SOLÚVEL

DISSERTAÇÃO DE MESTRADO

Ivo Roberto Dorneles Prolla

Santa Maria, RS, Brasil

2006

ads:

Livros Grátis

http://www.livrosgratis.com.br

Milhares de livros grátis para download.

CARACTERÍSTICAS FÍSICO-QUÍMICAS

DE CULTIVARES DE FEIJÃO (Phaseolus vulgaris L.),

E EFEITOS BIOLÓGICOS DA FRAÇÃO FIBRA SOLÚVEL

por

Ivo Roberto Dorneles Prolla

Dissertação apresentada ao Curso de Mestrado

do Programa de Pós-Graduação em Bioquímica Toxicológica,

da Universidade Federal de Santa Maria (UFSM, RS),

como requisito parcial para obtenção do grau de

Mestre em Bioquímica Toxicológica.

Orientador: Profa. Dra. Tatiana Emanuelli

Santa Maria, RS, Brasil

2006

ads:

___________________________________________________________________________

Todos os direitos autorais reservados a Ivo Roberto Dorneles Prolla. A reprodução de partes

ou do todo deste trabalho só poderá ser feita com autorização por escrito do autor.

Endereço: Rua General Neto, n. 1241/902, Bairro Nossa Senhora de Lourdes, Santa Maria,

RS, 97050-241

Fone (0xx)55 32238914; Fax (0xx) 32216762; End. Eletr: [email protected]

___________________________________________________________________________

Universidade Federal de Santa Maria

Centro de Ciências Naturais e Exatas

Programa de Pós-Graduação em Bioquímica Toxicológica

A Comissão Examinadora, abaixo assinada,

aprova a Dissertação de Mestrado

CARACTERÍSTICAS FÍSICO-QUÍMICAS

DE CULTIVARES DE FEIJÃO (Phaseolus vulgaris L.),

E EFEITOS BIOLÓGICOS DA FRAÇÃO FIBRA SOLÚVEL

elaborada por

Ivo Roberto Dorneles Prolla

como requisito parcial para obtenção do grau de

Mestre em Bioquímica Toxicológica

COMISÃO EXAMINADORA:

___________________________________

Tatiana Emanuelli, Dra.

(Presidente/Orientador)

___________________________________

Liane Nanci Rotta, Dra. (FFFCM-PA)

___________________________________

Maria Rosa Chitolina Schetinger, Dra. (UFSM)

Santa Maria, 13 de dezembro de 2006.

DEDICATÓRIA

À minha mãe Idalina, que lutando contra as adversidades do destino criou-me,

educou-me e me possibilitou ter um destino diferente do seu.

Aos meus irmãos Gladstone, Jorge, Carmem e Fernando que sempre me cuidaram,

apoiaram e valorizaram minha vida profissional.

À minha esposa Alba e à minha filha Luíza, que tiveram paciência e resignação

nos momentos em que não estive presente ou disponível como marido e pai.

Tenham certeza que vocês fizeram parte, de uma forma ou de outra, desta obra.

Muito obrigado!

Amo vocês!

AGRADECIMENTOS

Primeiramente, gostaria de agradecer à minha mãe e aos meus irmãos por terem me

oportunizado viver, crescer, estudar e me tornar o que sou. Ao meu falecido pai, que apesar de

não termos nos conhecido, certamente colaborou e influenciou no que penso e faço.

Ao Dr. Prado Veppo, meu sogro, que me tomou como filho. Apesar de termos

convivido tão pouco nossa convivência foi intensa e marcante. À Zelinha e ao Pity, pelo

acolhimento, carinho, apoio e estímulo para “sempre continuar”.

Agradeço aos colegas do NIDAL que me receberam de forma fraterna, me fizeram

sentir parte do grupo e me auxiliaram nas inúmeras técnicas utilizadas em minha pesquisa.

Gostaria de agradecer às minhas ICs Paula Augusti e Ana Paula Veeck, hoje

mestrandas, pelo auxílio inestimável nas análises de laboratório. Agradeço, também, às alunas

Bruna, Carina e Ana pela valiosa colaboração durante o experimento animal. E deixo um

grande agradecimento ao meu “braço-direito”, IC Roberta Barbosa, que esteve ao meu lado

durante todos os anos da pesquisa. Obrigado pelo auxílio, pelas coisas que me ensinastes, pela

amizade e parceria. Obrigado por ter estado presente em todos os momentos, inclusive quando

eu não estava lá.

À Angélica, secretária do PPGBT, pela atenção com que era tratado sempre que

necessitei.

Gostaria de agradecer à Profa. Dra. Nerinéia Dalfollo Ribeiro, que gentilmente

forneceu as sementes utilizadas neste estudo e me orientou sobre aspectos relacionados à

cultura do feijão, completamente desconhecidos para mim.

A ti, Profa. Dra. Leila Picolli da Silva, que sempre se mostrou acessível e disponível,

que me auxiliou em vários momentos no laboratório e fora dele, que me co-orientou e me

mostrou caminhos alternativos para solucionar problemas que me pareciam sem solução.

Agradeço-te enormemente.

À minha orientadora, Profa. Dra. Tatiana Emanuelli, deixo meu agradecimento

especial. Mesmo sem me conheceres, acreditastes que um médico pediatra poderia trabalhar

em um laboratório de pesquisa, sem causar grandes estragos, e que seria capaz de desenvolver

um estudo sobre um assunto tão distante de minha realidade. Que teve paciência em me

ensinar as inúmeras técnicas às quais tive de aprender; que me ensinou a trabalhar com

planilhas e estatísticas; que me auxiliou na redação dos artigos em inglês; que não me

deixava desanimar quando algo dava errado; e que teve compreensão para aqueles momentos

em que não estive tão presente, pois a família ou a vida profissional me exigiram.

Agradeço ao PPGBT por me permitir ingressar e realizar esta pesquisa. Com ela

espero ter podido colaborar para enaltecer o conceito já existente.

Aos membros da banca, Profa. Dra. Liane Rotta, Profa. Dra. Maria Rosa e Profa. Dra.

Maria Ester, por terem aceitado participar de minha defesa de dissertação e que pacientemente

avaliaram cada item de minha pesquisa. Rosinha e Ester, vocês participaram de minha defesa

de projeto, e com suas observações delinearam outros aspectos os quais tentei seguir. Espero

que este estudo tenha demonstrado minha evolução, e tenham certeza que suas observações

para enriquecê-lo novamente serão de grande valia.

Por fim, gostaria de agradecer de forma muito especial à minha esposa Alba e à minha

filha Luíza pelo apoio, estímulo e, principalmente, compreensão. Nestes últimos anos vocês

tiveram de aprender a conviver com uma intrusa em nosso lar: minha ausência. Foi um tempo

difícil para mim, pois tentava administrar, da melhor maneira possível, tantas atividades

simultaneamente: o magistério superior, o consultório privado, os plantões e o mestrado.

Procurei não descuidar de meus papéis de marido e de pai. Mas agora, finalmente este período

termina, como uma longa gestação. E a dissertação se concretiza no todo, como um filho que

nasce e que dará início a uma nova fase em nossas vidas.

Obrigado a todos vocês.

CONSELHO

Quando te decidires: segue!

Não esperes que o vento

Cubra de flores o caminho.

Nem sequer esperes o caminho.

Cria-o. Faze-o tu mesmo

E parte... Sem lembrar

Que outros passos pararam,

Que outros olhos ficaram te olhando seguir.

(Prado Veppo)

RESUMO

Dissertação de Mestrado

Programa de Pós-Graduação em Bioquímica Toxicológica

Universidade Federal de Santa Maria

CARACTERÍSTICAS FÍSICO-QUÍMICAS

DE CULTIVARES DE FEIJÃO (Phaseolus vulgaris L.),

E EFEITOS BIOLÓGICOS DA FRAÇÃO FIBRA SOLÚVEL

UTOR: IVO ROBERTO DORNELES PROLLA

ORIENTADOR: TATIANA EMANUELLI

Data e Local da Defesa: Santa Maria, 13 de dezembro de 2006.

Foram analisadas as características físico-químicas de sementes cruas de dezesseis

cultivares de feijão comum (Phaseolus vulgaris L.), ao longo de duas safras consecutivas

(2001/2002 e 2002/2003), bem como os teores de amido e fibra alimentar nas sementes após

cozimento e estocagem. Avaliaram-se, também, os lipídeos séricos e a glicose sanguínea de

ratos normolipidêmicos e normoglicêmicos, alimentados com dietas contendo cultivares de

feijão com diferentes relações fibra solúvel/fibra total (FS/FT): dieta Pérola (0,11), dieta

Diamante Negro (0,19) e dieta Iraí (0,26); o grupo controle recebeu dieta padrão (com fibra

insolúvel). Exceto pelos teores de matéria seca, umidade e fibra alimentar total, as cultivares

estudadas mantiveram suas características físico-químicas constantes ao longo das safras.

Conforme a similaridade nos teores de macronutrientes (proteína bruta-PB, fibra alimentar

total, fibra alimentar insolúvel, fibra alimentar solúvel-FS, amido disponível-AD e amido

resistente-AR) as sementes das safras 2001/2002 e 2002/2003 foram categorizadas em quatro

grupos distintos; da mesma forma, em relação aos micronutrientes (Fe, Zn, Mn, Cu, Ca, Mg e

P), quatro grupos puderam ser identificados. As cultivares Guateian 6662 e Rio Tibagi

apresentaram o melhor perfil nutricional (maiores teores de PB, FS, AD, Fe e Zn). A

armazenagem sob refrigeração e o congelamento não determinaram alterações nos teores de

fibra dos grãos cozidos, mas redução do AD e aumento do AR, principalmente naqueles com

AR mais baixo antes do cozimento. Em relação à resposta biológica, os ratos alimentados

com dietas contendo feijão apresentaram valores para colesterol sérico e índice glicêmico

menores que os do grupo controle (p<0,05). Foi observado, também, que apesar do ganho de

peso dos animais ter sido semelhante entre os grupos, os ratos alimentados com as dietas

contendo feijão apresentaram menor retenção de gordura corporal (p<0,05). Os efeitos das

dietas sobre os animais experimentais foram mais expressivos no grupo alimentado com a

dieta Iraí (FS/FT: 0,26).

Palavras-chave: fibra alimentar; fibra insolúvel; amido disponível; amido resistente; conteúdo

mineral; colesterol; curva glicêmica; gordura epididimal.

ABSTRACT

Dissertação de Mestrado

Programa de Pós-Graduação em Bioquímica Toxicológica

Universidade Federal de Santa Maria

PHYSICOCHEMICAL CHARACTERISTICS

OF BEAN CULTIVARS (Phaseolus vulgaris L.),

AND BIOLOGICAL EFFECTS OF SOLUBLE FIBER FRACTION

UTHOR: IVO ROBERTO DORNELES PROLLA

DVISER: TATIANA EMANUELLI

Date and Place of the defense: Santa Maria, December 13th, 2006

Raw seeds of sixteen common bean (Phaseolus vulgaris L.) cultivars were evaluated

along two consecutive harvests (2001/2002 and 2002/2003) concerning their physicochemical

characteristics, as well as the effect of cooking and storage conditions on starch and dietary

fiber contents. Serum lipids and blood glucose levels were also evaluated in normolipidemic-

normoglycemic rats witch were fed diets containing bean cultivars with different soluble

fiber/total fiber ratios (SF/TF): Pérola diet (0.11), Diamante Negro diet (0.19) and Iraí diet

(0.26); control group was fed a standard diet (with insoluble fiber). Except for dry matter,

moisture, and total dietary fiber, cultivars kept their chemical characteristics between

harvests. Regarding similarity among macronutrient levels (crude protein-CP, total dietary

fiber, insoluble dietary fiber, soluble dietary fiber-SF, digestible starch-DS, and resistant

starch-RS) seeds from harvests 2001/2002 and 2002/2003 were categorized into four different

groups; the same was done for micronutrients (Fe, Zn, Mn, Cu, Ca, Mg, and P), and four

groups were also identified. Guateian 6662 and Rio Tibagi were considered the cultivars with

the best nutritional profile (highest levels of CP, SF, DS, Fe, and Zn). Storage under

refrigerated or freezing conditions did not change fiber content of cooked beans, but

decreased their DS content and increased RS content, mainly in seeds with low RS levels

before cooking. Concerning biological response, rats fed bean diets experienced lower values

for serum cholesterol (P<0.05) and lower glycemic indexes (P<0.05). It was also observed a

similar weight gain among groups, however animals fed bean based diets showed lower fat

retention (P<0.05). The effects of bean diets on experimental groups were more remarkable in

animals fed Iraí diet (SF/TF: 0.26).

Keywords: dietary fiber; insoluble fiber; digestible starch; resistant starch; mineral content;

cholesterol; glycemic curve; epididymal fat.

LISTA DE ABREVIATURAS

ACG: área sob a curva glicêmica

AD: amido disponível

AR: amido resistente

Ca: cálcio

Cu: cobre

FB: fibra bruta

Fe: ferro

FI: fibra alimentar insolúvel

FS/FT: relação fibra solúvel/fibra total

FS: fibra alimentar solúvel

FT: fibra alimentar total

g N: gramas de nitrogênio

HC: carboidrato

HDL: “high-density-lipoprotein”

IG: índice glicêmico

LDL: “low density lipoprotein”

Mg: magnésio

Mn: manganês

MS: massa seca

P: fósforo

PB: proteína bruta

RS: Rio Grande do Sul

Zn: zinco

LISTA DE ANEXOS

ANEXO 1 – Roteiro para autores / Guia para a redação e edição de artigo científico a

ser submetido à revista LWT- FOOD SCIENCE AND TECHNOLOGY...............................97

ANEXO 2 – Roteiro para autores / Guia para a redação e edição de artigo científico a

ser submetido à revista BRITISH JOURNAL OF NUTRITION...........................................102

ANEXO 3 – Valores para peso de 1000 grãos e de macronutrientes das cultivares de

feijão das safras 1 (2001/2002) e 2 (2002/2003).....................................................................112

ANEXO 4 – Valores de micronutrientes das cultivares de feijão das safras 1

(2001/2002) e 2 (2002/2003)..................................................................................................113

SUMÁRIO

DEDICATÓRIA .......................................................................................................................4

AGRADECIMENTOS .............................................................................................................5

EPÍGRAFE ...............................................................................................................................7

RESUMO ..................................................................................................................................8

ABSTRACT ..............................................................................................................................9

LISTA DE ABREVIATURAS ..............................................................................................10

LISTA DE ANEXOS .............................................................................................................11

APRESENTAÇÃO .................................................................................................................13

1 INTRODUÇÃO ...................................................................................................................14

2 REVISÃO DA LITERATURA ..........................................................................................18

2.1 A cultura do feijão ............................................................................................................18

2.2 Características físico-químicas dos grãos de feijão .......................................................20

2.3 Alterações secundárias ao processamento doméstico e ao tempo de estocagem ........23

2.4 Propriedades nutritivas e funcionais do feijão ..............................................................25

3 RESULTADOS................... .................................................................................................29

3.1 Manuscrito 1 .....................................................................................................................30

3.2 Manuscrito 2 .....................................................................................................................56

4 DISCUSSÃO ........................................................................................................................84

5 CONCLUSÕES ...................................................................................................................91

6 BIBLIOGRAFIA .................................................................................................................92

7 ANEXOS ..............................................................................................................................97

APRESENTAÇÃO

Os resultados que fazem parte desta dissertação são apresentados sob a forma de

manuscritos, os quais se encontram no item RESULTADOS. As seções Materiais e Métodos,

Resultados, Discussão dos Resultados e Referências Bibliográficas encontram-se nos próprios

manuscritos e representam na íntegra este estudo.

Os itens DISCUSSÃO e CONCLUSÃO contêm interpretações e comentários gerais

referentes aos manuscritos contidos neste estudo.

A BIBLIOGRAFIA refere-se às citações que aparecem nos itens INTRODUÇÃO,

REVISÃO BIBLIOGRÁFICA e DISCUSSÃO desta dissertação.

1 INTRODUÇÃO

Nos últimos anos inúmeras pesquisas foram conduzidas com o objetivo de relacionar o

tipo de dieta consumida pelos povos e as doenças como diabete, deslipidemias, obesidade e

doenças cardiovasculares. Assim, muitos alimentos passaram a ser considerados na

etiopatogenia destas enfermidades. Porém, outros se destacaram pelos efeitos protetores de

seus nutrientes sobre o funcionamento de tecidos, órgãos e sistemas: os chamados alimentos

funcionais. Estes, apresentam propriedades que podem influenciar na evolução e prognóstico

de muitas destas doenças cujas taxas de morbidade e mortalidade são ainda elevadas em nosso

meio.

Uma vez que os alimentos apresentam diferenças marcantes no perfil bioquímico de

seus nutrientes, os efeitos funcionais a eles relacionados podem, também, diferir de forma

significativa. Isto é vital em nutrição humana, principalmente em situações adversas de saúde.

Nestas situações, a prescrição de alimentos funcionais dentro de um plano dietoterápico

específico poderia auxiliar no controle e também na prevenção de muitas enfermidades.

Dos diversos alimentos utilizados pelo homem, as sementes da família das

leguminosas desempenham importante papel na dieta da maioria das populações, sendo o

feijão comum (Phaseolus vulgaris L.) um dos mais consumidos, inclusive no Brasil. É rico

em proteínas (19,6 a 26% da massa seca - MS), carboidratos complexos de baixo índice

glicêmico (64 a 71% da MS) e pobre em gordura (1 a 2% da MS) (VIEIRA, 1967); é fonte

importante de fibras (HARO et al., 1995) e de amido resistente (SAURA-CALIXTO et al.,

1992). Por isto, é um dos alimentos que contempla as recomendações dietéticas atuais.

Estudos já demonstraram que as leguminosas, dentre estas o feijão, possuem

propriedades reguladoras dos níveis de glicemia e insulina (FOSTER-POWELL & MILLER,

1995). Como há estreita relação entre diabete, hiperinsulinemia e deposição de gordura, o

consumo de feijões poderia, de forma preventiva, influenciar no surgimento da obesidade.

Além disto, outros estudos demonstraram que o feijão também é capaz de reduzir os níveis

séricos de colesterol e, assim, o risco de doenças cardiovasculares (ANDERSON et al., 1984;

BAZZANO et al., 2001; HAN et al., 2003).

Dentre os nutrientes encontrados no grão de feijão, a fração fibra solúvel parece

desempenhar um importante papel como alimento funcional. Isto pode ser observado em

estudos que avaliaram os efeitos de dietas contendo feijão como fonte de fibra solúvel e o

comportamento dos lipídeos e glicose sanguíneos após a sua ingestão (ANDERSON &

GUSTAFSON, 1988)

As cultivares de feijão apresentam diferenças agronômicas e tecnológicas notáveis.

Isto ocorre principalmente devido ao perfil genotípico da planta. Porém, o melhoramento

genético e as adversidades climáticas impostas à planta também influenciam sobremaneira

este perfil. Estas alterações acabam por afetar a composição química das sementes, com

aperfeiçoamento de algumas características em detrimento de outras. Isto pode ser

comprovado por estudos envolvendo cultivares de Phaseolus vulgaris plantadas em diferentes

regiões do mundo, onde as sementes têm apresentado diferenças marcantes na sua

composição química (VIEIRA, 1967; SOTELO et al., 1995; YANEZ et al., 1995; SAMMAN

et al., 1999; CASTELLÓN et al., 2003).

No Rio Grande do Sul (RS), assim como em nosso país, a lista de cultivares de feijão

indicadas para o plantio é extensa. Uma vez que o perfil nutricional dos grãos pode ser

influenciado pelo ano de plantio, a variabilidade na composição química das cultivares aqui

plantadas e consumidas também deve ser significativa. Além disto, o processamento

doméstico habitual dos grãos (cozimento e refrigeração) poderia determinar outras alterações

relevantes na sua composição química.

Se todas estas alterações realmente determinam mudanças bioquímicas profundas nos

grãos de feijão, estas diferenças poderiam ser mais bem exploradas na nutrição humana.

Assim, cultivares de feijão com teores elevados da fração fibra solúvel, por exemplo,

poderiam ser preferidas dentro de um plano de orientação dietética para pacientes portadores

de deslipidemias, diabete, obesidade e doenças cardiovasculares. Além disso, estas cultivares

seriam fortemente recomendadas para o consumo geral, uma vez que deteriam propriedades

preventivas em pessoas com risco aumentado de desenvolverem alguma daquelas

enfermidades.

Este estudo objetiva avaliar a hipótese de que feijões apresentam variações

importantes nos teores de fibra solúvel e que cultivares com teores elevados desta fração

apresentam efeito redutor dos lipídeos séricos e da glicemia, mesmo em situações em que

estes valores encontram-se dentro da normalidade. Assim, estas cultivares poderiam ser

preferentemente indicadas na orientação dietética de pacientes com ou em risco de

desenvolverem doenças relacionadas ao metabolismo dos lipídios e/ou da glicose. Estes

resultados reforçariam a idéia de que tabelas de composição alimentar devem ser mais

completas e detalhadas quanto aos nutrientes de relevância clínica. Ainda, o cruzamento de

cultivares de feijão com características nutricionais peculiares poderia ser estimulado, a fim

de que fossem obtidas novas cultivares com perfis bioquímicos mais adequados a outras

enfermidades crônicas prevalentes.

Desta forma, o presente estudo foi delineado com base em questionamentos que

nortearam o desenrolar desta pesquisa. Foram eles:

1. As cultivares de feijão (Phaseolus vulgaris L.) plantadas e consumidas em

nosso meio diferem significativamente entre si quanto às características físico-

químicas?

2. Uma mesma cultivar pode alterar significativamente suas características físico-

químicas de uma safra para outra?

3. Processos de cozimento e armazenamento podem alterar os teores de amido e

de fibra do feijão?

4. As diferenças genéticas e as alterações no perfil químico (secundárias ao

processamento doméstico), se existirem, atingem de forma relevante a fração

fibra solúvel?

5. Se a diferença nos teores de fibra solúvel for significativa, cultivares com

teores mais elevados podem determinar redução nos níveis de lipídeos e

glicose sanguíneos, mesmo em situações de normolipidemia e normoglicemia?

Para respondermos a estes questionamentos elaboramos os seguintes objetivos

específicos:

1. Determinar e comparar as características físico-químicas de sementes cruas de

dezesseis cultivares de feijão comum (Phaseolus vulgaris L.) recomendadas

para plantio no RS;

2. Avaliar a persistência destas características ao longo de duas safras

consecutivas (2001/2002 e 2002/2003);

3. Estudar os efeitos da estocagem das sementes após cozimento seguido de

refrigeração ou congelamento sobre teores de amido disponível, amido

resistente, fibra alimentar total, insolúvel e solúvel;

4. Avaliar os efeitos de dietas experimentais contendo cultivares de feijão com

diferentes relações fibra solúvel/fibra total sobre os níveis de lipídeos séricos

(triglicerídeos, colesterol total, colesterol HDL), glicemia e outros

parâmetros biológicos em ratos normolipidêmicos e normoglicêmicos.

2 REVISÃO DA LITERATURA

2.1 A cultura do feijão

Existem várias espécies de sementes que, maduras, servem como alimento a uma

grande parte da população mundial. Algumas destas são produzidas por plantas chamadas

leguminosas graníferas onde cerca de 20 espécies são utilizadas na alimentação em

quantidades apreciáveis, numa ou noutra região do mundo.

As mais importantes espécies de leguminosas são o guandu, o caupi, a ervilha, a

lentilha, o grão-de-bico, a fava, o feijão-fava, os feijões asiáticos do gênero Vigna, o

amendoim, a soja e o feijão comum. Este último, segundo relatos na literatura, já fazia parte

da dieta de muitos povos antepassados. No Peru, foram encontrados restos de feijão comum

com 8.000 anos; em dois locais no México foram encontrados restos com 4.300 a 7.000 anos

de idade. Mas, no norte da Argentina foram encontrados os restos mais antigos até agora

descritos, com 6.700 a 9.600 anos de idade (VIEIRA et al., 2001).

No Brasil o cultivo do feijão é bastante difundido em todo o território nacional,

principalmente como cultura de subsistência em pequenas propriedades. Nosso país é o

segundo produtor mundial de feijão (Phaseolus), perdendo apenas para a Índia e seguido pela

China; é o primeiro na espécie vulgaris, seguido pelo México. Apesar disto, a produção

brasileira é insuficiente para abastecer o mercado interno, necessitando importar este produto

de outros países da América Latina e dos Estados Unidos (YOKOYAMA, 2002).

O feijão comum ou simplesmente feijão pertence à família Leguminosae, sub-família

Papipilionoideae, gênero Phaseolus cujo nome científico é Phaseolus vulgaris L.. É uma

planta herbácea, trepadora ou não, levemente pubescente, cujo ciclo de vida varia de,

aproximadamente, 65 a 120 dias, dependendo da cultivar e das condições e época de plantio.

Pode apresentar quatro tipos de hábitos de crescimento sendo um tipo chamado determinado e

outros três definidos como indeterminados. Com vagens retas ou ligeiramente curvas,

achatadas ou arredondadas, com bico reto ou curvado, em geral com 9 a 12 cm de

comprimento e com 3 a 7 sementes (ALMEIDA & CANÉCHIO FILHO, 1987; VIEIRA et al.,

2001).

O gênero Phaseolus compreende aproximadamente 55 espécies das quais apenas

cinco são cultivadas: o feijoeiro comum (Phaseolus vulgaris); o feijão de lima (P. lunatus); o

feijão ayocote (P. coccineus); o feijão tepari (P. acutifolius); e o P. polyanthus (EMBRAPA

ARROZ e FEIJÃO, 2004).

O feijão é uma planta muito exigente. Para plantar feijão com êxito comercial, a

escolha da área onde será feita a cultura é de importância fundamental. Devem-se preferir

áreas que tenham outono e primavera mais ou menos longos, suficientes para completar o

ciclo do feijoeiro, não se prestando aquelas onde o verão e o inverno são muito rigorosos. A

temperatura média ótima para a cultura varia de 10

a 25

C (ALMEIDA & CANÉCHIO

FILHO, 1987). A alta temperatura (superior a 30

C) pode ocasionar, dependendo da cultivar,

diminuição da percentagem de flores que vingam e do número de sementes por vagem. Por

outro lado, as baixas temperaturas são desfavoráveis ao crescimento, e as geadas podem

causar enormes danos à cultura (VIEIRA et al., 2001).

O feijoeiro prospera em diferentes tipos de solos, exceto nos compactos, nos salinos e

nos encharcados. Os solos preferidos são os de textura areno-argilosa, leves, soltos, ricos em

matéria orgânica e em elementos fertilizantes, e com pH entre 6 a 7,5, considerado adequado

para um crescimento ótimo (ALMEIDA & CANÉCHIO FILHO, 1987).

Tanto o excesso quanto a escassez de água são prejudiciais. A alta umidade pode

favorecer as doenças, pois o feijoeiro não tolera água estagnada, mesmo que por curto espaço

de tempo. A seca, também prejudicial, pode ser contornada pela irrigação, principalmente na

época da floração e do vageamento (VIEIRA et al., 2001). A precipitação pluviométrica ideal

na época do plantio situa-se na faixa dos 100 mm (ALMEIDA & CANÉCHIO FILHO, 1987).

Já durante a colheita, condições de seca são essenciais para a obtenção de sementes de boa

qualidade (VIEIRA et al., 2001).

No Brasil o feijão pode ser plantado mais de uma vez por ano sendo comum, entre os

pequenos agricultores, a prática deste cultivo de permeio com mandioca, cana, café e outras

culturas, principalmente com o milho. Desta forma, é possível explorar a cultura em três

épocas diferentes no mesmo ano: a safra “das águas”, cujo plantio é feito de agosto a

novembro, com predominância na região sul; o plantio “da seca”, realizado de janeiro a

março, abrangendo a maioria dos estados produtores; e o plantio “de inverno”, de abril a

julho, realizada nas regiões centro-oeste e sudeste. As duas primeiras safras são responsáveis

por 90% da produção nacional e provém de lavouras de pequenos e médios produtores, com

baixo nível tecnológico; os outros 10% provém da safra “de inverno”, de lavouras com alto

nível tecnológico principalmente quanto à irrigação, determinando uma alta produtividade por

hectare plantado (EMBRAPA ARROZ e FEIJÃO, 2004).

As cultivares de feijão plantadas no Brasil terminam o ciclo de vida em 80 a 100 dias

(alguns em menos tempo: 65 a 75 dias) e a colheita costuma ser feita manualmente,

mecanicamente ou pela combinação de ambas.

O feijão recém colhido normalmente apresenta-se com umidade alta, em torno de

15%, e muitas vezes com as sementes abrigando ovos de carunchos. Por isto, logo após a

colheita, deve-se proceder à secagem (com redução da sua umidade para 10 a 11%),

beneficiamento, fumigação e estocagem das sementes em ambiente arejado, com baixa

umidade, a temperatura de 21

C mantendo-as protegidas de insetos, de carunchos e da luz.

Para temperaturas mais elevadas (26,5

C), a umidade das sementes deve ser rebaixada até 8%

para uma conservação segura. Desta forma, as sementes podem ser estocadas por dois anos

com manutenção adequada de seu poder germinativo (VIEIRA et al., 2001).

2.2 Características físico-químicas dos grãos de feijão

A semente do feijão pode apresentar as mais diferentes cores: branca, negra, vermelha,

amarela, parda, rósea, creme, alaranjada, bege, roxa e outras, muitas vezes com estrias ou

sarapintas de diferentes cores. Há também as bicolores e as que exibem uma segunda cor no

hilo. Atualmente, em nosso meio, os tipos comerciais mais aceitos são: o carioca (bege com

estrias pardacentas), o preto e o mulatinho (bege). As demais têm menor aceitação comercial

ou aceitação limitada a certas regiões do país. A massa das sementes também é bastante

variável, com pesos de 12 até 70 gramas por 100 unidades. Os feijões carioca, preto e

mulatinho, por serem pequenos, em geral pesam de 15 a 25 g/100 unidades. Já os feijões do

tipo manteigão, que são graúdos, apresentam pesos geralmente superiores a 35 g/100

unidades, alguns ultrapassando 50 g. Geralmente as formas silvestres de P. vulgaris produzem

sementes menores que as formas cultivadas (VIEIRA et al., 2001)

VASQUEZ-CARRILLO & CARDENAS-RAMOS (1992) avaliaram algumas

características físicas, tecnológicas e protéicas de 4 cultivares de feijão (P. vulgaris)

desenvolvidas no México e 12 sementes de feijões selvagens, sendo 8 mexicanas e 4 sul-

americanas. As sementes sul-americanas mostravam um tamanho similar entre si (em média

10,4 g/100 sementes), mas diferentes capacidades de absorver água (de 36 a 64%),

percentagens de casca e sólidos, e teores de proteína (de 23,8 a 27,2%). As sementes

selvagens mexicanas foram as menores do estudo (2,8 g/100 sementes) e com a menor

capacidade de absorver água. Estas continham a maior quantidade de casca e durante o

processo de cozimento perdiam pequena quantidade de solutos para a água. O conteúdo

protéico variou de 21,3 a 24,6%. As sementes cultivadas apresentaram as melhores

características físicas e tecnológicas, o menor tempo de cozimento, mas o menor teor protéico

do estudo (22,3%).

No Brasil, a lista de cultivares indicadas para plantio é extensa. Cada estado tem a sua

própria recomendação, às vezes com indicação por região. Os feijões dos tipos carioca e

preto, seguidos pelo mulatinho são os mais indicados. No Rio Grande do Sul, as cultivares

indicadas para as safras 2002/2003 e 2003 foram: Guapo Brilhante, Macotaço, Diamante

Negro, Pérola, FTS Magnífico, FTS Soberano, TPS Bonito, TPS Bionobre e TPS Nobre

(BRASIL, 2002 a; 2002 b).

É sabido que a composição química das sementes é bastante variável, dependendo da

cultivar. VIEIRA (1967) avaliou a composição de 17 cultivares de feijão e encontrou, com

base na matéria seca, as seguintes variações: proteína bruta, de 19,6 a 26,0%; extrato etéreo,

de 1,1 a 1,9%; cinzas brutas, de 3,3 a 4,3%; fibra bruta, de 2,8 a 5,5%; e extrato não-

nitrogenado, de 63,9 a 70,9%. A Embrapa, em seus comunicados técnicos, cita valores

semelhantes (matérias protéicas 22%, matérias graxas 1,5%, cinzas 4%, fibras 4,5%, umidade

12% e carboidratos 56%).

As variações na composição química podem ser atribuídas às modificações genéticas

impostas à planta ou às condições ambientais durante o plantio. Em Fortaleza, Ceará,

CASTELLÓN et al. (2003) avaliaram a fração lipídica de 6 cultivares comerciais de feijão

caupi, e encontraram diferenças importantes nos teores de ácido palmítico, ácido linoléico e

ácidos graxos pentacosanóico e eicosanóico. Concluíram que o melhoramento genético pode

determinar diferenças quantitativas e qualitativas na composição bioquímica. Concluíram,

também, que mudanças na capacidade germinativa, resistência a predadores, etc. podem

alterar a expressão de genes codificadores de síntese de moléculas relevantes, levando a

diferentes composições químicas.

Em um estudo publicado em 1999, os autores avaliaram a composição de algumas

variedades de feijão plantadas em 7 regiões da Argentina (SAMMAN et al., 1999). Estes

autores encontraram valores variáveis para o amido (12 a 14%), para as proteínas (18 a

22%), para a gordura (0,7 a 1,2%) e também para os minerais (cobre: 0,8 a 1,2 mg/100 g;

ferro: 9 a 18 mg/100 g; zinco: 2,5 a 4,0 mg/100 g; e fósforo: 295 a 542 mg/100 g) e

concluíram que conforme a região, diferenças importantes na composição química do feijão

são encontradas.

SOTELO et al. (1995), no México, avaliando a composição química de feijões

selvagens e cultivados, observaram que estes últimos, apesar de apresentarem menores

proporções de proteínas (21,7 vs. 25,5%), cinzas (4,2 vs. 5,2%) e fibra bruta (5 vs. 7,1%),

maiores quantidades de carboidratos (68,1 vs. 61,6%) e melhor perfil de aminoácidos. Com

isto, demonstraram que, sob o ponto de vista químico, a domesticação parece ter efeitos

positivos.

O conteúdo protéico dos grãos dos cereais varia, aproximadamente, de 8 a 16%. Uma

dieta de cereais em quantidade adequada pode satisfazer as necessidades de calorias do

consumidor, mas não lhe fornecerá a quantidade de proteínas, especialmente quando se trata

de crianças e mulheres grávidas. Nos países com melhores condições nutricionais, esse déficit

protéico é compensado pelos alimentos de origem animal, mais caros que os de origem

vegetal. Já nos países em desenvolvimento da África, da Ásia e da América Latina, as

leguminosas graníferas são utilizadas como fonte muito mais barata de proteínas e, por este

motivo, são chamadas de “carne do pobre”. Contêm de 18 a 35% de proteínas, sendo que a

soja pode alcançar mais de 40%.

Enquanto as sementes de leguminosas são ricas em lisina, os cereais são ricos em

aminoácidos sulfurados (metionina e cistina). Desta forma, a proporção mais adequada entre

cereal e leguminosa que equilibraria as deficiências parece ser de 2,6:1. Isto foi demonstrado

por ABD-EL-SAMEI et al. (1984), que realizaram um estudo comparativo sobre a

composição de aminoácidos em três variedades locais de sementes de P. vulgaris. Eles

observaram que a composição dos aminoácidos foi semelhante, sendo que todos

apresentavam deficiência de aminoácidos sulfurados, um teor elevado de lisina (8,1 a 8,6 g/16

g N), ausência de cistina, fenilalanina e tirosina nos extratos das três variedades. Verificaram,

também, uma correlação negativa entre o conteúdo de aminoácidos sulfurados e percentagem

de proteínas nas sementes.

Em 1995, YANEZ et al. publicaram um artigo onde avaliavam a composição química

e a qualidade biológica da proteína de 5 cultivares de feijão comum recém lançadas para uso

no Chile. O conteúdo protéico bruto encontrado variava de 22 a 27% e a resposta biológica

em ratos mostrou que os animais alimentados com a cultivar com mais proteínas ganhavam

mais peso e apresentavam maior captação/incorporação protéica.

Além dos aspectos inerentes às proteínas das leguminosas, as mesmas ainda

influenciam a formação de outros compostos de relevantes propriedades nutricionais; dentre

eles, o amido resistente (AR). SAURA-CALIXTO et al. (1992) estudaram a formação de AR

em feijão desproteinizado e não desproteinizado, inteiro e moído, após cocção e

congelamento. Os maiores teores de AR foram obtidos nas preparações com feijão inteiro (3,7

a 8,7%). O feijão moído e o moído e desproteinizado apresentaram os menores teores (1,6 e

0,9%, respectivamente). Concluíram que a presença de proteína e o tamanho das partículas

são os principais fatores que afetam a formação de AR.

Em relação às fibras, as leguminosas são reconhecidamente fontes importantes deste

polissacarídeo. Em um estudo que avaliou a composição química, fibra dietética e conteúdo

mineral de 15 alimentos freqüentemente consumidos no noroeste do México, o feijão foi o

alimento que apresentou os maiores teores de fibra (9,2 g/100 g) (HARO et al., 1995).

A literatura pertinente contém várias publicações envolvendo características físico-

químicas de cultivares de feijão das mais diferentes regiões do globo. Este é o primeiro estudo

brasileiro que caracteriza e avalia a persistência ao longo de 2 safras de parâmetros físico-

químicos em um número expressivo de cultivares de Phaseolus vulgaris L. plantadas e

consumidas em nossa região.

2.3 Alterações secundárias ao processamento doméstico e ao tempo de estocagem

Além das alterações nas características químicas das sementes devido à variedade

genética e aos fatores ambientais, processos de cozimento e armazenamento também podem

produzir alterações importantes na composição dos grãos, principalmente nos teores de amido

e fibra (KUTOS et al., 2003; VARGAS-TORRES et al., 2004).

É dito que as condições e o tempo de estocagem podem alterar algumas propriedades

físicas e químicas dos grãos. No entanto, em um estudo realizado por HERNANDEZ-

UNZON & ORTEGA-DELGADO (1989), no México, avaliando alterações possíveis em

sementes de feijão estocadas por até oito anos, não foram observadas diferenças significativas

nas composições químicas. Porém, sementes com 5 a 6 anos de estocagem absorviam mais

água que aquelas com menos tempo, mas custavam mais a cozinhar. A diferença realmente

importante observada foi a redução entre 94 e 98% do ácido fítico durante a estocagem longa.

Além do tempo de armazenamento, os diferentes métodos de cocção podem, ou não,

modificar química e fisicamente os grãos. Um estudo realizado na Espanha avaliou as

propriedades nutricionais após o cozimento de feijões por extrusão (MARTIN-CABREJAS et

al., 1999). Para isto, foram utilizados tanto feijões frescos quanto feijões armazenados por 6

semanas e por 1 ano. Observaram aumento do tempo de cozimento destes de 7,7 e de 12

vezes, respectivamente, devido à dureza que se instalou. Nas amostras extrusadas houve

incremento na absorção de água devido à maior proporção de amido gelatinizado. A extrusão

causou, também, redistribuição da fibra insolúvel para solúvel, embora a fibra dietética total

permanecesse igual. Não observaram, porém, diferenças físicas e/ou químicas entre feijões

estocados ou frescos após o processo de extrusão.

No Chile, ESTEVEZ et al. (1991), estudando os efeitos do cozimento e secagem em

várias leguminosas, observaram que nos feijões das variedades Tortola e Coscorron, não

havia mudanças significativas nas proteínas, mas sim o aumento da digestibilidade das

mesmas.

Um estudo italiano avaliou de forma comparativa os efeitos do cozimento

convencional e ao microondas de grão-de-bico e de feijão comum. Os feijões cozidos ao

microondas apresentaram uma redução drástica no tempo de cozimento (de 55 para 9 min),

uma menor perda sólida para a água de cozimento (de 7,5 para 4,5 g/100 g de semente seca de

feijão) e um aumento da digestibilidade do amido, devido à redução do amido resistente (de

32,4%, na semente crua, para 10% após o cozimento) e à elevação do amido rapidamente

digerível (de 27,5% para cerca de 80%). Houve, também, uma redistribuição dos

polissacarídeos não amiláceos de insolúveis para solúveis, mas sem alteração nos teores totais

(MARCONI et al., 2000).

Na Guatemala, ACEVEDO et al. (1994) avaliaram as alterações decorrentes do

processo de cozimento e fritura de feijões pretos. Observaram aumento da fibra dietética

insolúvel de 18,1% no feijão cozido para 22,4% no feijão frito; diminuição da fibra dietética

solúvel de 8,4 para 6,6% nestas mesmas preparações, assim como redução nos teores de

amido (34,5 para 31,3%). A digestibilidade e a qualidade protéica, no entanto, reduziram-se

do feijão cozido para o frito, correlacionando-se com a fibra dietética insolúvel.

Os estudos envolvendo a fração fibra alimentar são, ainda, controversos sendo que

tanto o aumento quanto a redução nos teores de fibra total, solúvel e insolúvel de feijões

cozidos foram relatados (HUGHES & SWANSON, 1989; KUTOS et al., 2003). No entanto,

estudos sobre os efeitos do cozimento seguido de armazenamento nos níveis destes

carboidratos não foram encontrados em feijões.

Quanto à fração amido, alguns autores demonstraram redução nos níveis de amido

disponível e aumento nos de amido resistente em feijões cozidos estocados a 4°C (VARGAS-

TORRES et al., 2004); outros, ao contrário, encontraram aumento do amido disponível

(OSORIO-DIAZ et al., 2003); porém LANDA-HABANA et al. (2004) não encontraram

alterações.

Como visto, a composição química dos grãos de feijão pode ser profundamente

alterada após processos de cozimento e armazenamento sob refrigeração. Estas mudanças

podem, assim, afetar a digestibilidade e, conseqüentemente, o valor nutricional de dietas

formuladas com esta leguminosa.

2.4 Propriedades nutritivas e funcionais do feijão

As propriedades nutritivas relacionadas ao feijão comum baseiam-se no fato de ser

fonte rica de proteínas (19,6 a 26% da MS), de carboidratos complexos de baixo índice

glicêmico (64 a 71% da MS) e pobre em gordura (1 a 2% da MS) (VIEIRA, 1967), o que o

torna um alimento apropriado às recomendações dietéticas atuais. É considerado a “carne do

pobre” em função de seu elevado teor protéico que, juntamente com o arroz, fornece os

aminoácidos necessários à nutrição humana.

Além disto, apresenta muitos efeitos funcionais atribuídos a sua composição química

peculiar, pois é também uma fonte importante de fibras (HARO et al., 1995) e de amido

resistente (SAURA-CALIXTO et al., 1992).

Há muitos anos, pesquisas são desenvolvidas no intuito de relacionar os alimentos

ingeridos pelos povos e o surgimento e a evolução de doenças crônicas. Estas, que

tipicamente cursam por dez ou mais anos, incluem principalmente o diabete melito, as

deslipidemias, a obesidade e as doenças cardiovasculares. Estudos em animais e em humanos

já demonstraram efeitos benéficos das leguminosas sobre algumas destas doenças, inclusive

efeitos protetores do feijão sobre o surgimento de câncer (CORREA, 1981; HUGHES et al.,

1997; SING & FRASER, 1998; HANGEN & ENNINK, 2003). O mecanismo pelo qual

esta proteção ocorre e qual componente tem propriedades anticarcinogênicas ainda não são

conhecidos. O que se sabe é que níveis elevados de insulina (GIOVANNUCCI, 1995;

SANDHU et al., 2002) e/ou altos níveis de glicemia (MCKEOWN-EYSSEN, 1994) podem

estimular o surgimento de alguns tipos de câncer como o dos cólons. Sabe-se, também, que o

consumo de alimentos com alto índice glicêmico por períodos longos pode levar à

hiperinsulinemia, resistência à insulina e diabete melito tipo dois. Baseado nisto, um

mecanismo provável pelo qual feijões inibiriam o surgimento de câncer estaria relacionado à

regulação da glicemia e da insulina, uma vez que é considerado um alimento de baixo índice

glicêmico (IG) (FOSTER-POWELL & MILLER, 1995).

Na atualidade, interações existentes entre dieta de elevado IG, diabete e obesidade são

muito estudadas. Alimentos com alto IG estimulam a fome e levam à seleção progressiva de

alimentos de IG sempre elevados. Forma-se, assim, um ciclo vicioso com ingestão

preferencial de alimentos densamente calóricos, hiperglicemia e hiperinsulinemia (LUDWIG,

2002). As duas últimas, juntamente com a obesidade desenvolvida, são reconhecidamente

fatores de risco para o câncer e patologias cardiovasculares, respectivamente.

Além dos distúrbios metabólicos já mencionados, as deslipidemias constituem um

risco importante para as doenças do coração. É sabido que uma redução de 1% nos níveis de

colesterol total reduzem em 2% o risco de uma pessoa desenvolver esse tipo de afecção

(RIFKIND, 1984). Os grãos de feijão comum têm demonstrado um importante efeito redutor

dos níveis séricos de lipídios (FUKUSHIMA et al., 2001). Tanto em animais (HAN et al.,

2003) quanto em humanos (ANDERSON et al., 1984; BAZZANO et al., 2001) estudos

demonstram que o feijão é capaz de reduzir os níveis séricos de colesterol e,

conseqüentemente, o risco de doenças cardiovasculares. Em pacientes hiperlipidêmicos, a

fração solúvel da fibra de feijão reduziu o colesterol total (13 a 26%), cholesterol HDL (5 a

20%) e triglicerídeos (3 a 25%) (ANDERSON & GUSTAFSON, 1988). Embora alguns

autores tenham atribuído este efeito à fração amido, presumivelmente ao conteúdo de

saponinas (AMIGO et al., 1992), a fibra solúvel parece ser realmente a porção ativa do grão

(ALLER et al., 2004).

Poucos estudos avaliaram os níveis de fibra dietética e de AR em feijões (KUTOS et

al., 2003; VARGAS-TORRES et al., 2004; LANDA-HABANA et al., 2004), enquanto muitos

estudos avaliaram o conteúdo de amido total e fibra bruta, os quais não fornecem dados

esclarecedores sobre as implicações nutricionais destes componentes (VIEIRA, 1967;

ANTUNES et al., 1995; CASTELLÓN et al., 2003; LEMOS et al., 2004; SHIMELIS &

RAKSHIT, 2005). Os carboidratos são a maior fração encontrada nas sementes de feijão. O

conhecimento atual sobre as propriedades do amido indica que uma fração deste carboidrato é

resistente à digestão enzimática no intestino delgado. Esta porção é denominada amido

resistente (AR). Este pode ser um substrato para o processo de fermentação nos cólons com

efeitos benéficos para a saúde humana, semelhante àqueles determinados pela fibra dietética.

O feijão comum apresenta, também, um efeito redutor da glicose plasmática (PARI &

VENKATESWARAN, 2003). Esta propriedade tem sido relacionada não só à digestibilidade

do amido, mas aos conteúdos de proteínas e de fibras. A fração fibra parece reduzir a resposta

glicêmica devido à redução do esvaziamento gástrico e das taxas de absorção intestinal

(THORNE et al., 1983). Esta resposta glicêmica é avaliada pelos valores de glicemia ao longo

do tempo após a ingestão do alimento que é conhecida como curva glicêmica. Porém,

atualmente, tem sido expressa como índice glicêmico (IG) ou área sob a curva glicêmica

(ACG). Dietas com elevado IG estão associadas a maiores respostas insulinêmicas e risco

aumentado de obesidade (PAWLAK et al., 2001). O feijão comum é considerado um alimento

de baixo IG e, por isso, esta leguminosa pode ter importante papel na nutrição humana.

É sabido que grãos de feijão são excelente fonte de fibra alimentar, fornecendo uma

mistura de fibras solúveis e insolúveis (MESSINA, 1999) com todos os efeitos notáveis

relacionados a elas. Entretanto, as cultivares de feijão podem diferir significativamente em

suas composições químicas, incluindo a fração fibra alimentar. Desta forma, suas

propriedades sobre os lipídios e a glicose sanguíneos também podem ser variáveis.

Até o momento, a maioria dos estudos relacionados aos efeitos de dietas baseadas em

feijões foram realizados em ratos hipercolesterolêmicos (DABAI et al., 1996; ROSA et al.,

1998 a; 1998 b) ou com diabete induzido (PARI & VENKATESWARAN, 2003). Nestes

modelos, o consumo de feijões melhorou significativamente os níveis séricos de gordura e de

glicose. No entanto, não há relatos na literatura pertinente de estudos que tenham testado

dietas contendo teores diferenciados de fibra solúvel de feijão sobre lipídeos e glicemia

sanguíneos em animais metabolicamente normais.

3 RESULTADOS

Os resultados desta dissertação estão apresentados sob a forma de manuscritos, os

quais se encontram aqui organizados. As apresentações dos manuscritos estão baseadas na

versão para submissão, sendo que os roteiros para os autores estão anexados.

3.1 Manuscrito 1

CULTIVAR, HARVEST YEAR, AND STORAGE CONDITIONS AFFECTING

COMPOSITION OF COMMON BEANS (Phaseolus vulgaris L.)

Manuscrito submetido à revista

LWT-FOOD SCIENCE AND TECHNOLOGY

Cultivar, harvest year, and storage conditions affecting composition of

common beans (Phaseolus vulgaris L.)

Ivo Roberto Dornelles Prolla

1,2

, Roberta Garcia Barbosa

, Ana Paula de Lima Veeck

, Paula

Rossini Augusti

, Leila Picolli da Silva

, Nerinéia Dalfollo Ribeiro

, Tatiana Emanuelli

1,*

Núcleo Integrado de Desenvolvimento em Análises Laboratoriais (NIDAL), Departamento

de Tecnologia e Ciência dos Alimentos, Centro de Ciências Rurais, Universidade Federal de

Santa Maria, Camobi, 97105-900, Santa Maria, RS, Brasil.

Departamento de Pediatria e Puericultura, Centro de Ciências da Saúde, Universidade

Federal de Santa Maria, Camobi, 97105-900, Santa Maria, RS, Brasil.

Departamento de Zootecnia, Centro de Ciências Rurais, Universidade Federal de Santa

Maria, Camobi, 97105-900, Santa Maria, RS, Brasil.

Departamento de Fitotecnia, Centro de Ciências Rurais, Universidade Federal de Santa

Maria, Camobi, 97105-900, Santa Maria, RS, Brasil.

* Corresponding author. Tel.: +55 55 3220 8547; fax: +55 55 3220 8353.

E-mail address: tatiem[email protected] (T. Emanuelli).

Corresponding author:

Tatiana Emanuelli

Núcleo Integrado de Desenvolvimento de Análises Laboratoriais (NIDAL)

Departamento de Tecnologia e Ciência dos Alimentos

Centro de Ciências Rurais

Universidade Federal de Santa Maria

Campus – Camobi, 97105-900

Santa Maria, RS - Brasil

Telephone: +55 55 3220 8547

Fax: +55 55 3220 8353

E-mail:

tatiemanuelli@smail.ufsm.br

Abstract

Sixteen common bean cultivars were compared concerning the physicochemical

characteristics of their raw seeds along two consecutive harvests, as well as the effect of

storage conditions on starch and dietary fiber content of cooked beans. It was possible to

identify groups of cultivars with different nutritional features. Bean cultivars were

categorized into four different groups according either to their macronutrient contents (crude

protein-PROT, total dietary fiber-TDF, insoluble dietary fiber-IDF, soluble dietary fiber-SDF,

digestible starch-DS, and resistant starch-RS) or to their micronutrient levels (Fe, Zn, Mn, Cu,

Ca, Mg, and P). Guateian 6662 and Rio Tibagi appeared to be the most adequate cultivars to

prevent nutritional deficiencies, because they had high PROT, DS, Fe, and Zn content. The

high dietary fiber and RS content of cultivars Iraí, Minuano, and TPS Bonito suggests that

they could have beneficial role in controlling blood lipid and glucose levels. Cooked beans

had a decrease in DS and an increase in RS content after storage (4

C or -20

C), but these

changes were more prominent in beans that had low RS content before cooking than in those

of high RS content. TDF, IDF, and SDF did not change after storage.

Keywords: Phaseolus vulgaris; Dietary fiber; Digestible starch; Resistant starch; Mineral

content.

1. Introduction

Common beans (Phaseolus vulgaris L.) are grown and consumed throughout the

world. They play an important role in the nutrition of low-income people especially in

developing countries where they are often the most important dietary source of protein,

carbohydrate, dietary fiber, and minerals (Tharanathan & Mahadevamma, 2003). It is

noteworthy that protein energy undernutrition and micronutrient deficiencies in childhood can

be prevented if beans and cereals are appropriately combined. Besides the nutritional role,

bean consumption has other potential benefits for human health like lowering the risk of colon

cancer and of heart disease, reducing total and LDL cholesterol, and regulating blood glucose

and insulin levels (The Michigan Bean Commission, 2006).

Different chemical characteristics can be found in beans according to the genetic

variety (Barampama & Simard, 1993; Kigel, 1999). Genetic research concerning bean culture

is mainly aimed at improving productivity and resistance to field pests and environmental

stress. Although, there is evidence that it may also change physicochemical characteristics of

seeds and affect their nutritional value, studies concerning these changes in beans are still rare

and limited to few cultivars (Augustin, Beck, Kalbfleish, Kagal, & Mathews, 1981;

Barampama & Simard, 1993; Nunez-Gonzalez et al., 2002).

Nutrient profile of beans may also be affected by environmental factors (Samman,

Maldonado, Alfaro, Farfan, & Gutierrez, 1999), which could make it difficult to obtain

standard nutritional values for seeds cultivated in different regions and from different

harvests. However, some studies in cereal cultivars (oat, rice, and wheat) indicate that despite

the changes in absolute values due to environmental factors, cultivars may keep a standard

compositional pattern, i.e. higher or lower starch or protein content (Silva, 2002; Storck,

Silva, & Fagundes, 2005).

Besides these changes in chemical characteristics due to genetic and environmental

factors, certain processing techniques, such as cooking and storage conditions, can also

produce important changes in starch, fiber, and other components of legume seeds (Kutos,

Golob, Kač, & Plestenjak, 2003; Vargas-Torres, Osorio-Diaz, Islas-Hernández, Tovar,

Paredes-Lopéz, & Bello-Pérez, 2004). These changes may affect the digestibility and

nutritional value of foods containing common bean seeds. All this variability has remarkable

importance for strict diets that are based on food composition tables, which usually do not

show specific values for different bean cultivars, neither their possible changes along harvest

years. Besides, bean seeds of better nutritional quality could be supplied for low-income

populations around the world.

Carbohydrates are the major component of beans. Current knowledge on nutritional

features of starch indicates that a fraction of this carbohydrate is resistant to enzyme digestion

in the small intestine. This resistant starch can be a substrate for the fermentation process in

the colon with important benefits for human health, similar to the dietary fiber. However,

relatively few studies evaluated resistant starch and dietary fiber content of common beans

(Kutos et al., 2003; Vargas-Torres et al., 2004; Landa-Habana, Piña-Hernández, Ágama-

Acevedo, Tovar, & Bello-Pérez, 2004), while most studies evaluated total starch content and

crude fiber content that do not give a real picture of the nutritional implications of these

components (Vieira, 1967; Antunes, Bilhalva, Elias, & Soares, 1995; Castellón et al., 2003;

Lemos, Oliveira, Palomino, & Silva, 2004).

The objectives of the present study were: (i) to compare the physicochemical

characteristics of sixteen common bean cultivars; (ii) to investigate the persistence of the

nutrient profile along two harvests; and (iii) to assess the effect of storage conditions on

digestible starch, resistant starch, and dietary fiber contents of cooked beans. Results will be

useful for dietitians to choose the most appropriate cultivars for specific nutritional purposes

like public health programs (health policy) and strict dietary orientations.

2. Materials and methods

2.1. Samples

Common bean seeds (Phaseolus vulgaris L.) of sixteen cultivars (Carioca,

Diamante Negro, FTS Magnífico, FTS Soberano, Guapo Brilhante, Guateian 6662, IAPAR

31, Iraí, Macanudo, Minuano, Pérola, Rio Tibagi, TPS Bionobre, TPS Bonito, TPS Nobre,

and Valente) were obtained from the Department of Fitotecnia of the Federal University of

Santa Maria, Rio Grande do Sul, Brazil. They were grown during two consecutive years

(2001/2002 and 2002/2003) at the campus, which is placed at an altitude of 95 m. The local

climate, according to Köppen’s classification, is Cfa – subtropical, with total average annual

rainfalls and temperature around 1769 mm and 19.2°C, respectively. The soil is a typical

dystrophic red (Bandinelli et al., 2005). In both harvest years, seeds were grown under similar

field conditions and normal agronomic practices required for bean crops were followed. Each

cultivar was obtained from three independent lots of land, each one containing four rows (4 m

length and 50 cm row to row distance). After harvest, seeds from the three lots were pooled

and a representative sample (200 g) of each cultivar was taken and kept at –20°C in sealed

polyethylene bags until analysis.

2.2. Physical analysis

One thousand seed mass (g) was calculated as ten times the mass of 100 seeds. The

evaluation was performed in unbroken raw seeds chosen at random.

2.3. Chemical analysis

2.3.1. Raw bean analysis

Raw seeds (50 g) were finely ground into flour and kept at –20°C in sealed

polyethylene bags until analysis. Bean flours were analyzed as described by AOAC (1995) for

moisture (method 925.10), ash (method 923.03), fat (method 945.39), crude protein

(method 960.52, N x 6.25, microKjeldahl method), and crude fiber (method 962.09). Dry

matter and organic matter were calculated as 100 minus the centesimal content of moisture

and ash, respectively. Digestible and resistant starch were determined after enzymatic

hydrolysis according to the method no. 996.11 AOAC (1995, reviewed in 1998) as modified

by Walter (2005) that uses a higher amount of sample (300 mg instead of 100 mg), phosphate

buffer pH 6.8 instead of MOPS (4-morpholinepropanesulfonic acid) buffer pH 7.0, and

proteolysis during digestion process. Amylose value was determined by iodometric assay

(blue value; Gilbert & Spragg, 1964). Total and insoluble dietary fiber contents were

determined by enzymic-gravimetric methods no. 985.29 and no. 991.42 (AOAC, 1995) and

soluble dietary fiber content was calculated by difference. The enzymes employed for dietary

fiber and starch determination were: α-amylase (Termamyl 120L

), protease (Flavourzyme

and amyloglucosidase (AMG 300L

) supplied by Novozymes Latin América Ltda.

(Araucária, PR, Brazil). Activity and purity of the enzymes was controlled weekly in our

laboratory. For starch determination, glucose was measured using glucose-oxidase-peroxidase

test kit (Glucox 500) supplied by Doles (Goiânia, GO, Brazil). Calcium, iron, zinc, copper,

manganese, and magnesium were determined by atomic absorption spectroscopy (

Atomic

Absorption Spectrometer AA 12/1475 -

Intralab), and phosphorus content was determined

colorimetrically (Tedesco, Gianello, Bissani, Bohnen, & Volkweiss, 1995).

All experiments were conducted at least in duplicate. Duplicates falling within 10% of

their mean were accepted to be showing satisfactory agreement. The analysis was repeated if

the agreement was outside 10% of the mean for the duplicates, and then recalculated on the

basis of the concordant replicates. Reagent blanks were always run with samples and helped

to monitor the purity of the reagents used. Any significant value for the blank determination

was accounted for in the calculation of the results. Analytical quality control was monitored

through the use of in-house control and participation in the interlaboratory proficiency testing

scheme (INTERLAB) of the Science and Technology Foundation (CIENTEC, Porto Alegre,

RS, Brazil) that follows ISO and IUPAC guidelines for interlaboratory proficiency testing.

2.3.2. Cooked bean analysis

Based on raw seed analysis, four cultivars of high resistant starch content (FTS

Magnífico, IAPAR 31, Pérola, and TPS Bonito) and four cultivars of low resistant starch

content (Diamante Negro, Iraí, Macanudo, and Valente) were chosen in order to determine the

effect of storage conditions on starch and dietary fiber contents of cooked beans. Fifty grams

of bean seeds were soaked overnight in tap distilled water (250 ml) at room temperature.

Twelve hours later, they were cooked at 100°C with the soaking water in beakers covered by

an aluminum foil until they became suitable for consumption (approximately 40 min). The

cooked seeds were either immediately analyzed (control) or stored with the cooking water in

sealed containers at 4°C for 4 days or at –20°C for 28 days. At the moment of the analysis, the

seeds were drained off, dried on a paper towel, and ground into a paste.

Total, insoluble, and soluble dietary fiber, as well as the digestible and resistant starch

contents were determined in cooked beans according to the same methods described above.

Dry matter was determined after 48 h at 55°C in an assisted air circulation oven, followed by

8 h at 105°C. All experiments were conducted at least in duplicate.

2.4. Statistical analysis

For evaluation of year to year variability, data concerning physicochemical

characteristics from the two consecutive harvests were compared using the Student’s t-test for

paired samples (P<0.05) considering each cultivar sample as an independent replicate

(n=16). The correlations between the various physicochemical characteristics evaluated were

assessed by Pearson’s correlation in the whole population of cultivars studied (n=16)

separately in each harvest year.

Bean cultivars were divided into groups with distinctive chemical characteristics by

cluster analysis using the Ward’s method as indicated by Hair Jr, Anderson, Tahman, &

Black, 1998). This technique is a classification procedure that groups objects in clusters in

terms of their nearness or similarity for a set of variables. The measurement of the similarity

is based, among other ones, on the squared Euclidean distance. Data were standardized (Z

score) before cluster analysis in order to eliminate the bias introduced by the differences in the

scales of the several variables (chemical characteristics) used in the analysis. Since small

differences were observed in the physicochemical characteristics along the two harvests

evaluated, results from the two harvests were used as two independent replicates of each

cultivar in the cluster analysis. Comparisons among groups obtained by cluster analysis were

made separately for each chemical characteristic by one-way analysis of variance (ANOVA)

using untransformed values. The effect of storage conditions on the levels of digestible starch,

resistant starch, total dietary fiber, insoluble dietary fiber, and soluble dietary fiber of cooked

beans were evaluated using two-way ANOVA (2 types of sample x 3 storage conditions, with

4 independent replicates per group). Post-hoc analysis was carried out using Duncan’s test

(P<0.05). The software used for the analysis was SPSS 8.0 for Windows.

3. Results and discussion

3.1. Influence of harvest year on physicochemical characteristics of bean cultivars

Seed characteristics are determined by cultivar genotype and environmental

conditions during plant growth and seed development. Table 1 shows the average

physicochemical characteristics of the sixteen bean cultivars along two consecutive harvests

(2001/2002 and 2002/2003). Of the sixteen bean cultivars evaluated only Carioca, Iraí, and

Pérola had been previously studied concerning some physicochemical characteristics before

and after cooking procedure (Universidade de São Paulo, 2005). The average values were

similar to those reported for other common bean cultivars (Vieira, 1967; Barampama et al,

1993; Antunes et al., 1995; Universidade de São Paulo, 2005). Most physicochemical

characteristics evaluated concerning macro and micronutrients contents did not change

significantly throughout the harvests, except for the slight moisture decrease (P<0.05), and

dry matter and total dietary fiber increase (P<0.05; Table 1) from the first to the second

harvest. On average, these results indicate that the various cultivars exhibited a constant

profile for most nutrients along the two harvests.

Although no major differences were observed in the average chemical characteristics

of seeds between the two harvests, remarkable ranges were observed in physical (1000 seeds

mass) and chemical characteristics (ash, crude protein, crude fiber, dietary fiber, crude fat,

amylose, and starch content) within each harvest (Table 1). Common beans are important

dietary sources of protein, starch, and fiber. Therefore, the range in the content of protein

(36%), insoluble dietary fiber (70%), soluble dietary fiber (106%), digestible starch (77%),

and resistant starch (100%) could be used to categorize bean cultivars according to their

nutritional potential.

We assessed the correlations between the various physicochemical characteristics

shown in Table 1. Similar to the results of Lemos et al. (2004) we also found a significant

negative correlation between protein (PROT) and 1000 seed mass (r = -0.65 for harvest 1 and

-0.55 for harvest 2), indicating that bigger seeds have lower PROT contents. An interesting

finding is that crude fiber had no significant correlation with total, soluble or insoluble dietary

fiber, which indicates that crude fiber assay is unsuitable to estimate the fiber content of bean.

3.2. Categorizing bean cultivars according to their macronutrient content

Previous studies discuss separately the variation of each nutrient among bean

cultivars. However, this approach provides an incomplete analysis of the nutritional potential

of different cultivars. Therefore, in the present study we used the multivariate cluster analysis

to classify the set of cultivars into groups of different nutritional quality based on their

similarities for a set of characteristics. Table 2 shows characteristics of groups formed by

multivariate cluster analysis based on their similarity for the content of some macronutrients

measured along two consecutive harvests (crude protein-PROT, total dietary fiber-TDF,

insoluble dietary fiber-IDF, soluble dietary fiber-SDF, digestible starch-DS, and resistant

starch-RS). These nutrients were chosen based on the relevance of common beans intake as a

dietary source. According to cluster analysis cultivars were divided into four groups (Table 2).

Group A that was formed by cultivars TPS Bonito, Iraí, and Minuano had low PROT, high

TDF, IDF, DS, and RS, and intermediate levels of SDF. Group B (Carioca, FTS Magnífico,

FTS Soberano, Guapo Brilhante, IAPAR 31, Pérola, TPS Bionobre, and TPS Nobre) had

intermediate levels of PROT and IDF, low levels of TDF and SDF, but high levels of DS and

RS. Group C (Diamante Negro, Macanudo, and Valente) also had intermediate PROT and

IDF levels, and low TDF and SDF, but in contrast to group B, group C had low levels of DS

and RS. Group D (Guateian 6662 and Rio Tibagi) had the highest PROT and SDF levels, high

DS levels, low TDF and IDF, and intermediate RS levels.

It is known that we can have different biological effects depending on the levels of

nutrients in the diet. The present data shows that the genetic variability among bean cultivars

significantly influenced its chemical characteristics. Among these cultivars those that

exhibited an interesting nutritional profile could be selected for specific dietary purposes, for

example, cultivars from group D (high PROT and DS levels) could be used for undernutrition

prevention. Some macronutrients like TDF, IDF, SDF and RS have been demonstrated to

reduce serum lipid levels, and regulate blood insulin and glucose levels (Guillon & Champ,

2002; Higgins, 2004). Hence, cultivars from groups A (high TDF and IDF, intermediate SDF,

and high RS) and D (high SDF) could be indicated for reduction of the risk of colon cancer

and coronary disease, as well as for the prevention of diseases related to insulin resistance

(Guillon & Champ, 2002; Lupton & Turner, 2003).

3.3. Categorizing bean cultivars according to their micronutrient content

The great range observed in the ash content (70%) of bean cultivars (Table 1) suggests

that the content of some essential minerals may vary significantly among the studied cultivars.

Since common beans are an important source of iron and other minerals these micronutrients

were also determined in the common beans evaluated (Table 3). According to the literature

common beans exhibit a great range in the content of minerals (mg/100g dry weight basis)

like Fe (2–18), Zn (1–7), Mn (1–2), Cu (0.20–1.96), Ca (55–284), Mg (38–369), and P (295–

570) (Augustin et al., 1981; Barampama & Simard, 1993; Vazquez-Blanco, Vazquez-Oderiz,

Simal-Lozano & Lopez-Hernandez, 1997; Samman et al., 1999; Nunez-Gonzalez et al.,

2002). In this study, Fe, Zn, Mn, Cu, Ca, and P contents were similar to those found in

literature (Table 3). However, Mg content was slightly lower than previously reported values.

Considering the nutritional importance of beans as mineral source, cultivars

evaluated in the present study were also classified based on their similarity for the content of

some micronutrients along two consecutive harvests (Table 3). Bean cultivars were divided

into four different groups. No significant differences were observed in P content among the

groups formed. Group A that was formed by cultivars Iapar 31, Iraí, and Macanudo had low

levels of all minerals evaluated (Fe, Zn, Mn, Cu, Mg) with the exception of Ca that was found

at intermediate levels in this group. Group B (Carioca, Guapo Brilhante, Minuano) had low

levels of Zn and Mn, intermediate levels of Fe, and high levels of Cu, Ca, and Mg. Group C

(Diamante Negro, TPS Bonito, Valente) had low levels of Ca, intermediate levels of Mn and

Mg, and high levels of Fe, Zn, and Cu. Group D (FTS Magnífico, FTS Soberano, Guateian

6662, Pérola, Rio Tibagi, TPS Bionobre, TPS Nobre) had the highest content for all minerals

evaluated.

Changes in mineral profile of beans can be explained by a variety of factors, including

genotypic variability in absorption of minerals from soil (Nunez-Gonzalez et al., 2001), effect

of fertilizers on metallic composition of plants (Sadiq & Hussain, 1994), and salinity levels of

soil (Carbonell-Barrachina, Burlo, & Mataix, 1998). In this study, the soil used for seeding

and the fertilization practices were kept the same for all cultivars. Hence, the differences of

mineral profile among the cultivars could be attributed to genotypic variability.

As observed for macronutrients, these changes in mineral levels have an important

role in human nutrition, because different cultivars could be used for specific nutritional

purposes as mineral deficiencies. Based on Table 3 we can select cultivars with the highest

levels of Fe, Zn, (groups C and D), and Ca (groups B and D) for the prevention of these

ordinary mineral deficiencies. The data presented here can also be useful for selecting

cultivars for the development of new ones, with a more appropriate nutritional profile for

populations with specific mineral dietary deficiencies.

3.4. Effect of storage conditions on cooked beans

The effect of storage conditions on DS and RS contents of cooked beans were

evaluated using cultivars that had either low or high RS levels before cooking (Fig. 1). DS

content of cooked beans significantly reduced after storage at 4°C both for low and high RS

cultivars. However, storage at -20°C only reduced DS content of low RS cultivars (Fig. 1A).

RS content of both low and high RS cultivars was significantly increased after storage of

cooked beans at 4

C, but at -20

C only low RS cultivars had a significant increase in RS

content (Fig. 1B). It is noteworthy that the increase in RS content during storage was much

more pronounced for low than for high RS cultivars, in such a way that the RS profile of

cultivars was inverted after storage at -20

C (Fig. 1B). These results suggest that beans that

have low RS content before cooking are more prone to retrogradation after cooking. Hence,

we can propose that the behavior of bean starch during storage may vary among different

cultivars. This observation may help to explain previous controversial results on the effects of

cooking and storage conditions on starch levels of common beans. Some authors found a

decrease of digestible starch and increase of resistant starch after storage at 4°C (Vargas-

Torres et al., 2004), others found no changes (Landa-Habana et al., 2004), and others found an

increase of digestible starch (Osorio-Diaz, Bello-Perez, Sayago-Ayerdi, Benitez-Reyes,

Tovar, & Paredes-Lopez, 2003).

The effects of storage conditions on TDF, IDF, and SDF contents of cooked beans

were also evaluated using cultivars that had either low or high RS levels before cooking (Fig.

2). TDF (Fig. 2A), IDF (Fig. 2B), and SDF (Fig. 2C) contents of cooked beans did not

change during storage.

Previous studies on the dietary fiber of common beans focused on the effects of

cooking and revealed variable results, since either increase or decrease of TDF, IDF, and SDF

was observed by different authors (Hughes & Swanson, 1989; Kutos et al., 2003). No study

was found on the effects of different storage conditions on dietary fiber (DF) levels of

common beans. In the present study we demonstrated that DF content did not change during

storage of cooked beans. RS is a component of IDF, and it did change during storage (Fig. 1).

However, no change was observed in IDF fraction, probably because RS contributes to a

small part of this fraction in cooked beans (10-20%).

4. Conclusions

It was possible to identify groups of cultivars with different nutritional features.

Guateian 6662 and Rio Tibagi appeared to be the most adequate cultivars to prevent

nutritional deficiencies, because they had high PROT, DS, Fe, and Zn content. Cultivars with

a composition more adequate for prevention of coronary disease and diseases related to

insulin resistance (Iraí, Minuano, and TPS Bonito) were also identified. The observed

variability among bean cultivars reveal the need for bringing food composition tables up to

date by including an expected range of nutrients for each cultivar.

Besides, it was shown that the increase in RS content and the decrease in DS during

storage of cooked beans were higher for beans that had low RS content before cooking. The

TDF, IDF and SDF contents did not change. These results may be useful in selecting cultivars

for breeding and for specific uses in human nutrition.

Acknowledgements

Authors thank to Novozymes Latin American Ltda. for kindly donation of enzymes

and Doles (GO, Brazil) for donation of GOP test kit. T. Emanuelli is the recipient of a CNPq

research fellowship. L.P. Silva is the recipient of CAPES/PRODOC fellowship.

References

Antunes, P.L., Bilhalva, A.B., Elias, M.C. , & Soares, G.J.D. (1995). Valor nutricional de

feijão (Phaseolus vulgaris L.), cultivares Rico 23, Carioca, Piratã-1 e Rosinha-G2. Revista

Brasileira de Agrociência, 1, 12-18.

AOAC. (1995). Official Methods of Analysis of the Association of the Official Analysis

Chemists (16

ed.). Arlington, VA: Association of Official Analytical Chemists.

Augustin, J., Beck, C.B., Kalbfleish, G., Kagal, L.C., & Mathews, R.H. (1981). Variation in

the vitamin and mineral content of raw and cooked commercial Phaseolus vulgaris classes.

Journal of Food Science, 46, 1701-1706.

Bandinelli, D.G., Gatiboni, L.C., Trindade, J.P.P, Quadros, F.L.F., Kaminski, J., Flores, P.C.,

Brunetto, G., & Saggin, A. (2005). Botanical composition of natural pasture as affected by

phosphorus sources, lime and introduction of winter forage species. Ciência Rural, 35, 84-

91.

Barampama, Z., & Simard, R.E. (1993). Nutrient composition, protein quality and

antinutritional factors of some varieties of dry beans (Phaseolus vulgaris) grown in

Burundi. Food Chemistry, 47, 159-167.

Carbonell-Barrachina, A.A., Burlo, F., & Mataix, J. (1998). Response of bean micronutrient

nutrition to arsenic and salinity. Journal of Plant Nutrition, 21, 287-299.

Castellón, R.E.R., Araújo, F.M.M.C., Ramos, M.V., Andrade Neto, M., Freire Filho, F.R.,

Grangeiro, T.B., & Cavada, B.S. (2003). Composição elementar e caracterização da fração

lipídica de seis cultivares de caupi. Revista Brasileira de Engenharia Agrícola e

Ambiental, 7, 149-153.

Gilbert, G.A., & Spragg, S.P. (1964). Iodine sorption: “blue value”. In R. L. Whistler,

Methods in Carbohydrate Chemistry, vol. IV, Starch (pp. 168-169). New York: Academic

Press.

Guillon, F., & Champ, M. M. (2002). Carbohydrate fractions of legumes: uses in human

nutrition and potential for health. British Journal of Nutrition, 88 (suppl. 3), S293-306.

Hair Jr, J.F., Anderson, R.E., Tahman, R.L., & Black, W.C. (1998). Multivariate data

analysis. New Jersey: Prentice-Hall Inc.

Higgins, J.A. (2004). Resistant starch: metabolic effects and potential health benefits. Journal

of AOAC International, 87, 761-768.

Hughes, J.S., & Swanson, B.G. (1989). Soluble and insoluble dietary fiber in cooked common

bean (Phaseolus vulgaris L.) seeds. Food Microstructure, 8, 15-21.

Kigel, J. (1999). Culinary and nutritional quality of Phaseolus vulgaris seeds as affected by

environmental factors. Biotechnology, Agronomy, Society and Environment, 3, 205-209.

Kutos, T., Golob, T., Kač, M., & Plestenjak, A. (2003). Dietary fiber content of dry and

processed beans. Food Chemistry, 80, 231-235.

Landa-Habana, L., Piña-Hernández, A., Ágama-Acevedo, E., Tovar, J., & Bello-Pérez, L.A.

(2004). Effect of cooking procedures and storage on starch bioavailability in common

beans (Phaseolus vulgaris L.). Plant Foods for Human Nutition, 59, 133-136.

Lemos, L.B., Oliveira, R.S., Palomino, E.C., & Silva, T.R.B. (2004). Características

agronômicas e tecnológicas de genótipos de feijão do grupo comercial Carioca. Pesquisa

Agropecuária Brasileira, 39, 319-326.

Lupton, J.R., & Turner, N.D. (2003). Dietary fiber and coronary disease: does the evidence

support an association? Current Atherosclerose Reports, 5, 500-505.

Nunez-Gonzalez, M.A., Maiti, R.K., Verde, J., Foroughbakch, R., Garcia-Diaz, G., Martinez-

Lozano, S., Heredia-Rojas, N.L., Moreno-Limon, S., Hernandez-Pinero, J.L., & Cardenas-

Avila, M.L. (2001). Genotypic variability in absorption of minerals among bean

(Phaseolus vulgaris L.) cultivars exposed to low nutrient stress. Crop Research, 22, 408-

423.

Nunez-Gonzalez, M.A., Maiti, R.K., Verde, J., Cardenas-Avilla, M.L., Foroughbakch, R.,

Hernandez-Pinero, J.L., Moreno-Limon, S., & Garcia-Diaz, G. (2002). Variability in

mineral profile in seven varieties of bean (Phaseolus vulgaris L.) adapted in North East of

Mexico. Legume Research, 25, 284-287.

Osorio-Diaz, P., Bello-Perez, L.A., Sayago-Ayerdi, S.G., Benitez-Reyes, M.Del P., Tovar, J.,

& Paredes-Lopez, O. (2003). Effect of processing and storage time on in vitro digestibility

and resistant starch content of two bean (Phaseolus vulgaris L.) varieties. Journal of

Science and Food Agricultural, 83, 1283-1288.

Sadiq, M., & Hussain, G. (1994). Effect of chelate fertilizers on dry matter and metallic

composition of bean plants in a pot experiment. Journal of Plant Nutrition, 17, 1477-1488.

Samman, N., Maldonado, S., Alfaro, M.E., Farfan, N., & Gutierrez, J. (1999). Composition of

different bean varieties (Phaseolus vulgaris) of northwestern Argentina (region NOA):

cultivation zone influence. Journal of Agricultural and Food Chemistry, 47, 2685-2689.

Silva, L.P. da (2002). Composição Química de Trigo e de Aveia e Efeito dos Teores e

Proporções de Fibra Alimentar sobre a Resposta Biológica de Frangos de Corte e Ratos.

Tese (Doutorado em Zootecnia), Faculdade de Agronomia, Universidade Federal do Rio

Grande do Sul, Brasil.

Storck, C.R., Silva, L.P. da, & Fagundes, C.A.A. (2005). Categorizing rice cultivars based on

differences in chemical composition. Journal of Food Composition and Analysis, 18, 333-

341.

Tharanathan, R.N., & Mahadevamma, S. (2003). Grain legumes – a boon to human nutrition.

Trends in Food Science & Technology, 14, 507-518.

Tedesco, M.J., Gianello, C., Bissani, C.A., Bohnen, H., & Volkweiss, S.J. (1995). Análise de

Solo, Plantas e Outros Materiais. (Boletim Técnico, n.5) 2. ed. Departamento de Solos,

UFRGS, Porto Alegre.

The Michigan Bean Commission (2006). Beans and inhibition of cancer. Retrieved 2006-03-

03: http://www.michiganbean.org/research.html.

Universidade de São Paulo (2005). Faculdade de Ciências Farmacêuticas. Departamento de

Alimentos e Nutrição Experimental / BRASILFOODS. Tabela Brasileira de Composição

de Alimentos-USP. Versão 4.1. Retrieved 2005-10-05: http://www.fcf.usp.br/tabela.

Vargas-Torres, A., Osorio-Diaz, P., Islas-Hernández, J.J., Tovar, J., Paredes-Lopéz, O., &

Bello-Pérez, L.A. (2004). Starch digestibility of five cooked black bean (Phaseolus

vulgaris L.) varieties. Journal of Food Composition and Analysis, 17, 605-612.

Vazquez-Blanco, M.E., Vazquez-Oderiz, M.L. Simal-Lozano, J., & Lopez-Hernandez, J.

(1997). Determination of mineral elements in Galician green beans by atomic

spectroscopy. Deutsche Lebensmittel-Rundschau, 93, 286-287.

Vieira, C. (1967). O Feijoeiro-Comum: Cultura, Doenças e Melhoramento. Viçosa, MG:

Universidade Federal de Viçosa.

Walter, M. (2005). Amido Resistente: Metodologias de Quantificação e Resposta Biológica

em Ratos. Dissertação (Mestrado em Ciência e Tecnologia de Alimentos), Universidade

Federal de Santa Maria, Santa Maria, Brasil.

Figure captions

Fig. 1. Effect of storage on digestible (A) and resistant (B) starch content of cooked common

beans that had either a low (open bars) or a high (hatched bars) resistant starch content before

cooking. Results (g/100 g of dry weight) are mean±standard error (n=4). Bars within the same

panel that have no common letters are significantly different (P<0.05).

Fig. 2. Effect of storage on total dietary fiber (A), insoluble fiber (B), and soluble fiber (C) of

cooked common beans that had either a low (open bars) or a high (hatched bars) resistant

starch content before cooking. Results (g/100 g of dry weight) are mean±standard error (n=4).

Table 1

Physicochemical characteristics of common bean seeds from 2 consecutive harvests

(2001/2002 and 2002/2003)

Characteristics 1

(2001/2002)

(2002/2003)

1000 seed mass (g) 223.19±9.74

(165.00-331.70)

230.59±10.48

(158.40-338.60)

Dry matter

(g/100 g fresh weight)

86.67± 0.13

(85.92-87.57)

87.09±0.12*

(86.09-87.79)

Organic matter

(g/100 g fresh weight)

96.12±0.12

(95.50-97.07)

96.16±0.14

(95.46-97.33)

Moisture

(g/100 g fresh weight)

13.33±0.13

(12.43-14.08)

12.91±0.12*

(12.21-13.91)

Ash

(g/100 g fresh weight)

3.90±0.12

(2.93-4.50)

3.84±0.14

(2.67-4.54)

Crude protein

(g/100 g dry weight)

25.69±0.55

(21.24-29.06)

25.11±0.41

(22.50-27.96)

Crude fiber

(g/100 g dry weight)

4.79±0.17

(3.64-5.72)

4.98±0.18

(3.54-6.05)

Total dietary fiber

(g/100 g dry weight)

23.97±0.54

(20.79-28.79)

25.35±0.72*

(21.02-31.91)

Insoluble dietary fiber

(g/100 g dry weight)

18.81±0.65

(13.80-23.49)

19.50±0.50

(16.97-22.79)

Soluble dietary fiber

(g/100 g dry weight)

5.17±0.48

(3.59-10.68)

5.90±0.60

(1.44-9.72)

Crude fat

(g/100 g dry weight)

1.90±0.25

(0.98-5.49)

1.82±0.21

(0.92-4.43)

Amylose

(g/100 g dry weight)

8.35±0.28

(6.16-10.08)

9.02±0.21

(7.54-10.34)

Digestible starch

(g/100 g dry weight)

29.40±1.15

(20.02-35.61)

30.81±1.12

(23.66-39.41)

Resistant starch

(g/100 g dry weight)

3.34±0.18

(2.35-4.70)

3.44±0.17

(2.46-4.58)

Results are expressed as mean value±standard error (min-max) of sixteen bean cultivars.

*Significantly different from harvest 2001/2002 (P< 0.05, Student’s t-test).

Table 2

Groups formed by bean cultivars considering the levels of macronutrients*

Group/Cultivars PROT TDF IDF SDF DS RS

A: Iraí; Minuano; TPS Bonito

22.93

↓

(0.67)

28.83

↑

(0.18)

22.31

↑

(0.22)

6.51

a,b

↕

(0.36)

31.73

↑

(0.85)

3.81

↑

(0.40)

B: Carioca; FTS Magnífico; FTS Soberano; Guapo

Brilhante; Iapar 31; Pérola; TPS Bionobre; TPS Nobre

25.61

↕

(0.41)

23.96

↓

(0.38)

19.23

↕

(0.46)

4.72

↓

(0.44)

31.54

↑

(1.40)

3.60

↑

(0.19)

C: Diamante Negro; Macanudo; Valente

25.59

↕

(0.85)

22.71

↓

(0.50)

17.84

b,c

↕

(0.57)

4.87

↓

(0.57)

24.29

↓

(1.68)

2.50

↓

(0.02)

D: Guateian 6662; Rio Tibagi

27.96

↑

(0.26)

24.15

↓

(0.28)

16.04

↓

(0.64)

8.11

↑

(0.92)

30.60

↑

(3.02)

3.24

a,b

↕

(0.30)

*Results (g/100 g of dry weight) are mean (standard error) of the group of cultivars indicated in the first column, each one analyzed in two

harvests (2001/2002 and 2002/2003). Values within the same column that have no common superscript are significantly different (P< 0.05,

Duncan’s test). PROT: crude protein; TDF: total dietary fiber; IDF: insoluble dietary fiber; SDF: soluble dietary fiber; DS: digestible starch; RS:

resistant starch. ↑, ↕, and ↓ indicate high, intermediate, and low levels of each macronutrient.

Table 3

Groups formed by bean cultivars considering the levels of micronutrients*

Group / Cultivars Fe Zn Mn Cu Ca Mg P

A: Iapar 31; Iraí; Macanudo

8.26

↓

(0.33)

3.18

↓

(0.08)

1.35

↓

(0.05)

1.10

↓

(0.12)

257.23

↕

(46.09)

21.53

↓

(1.17)

358.59

(11.12)

B: Carioca; Guapo Brilhante; Minuano

9.08

↕

(0.15)

3.20

↓

(0.09)

1.44

↓

(0.02)

1.39

↑

(0.06)

373.23

↑

(22.15)

23.88

↑

(0.45)

351.17

(14.17)

C: Diamante Negro; TPS Bonito; Valente

9.26

a,b

↑

(0.11)

3.57

↑

(0.05)

1.53

a,b

↕

(0.04)

1.44

↑

(0.03)

147.01

↓

(15.32)

23.19

a,b

↕

(0.17)

335.69

(15.14)

D: FTS Magnífico; FTS Soberano; Guateian 6662;

Pérola; Rio Tibagi; TPS Bionobre; TPS Nobre

9.65

↑

(0.11)

3.53

↑

(0.09)

1.67

↑

(0.05)

1.55

↑

(0.05)

399.75

↑

(11.57)

24.64

↑

(0.38)

342.47

(9.61)

*Results (mg/100g of dry weight) are mean (standard error) of the group of cultivars indicated in the first column, each one analyzed in two

harvests (2001/2002 and 2002/2003). Values within the same column that have no common superscript are significantly different (P< 0.05,

Duncan’s test); ns: not significant. ↑, ↕, and ↓ indicate high, intermediate, and low levels of each micronutrient

Fig. 1

control 4°C -20°C

Storage conditions

Digestible starch

control 4°C -20°C

Storage conditions

Resistant starch

c,d

a,b

b,c

Fig. 2

control 4°C -20°C

Storage conditions

Total fiber

control 4°C -20°C

Storage conditions

Insoluble fiber

control 4°C -20°C

Storage conditions

Soluble fiber

3.2 Manuscrito 2

EFFECTS OF COMMON BEAN (Phaseolus vulgaris L.) DIETS ON SERUM

LIPIDS AND BLOOD GLUCOSE LEVELS IN NORMOLIPIDEMIC-

NORMOGLYCAEMIC RATS

Manuscrito em fase final de revisão pelos autores para ser submetido à revista

BRITISH JOURNAL OF NUTRITION

Effects of common bean (Phaseolus vulgaris L.) diets on serum lipids and

blood glucose levels in normolipidemic-normoglycaemic rats

Ivo Roberto Dornelles Prolla

1,2

, Roberta Garcia Barbosa

, Carina Mota

, Bruna Gaelzer Silva

Torres

, Leila Picolli da Silva

and Tatiana Emanuelli

1,*

Núcleo Integrado de Desenvolvimento em Análises Laboratoriais (NIDAL), Departamento

de Tecnologia e Ciência dos Alimentos, Centro de Ciências Rurais, Universidade Federal de

Santa Maria, Camobi, 97105-900, Santa Maria, RS, Brasil.

Departamento de Pediatria e Puericultura, Centro de Ciências da Saúde, Universidade

Federal de Santa Maria, Camobi, 97105-900, Santa Maria, RS, Brasil.

Departamento de Zootecnia, Centro de Ciências Rurais, Universidade Federal de Santa

Maria, Camobi, 97105-900, Santa Maria, RS, Brasil.

* Corresponding author. Tel.: +55 55 3220 8547; fax: +55 55 3220 8353.

E-mail address: tatiem[email protected] (T. Emanuelli).

Corresponding author:

Tatiana Emanuelli

Núcleo Integrado de Desenvolvimento de Análises Laboratoriais (NIDAL)

Departamento de Tecnologia e Ciência dos Alimentos

Centro de Ciências Rurais

Universidade Federal de Santa Maria

Campus – Camobi, 97105-900

Santa Maria, RS - Brasil

Telephone: +55 55 3220 8547

Fax: +55 55 3220 8353

E-mail:

tatiemanuelli@smail.ufsm.br

Running title: Effect of beans on blood lipids and glucose

Abstract

Common beans (Phaseolus vulgaris L.) have different soluble fibre/total fibre ratios (SF/TF)

according to the genetic variety. This study was aimed at determining the effects of three

cultivars of common beans containing different SF/TF (Pérola diet, 0·11; Diamante Negro

diet, 0·19; Iraí diet, 0·25) on serum lipids, blood glucose and others biological parameters in

normolipidemic-normoglycaemic rats. Male Wistar rats (52·0±1·1 g) were fed isocaloric and

isonitrogenous diets with 5% fibre content obtained from one of the three bean cultivars or

from cellulose (100% insoluble fibre - Control) during an experimental period of 23 days. No

differences were observed in food intake or body weight among groups. Animals fed Iraí diet

had significantly higher food efficiency ratio (0·33 g/g) when compared to Diamante Negro

and control (0·30 and 0·31 g/g, respectively), while those fed with Pérola diet had

intermediate values (0·32 g/g). Iraí had higher dry matter, starch, and fibre digestibility (92·6,

94·6, and 86·8%, respectively) than the other bean diets (90·3-90·5, 91·9-92·3, and 77·1-

79·5%; P<0·05). All bean diets lead to higher faecal weight and faecal moisture

(Pérola>Diamante Negro>Iraí), and lower faecal pH (Pérola<Diamante Negro<Iraí) than

control (P<0·05). All bean diets lead to lower epididymal fat weight and total blood

cholesterol levels than control diet (P<0·05). Fibre digestibility was negatively correlated to

cholesterol levels (r=-0·84) and epididymal fat weight (r= -0·58; P<0·05). The glycaemic peak

occurred at 30 min for animals fed bean diets and at 60 min for those fed control diet

(P<0·05). Besides, animals fed bean diets had lower total area under the glycaemic curve than

control animals (P<0·05). We concluded that diets with cultivars of common beans containing

higher SF/TF reduce serum cholesterol, blood glucose levels and fat retention in

normolipidemic-normoglycaemic rats.

Keywords: digestibility; cholesterol; glycaemic curve; insoluble fibre; soluble fibre; faecal

pH, epididymal fat.

1. Introduction

Common beans (Phaseolus vulgaris L.) are widely consumed throughout the world,

mainly by low income populations. In addition to the nutritional properties, it is known that

they have potential benefits on human health. Beans have been responsible for an important

lowering effect on serum lipids (Fukushima et al. 2001). In hyperlipidemic subjects, bean

water-soluble fibre was shown to decrease total cholesterol (13 to 26%), HDL cholesterol (5

to 20%) and triglyceride levels (3 to 25%) (Anderson & Gustafson, 1988). Although some

authors have related the lipid-lowering effect to the starch fraction, presumably on its saponin

content (Amígo et al. 1992), the soluble fibre seams to be really the active portion of the

legume (Aller et al. 2004).

This legume has also a lowering effect on plasma glucose (Pari & Venkateswaran,

2003). This property has been related not only to starch digestibility, but also to fibre contents

(Panlasigui et al. 1995). The fibre fraction seems to lower blood glucose responses due to a

delaying in gastric emptying and due to a reduction in the rate of nutrient absorption from

gastrointestinal tract (Thorne et al. 1983; Bjorck & Elmstahl, 2003). The blood glucose

response can be expressed either as the area under the glycaemic curve or as the glycaemic

index. High glycaemic index diets are associated with higher insulin response and increased

risk of obesity (Pawlak et al. 2001). Common beans are considered a low glycaemic index

food.

It is known that bean grains are excellent sources of dietary fibre, providing a mix

of soluble and insoluble fibres (Messina, 1999) with all the remarkable effects already related

to them. However, common bean cultivars have significant differences in chemical

composition, including the fibre content. Thus, their properties can be also quite different.

The majority of the studies concerning the effects of common bean-based diets were

performed in hypercholesterolemic (Dabai et al. 1996; Rosa et al. 1998 a; 1998 b) or

hyperglycaemic rats (Pari & Venkateswaran, 2003). In these models, bean consumption

improved lipids and glucose levels. However, studies on its effects in healthy animals are still

lacking (Amigo et al. 1992). Besides, we did not find any study comparing the effect of bean

cultivars with different levels of soluble fiber content on these parameters.

Therefore, this study was aimed at evaluating the effects of three cultivars of common

beans containing different proportions of water-soluble fibre (Pérola: 11%; Diamante Negro:

19%; and Iraí: 25% of total dietary fibre levels, respectively) on serum lipids, blood glucose

and other biological parameters in normolipidemic-normoglycaemic rats.

2. Materials and methods

2.1. Bean flour

Common bean (Phaseolus vulgaris L.) grains of three cultivars (Pérola, Diamante Negro and

Iraí) were provided by Centro Nacional de Pesquisa de Arroz e Feijão – EMBRAPA (Santo

Antônio de Goiás, Goiás, Brazil) and had been grown during the harvest year 2005.

Five kg of each bean grains were soaked overnight in tap water (1:3 wt/wt ratio) at

room temperature. Twelve hours later, they were cooked separately at 100°C with the soaking

water in covered pots until they became suitable for consumption (approximately 90 min).

The cooked grains were drained off, dried at 55°C in an assisted air circulation oven for 48

h and ground into fine flour, which was used for chemical analysis and for diet formulation.

2.2. Bean flour analysis

Bean flours were analyzed as described by AOAC (1995) for moisture (method 925.10), ash

(method 923.03), fat (method 945.39), and crude protein (method 960.52, N x 6·25,

microKjeldahl method). Dry matter was determined after 48 h at 55°C in an assisted air

circulation oven, followed by 8 h at 105°C. Digestible starch was determined after enzymatic

hydrolysis according to the method no. 996.11 (AOAC, 1995, reviewed in 1998) as modified

by Walter (2005) that uses a higher amount of sample (300 mg instead of 100 mg), phosphate

buffer pH 6·8 instead of MOPS (4-morpholinepropanesulfonic acid) buffer pH 7·0, and

proteolysis during digestion process. Total and insoluble dietary fibre contents were

determined by enzymic-gravimetric methods no. 985.29 and no. 991.42 (AOAC, 1995) and

soluble dietary fibre content was calculated by difference. All the enzymes used in chemical

analysis, Termamyl 120L

(amylase), AMG 200

(amyloglycosidase) and Alcalase 2

(protease), were provided by Novozymes Latin America Ltda.

2.3. Animal experiment

This study was approved by the Ethics and Animal Welfare Committee of Universidade

Federal de Santa Maria. Thirty-two male weanling Wistar rats (52·0±1·1 g) were randomly

assigned into four dietary groups (8 animals each) and individually housed in cages placed in

a room with controlled temperature (22±1°C), humidity (65±5%) and light (12-h light and 12-

h dark periods). One group was fed a control diet (C-diet), according to AIN-93 rodent diet

(Reeves et al. 1993), containing 5% fibre from crystalline cellulose (100% insoluble fibre).

The other three groups were fed experimental diets similar to AIN-93, except for the source

and type of fibre. Each experimental diet was formulated with the bean flour of one cultivar:

Pérola diet (P-diet), Diamante Negro diet (DN-diet), and Iraí diet (I-diet) (Table 1). The

amount of flour was that to ensure the same percentage of total fibre present in C-diet (5%)

(Tables 1 and 2). Protein and starch content of experimental diets were balanced in order to

match the same levels found in AIN-93. All diets had the same amount of sucrose, soybean

oil, mineral mix, vitamin mix, choline and methionine, ensuring isoproteic and isocaloric

diets.

Rats were provided tap water and food ad libitum during the whole experiment. A

period of 5 days was allowed for adaptation to the diets, followed by a 23-day experimental

period with daily feed intake and weight gain record. On each day of the experimental period,

faeces and spilled food for each rat were collected. The faeces were weighed and stored in

plastic containers at 4°C until analysis. The spilled food were weighed and discharged.

Blood glucose levels were evaluated from the 17-day to the 20-day of the experimental

period, using 8 randomly chosen animals in each day. After a 12 h fasting period, 2 µl blood

was extracted from the tail of the animal and glucose concentration was immediately

determined (time 0). Then, the rats were allowed to eat 2 g of their respective diets (control or

experimental diets). After 20 minutes the pots of food were removed from the cages and new

blood glucose determinations were performed at 15, 30, 45, 60 and 90 minutes later.

At the 23-day of the experimental period animals were fasted during 12 h and

submitted to euthanasia by cardiac puncture under ether anesthesia. The blood was collected

in a 5-ml tube and serum was obtained after centrifugation. Liver and epididymal fat pad were

removed and weighed.

2.4. Faecal analysis

Dry matter, moisture, total dietary fibre and starch were analyzed following to the

same methods described for bean flour. pH was evaluated directly in a solution made of 1 g of

faeces and 10 ml of distilled water.

2.5. Blood analysis

Serum triglycerides, total cholesterol and HDL (high-density-lipoprotein) cholesterol were

measured enzymatically using laboratory kits (Triglicérides 120, Colesterol 250 and

Colesterol HDL, supplied by Doles Reagentes, Goiânia, GO, Brazil).

Blood glucose was assessed in blood samples extracted from the tail of the animal

with reactive strips read in a portable glucosemeter (ACCU-CHEK

Advantage blood glucose

meter). We determined the area under the curve (AUC) for each animal using the Data Master

Program 2003, version 11·7. Total AUC was defined by the area under the 90 minutes blood

glucose response curve following the ingestion of 2 g portion of the respective diet. We also

calculated partial AUC for each period of time along the curve. The AUC of the testing food

was divided by the AUC of the control diet and multiplied by 100. Thus, AUC for the control

diet was expressed as 100, while for the experimental diets it was a percentage of this value

(Thorne et al. 1983).

2.6. Statistical analysis

Results are presented as the mean ± standard error of the mean. Data were analysed by one-

way analysis of variance (ANOVA). Data of glycaemic curve was analysed by ANOVA with

time considered as repeated measure. Post-hoc analysis was carried out using Duncan’s test

(P<0·05). The software used for the analysis was SPSS 8·0 for Windows.

3. Results and discussion

Male Wistar rats were fed isocaloric and isoproteic diets with 5% fibre content

obtained from one of three bean cultivars or from cellulose (100% insoluble fibre - Control)

during the whole experimental period (23 days). The only difference among diets was the

soluble fibre/total fibre ratio (Table 2). Control (C-diet) and experimental diets (Pérola diet, P-

diet; Diamante Negro diet, DN-diet; and Iraí diet, I-diet) were well tolerated by all animals.

Final body weight, feed intake, and weight gain were similar among all groups (Table 3).

C-diet and I-diet groups showed higher dry matter and starch digestibility than DN-

diet and P-diet groups (Table 4). The highest fibre digestibility was observed in I-diet that had

the greatest soluble fibre/total fibre proportion (SF/TF) (Table 2). On the contrary, the C-diet

that had only insoluble fibre, showed the lowest fibre digestibility, while DN-diet and P-diet

had intermediate values (Table 4). As expected fibre digestibility was positively correlated to

the SF/TF in the diet (r= 0·91; P<0·05). We also found positive correlation between fibre

digestibility and feed efficiency ratio (FER) (r= 0·46; P<0·05), and positive correlation

between SF/TF and FER (r= 0·55; P<0·05).

Despite showing similar feed intake and similar values for digestibility of starch

(Table 4), animals fed I-diet and C-diet had different FER (I-diet higher than C-diet) (Table

3). However, I- and C-diet had different SF/TF ratio (Table 2) and fibre digestibility (Table

4). On the other hand, animals fed P-diet (lower SF/TF) showed higher FER than animals fed

DN-diet (P<0·05) and similar to I-diet group (higher SF/TF) (Table 3). We noted that both

feed intake and fibre digestibility in P-diet group were slightly higher than in DN-diet group

(P>0·05) (Table 3 and 4). As we found a positive correlation between SF/TF and FER (r=

0·55; P<0·05), we considered that these differences may have influenced FER in these

animals. Besides, we did not find any correlation between starch digestibility and FER.

Jamroz et al. (2002) studied the digestibility and energy value of non-starch polysaccharides

(NSP) in birds and showed that the degradation of NSP in the gut (39 to 42%) resulted in

short chain fatty acids and contributed with 3·5% of the metabolisable energy. Robertson et

al. (1987) studied the digestibility and rate of degradation of water-insoluble dietary fibre in

pigs and showed that cellulose did not appear to be degraded, while vegetable fibre can have

its fibre cell wall matrix completely destroyed by the microbial digestion during gut transit.

Kienzle et al. (2001) studied the effect of cellulose on the digestibility of fat, protein and

energy in dogs. They found that cellulose did not decrease the digestibility of fat, but

decreased the digestibility of protein and energy. Besides, starch also decreased protein

digestibility and the effects of cellulose and starch appeared to be additive. Thus, these papers

support our findings, where experimental animals in I-diet (highest digestibility) and P-diet

(intermediate digestibility but high feed intake) showed higher feed efficiency ratio.

Concerning starch digestibility, C-diet and I-diet groups showed the highest but

similar levels, while DN-diet and P-diet showed the lowest values. It does not seam to have

any relation to the type neither to the percentage of starch in the diet because C-diet had

50·1% of corn starch, while I-diet, DN-diet, and P-diet had 50·3%, 48·4%, and 51·2 %,

respectively, of bean starch on dry matter basis. In addition, both digestible starch and

resistant starch of these bean varieties were previously evaluated by the authors in raw grains

(unpublished data). The levels, on dry matter basis, ranged from 28·4 to 31·5% and from 3·0

to 4·4%, respectively, but were not statistically different among them. So, as both digestible

starch and resistant starch were similar among the bean varieties used in experimental diets,

we do not believe that they could have caused any effect on the differences of starch

digestibility in these groups.

Comparing experimental groups, there was positive correlation between faecal

moisture and faecal weight (r= 0·77; P<0·01), and they were higher in P-diet than in I-diet

groups (Table 5). We can observe that animals fed diets with low SF/TF (consequently higher

levels of insoluble fibre) produced faeces with higher levels of these two parameters.

Surprisingly, animals fed control diet (only insoluble fibre) showed the lowest levels for both

moisture and weight. Concerning faecal pH, experimental groups showed similar values,

despite the different SF/TF proportion in the diets. However, control animals showed higher

faecal pH, even when compared to P-diet with the lowest SF/TF proportion. Burrows et al.

(1982) showed that faecal weight and water content increased linearly, while digestibility of

dry matter decreased, when cellulose was added in dog´s diets. Unexpectedly, we did not find

any correlation between fibre digestibility and faecal moisture, faecal weight, or faecal pH.

On the other hand, we found a negative correlation between starch digestibility and faecal

moisture (r= -0·64, P<0·05), and between starch digestibility and faecal weight (r= -0·86,

P<0·05), but a positive correlation between starch digestibility and faecal pH (r= 0·51,

P<0·05). These data were important to explain why animals fed diets with high starch

digestibility (C-diet and I-diet) showed lower values for faecal moisture, and faecal weight,

but higher values for faecal pH. We assume that C-diet and I-diet groups, with a remarkable

difference in SF/TF proportion (0 and 0·25, respectively), and fibre digestibility (68 and 86%,

respectively), showed similar values for faecal weight because I-diet group produced faeces

with higher faecal moisture, compensating the weight of the insoluble fibre in faeces of C-diet

animals. Thus, we presume that in this study starch digestibility had more prominent influence

on faecal weight and moisture than even insoluble fibre fraction that has low digestibility.

We found a positive correlation between final animal body weight and liver weight of

animals (r= 0·76, P<0·05). So, liver/body weight ratio was used to compare the groups.

Groups fed experimental diets had liver/body weight ratio similar to control (Table 6).

Based on this data, we can say that all the animals showed a well distributed weight gain. To

evaluate fat retention, we measured epididymal fat weight. We also found a positive

correlation between final animal body weight and epididymal fat weight (r= 0·52, P<0·05). C-

diet animals showed the highest epididymal fat/body weight ratio (P<0·05; Table 6), and no

significant difference was observed in epididymal fat/body weight ratios among experimental

diets. However, we found a negative correlation between epididymal fat/body weight ratio

and fibre digestibility (r= -0·58; P<0·05). This indicates that the intake of bean-based diets

that had higher fibre digestibility was associated with a lower fat retention. As the weight gain

among all groups were similar, it is possible to presume that animals fed bean-based diets

increased their lean body mass instead of fat body mass. These data are supported by studies

that related type and fibre content to digestibility of nutrients. For example, Burrows et al.

(1982) showed that high cellulose level diets decrease digestibility of both dry matter (from

90 to 70%) and ash (from 43 to 32%). On the other hand, Larsen et al. (1994) showed that

high viscosity diets delayed passage rate and, consequently, increased the absorption of amino

acids in rats. Thus, as experimental diets had lower insoluble fibre level than control diet, it is

easy to understand that experimental animals would have greater digestibility of the nutrients,

mainly amino acids, showing a similar weight gain but lower fat retention with low

epididymal fat weight.

Experimental diets yielded lower total cholesterol levels compared to control (Table

6). Although no statistically significant difference was observed among experimental groups,

animals fed I-diet that had the highest SF/TF proportion, showed the lowest cholesterol levels

(P>0·05). In addition, I-diet and DN-diet yielded lower HDL cholesterol levels compared to

control, while P-diet showed intermediate values. Some authors have used the HDL/total

cholesterol ratio to express plasma lipid levels (Shutler et al., 1989). In our study this

parameter was slightly higher in experimental animals, but was not significantly different

among all groups.

Cholesterol and HDL levels were found to be positively correlated to epididymal

fat/body weight ratio (r=0·59 and 0·57; P<0·05). So, animals with higher fat retention had a

tendency to show upper blood lipid levels. In addition, total cholesterol level was negatively

correlated to fibre digestibility (r= -0·84; P<0·05) and positively correlated to faecal pH

(r=0·76; P<0·05). These data explain the findings that the animals fed I-diet, with high fibre

digestibility, showed lower cholesterol levels in comparison to C-diet (low fibre digestibility).

There was a reduction around 19·34 to 28·58% in serum cholesterol levels when we

compare any of experimental diets to C-diet. We can see that significant reduction in serum

cholesterol levels occurred when SF/TF proportion was equal to or higher than 0·11 (as in P-

diet). Although no statistically significant difference was observed among bean-diets, animals

fed I-diet (highest SF/TF proportion) had the lowest cholesterol level.

Although animals fed I-diet showed lower serum triglyceride values (around 10%)

than controls, this difference was not statistically significant (Table 6). So, animals fed bean-

based diets, even with high SF/TF proportion, did not show any important lowering effect on

serum triglycerides. Shutler et al. (1989) also found no changes in plasma triacylglycerol

levels of normocholesterolemic men after daily consumption of Phaseolus vulgaris, despite

significant reductions in total plasma cholesterol levels. There is evidence that, at least in

humans, the lipid-lowering effect of beans seems to be more remarkable on cholesterol

fraction. For example, Birketvedt et al. (2002) studied the effects of bean fibre on serum

lipids and fat excretion in faeces in overweight and obese volunteers. After a 3 months period,

the supplemented group, but not the placebo-group, showed reduction in serum cholesterol

and increased in fat excretion in faeces. However, triacylglycerol and HDL did not change

in either group. Hunninghake et al. (1994) showed that hypercholesterolemic subjects

receiving a dietary fibre supplementation of 10 g/d or 20 g/d showed significantly reduction in

total cholesterol and LDL/HDL ratio, but no reduction in serum HDL or triglycerides. In our

study, bean diet had lipid-lowering effect on both total cholesterol and HDL fraction. It is

known that around 50% of cholesterol in rats is transported as HDL (Olson & Schneeman,

1998; Simunek & Bartonova, 2005). In our animals, these levels ranged from 37·70 to

44·21%. Hence, it is understandable that a reduction in cholesterol levels would be

accompanied by a reduction in HDL values. This can be seen through HDL/total cholesterol

ratios which were not different among all groups. It shows that the percentage of total

cholesterol which was transported as HDL cholesterol did not change in any group. Thus,

both total cholesterol and HDL cholesterol levels were equally decreased by the diets.

Amígo et al. (1992) studied the effects of each constituent of beans on serum and

biliary lipids in rats. They found that both whole bean and bean starch-based diets had

lowering effects on serum cholesterol and triglyceride. Neither bean protein, bean lipid or

bean fibre alone had this effect. Thus, they presumed that the active component of beans was

linked to starch fraction and saponins. However, they could not discard a role of soluble

fibres, since this fraction was not evaluated. In our study all the experimental diets had the

same starch content. Moreover, the most significant changes in serum lipids have occurred

between Iraí and control group, which had no difference in their starch digestibility. In

addition, the percentage of bean starch in experimental diets ranged from 18 to 25·6%. P-diet

had 1·9% and 4·2% more bean starch than I-diet and DN-diet, respectively. However, P-diet

did not cause any lowering effect on cholesterol levels. Thus, in the present study bean starch

content seems not to be responsible for this lowering effect. Our results suggest that the lipid

lowering effect was linked to the soluble fraction of the bean fibre.

There was no difference in fasting levels of blood glucose among groups (Figure 1).

Compared to C-diet animals, blood glucose levels of DN-diet and P-diet were significantly

higher at 30 min, while glucose levels of I-diet and P-diet were significantly lower at 60 min.

The moment for the rise in blood glucose (glycaemia peak) occurred at 60 min for animals fed

C-diet, but at 30 min for those fed experimental bean diets.

Aller et al. (2004) compared the effect of a high soluble fibre content diet (82·2% of

total dietary fibre) against a control one (18·9% of total dietary fibre) in healthy humans. They

found 12·3% reduction on fasting glucose levels, but no significant changes on insulin levels.

In the present study, the experimental bean diets had no effect on fasting blood glucose,

despite the difference in SF/TF proportions. This could be related to the range of SF/TF ratio

evaluated that was much lower than that used by Aller et al. (2004).

Based only on blood glucose values, the SF effects on plasma glycaemia did not seem

to be of remarkable importance. However, an assessment of the areas under the glycaemic

curve provided noteworthy information. The total areas under the curve (AUC) for all

experimental bean diets were lower than for control group (P<0·05) (Table 7). When AUC

were calculated separately for each period of time, the I-diet showed more stable values

during the whole 90 minutes than the other two bean cultivars. Comparing P-diet (lowest

SF/TF) to I-diet (highest SF/TF), P-diet showed higher areas over the first 15 min and lower

areas during the 60-90 min interval. Based on this finding, animals fed I-diet kept

postprandial plasma glucose values more stable along the time. Dilawari et al. (1981)

compared the effects of different carbohydrate sources on plasma glucose. They found that

the postprandial rise in plasma glucose and AUC were lower when carbohydrates were taken

as beans (Phaseolus vulgaris) when compared to glucose. This can be explained because

pulses and legumes are rich sources of fibre in the form of galactomannans

(polysaccharides) which are not hydrolyzed by the digestive enzymes of man and are hence

called unabsorbable carbohydrate (Leeds et al. 1979). Moreover, galactomannans present in

pulses are more viscous than fibre present in others cereals and viscosity of the dietary fibre

has been shown to correlate positively with the reduction in postprandial plasma glucose

levels (Jenkins et al. 1978). Thus, besides the desirable effect of soluble fibre viscosity on

blood glucose, we observed that SF/TF ratio can also influence the variability in AUC values.

Animals from all groups had similar weight gain and final body weight. However,

control animals showed higher values for epididymal fat/body weight ratio than those fed

experimental bean diets. This may be related to the lower area under the curve (AUC) in

animals fed experimental bean diets when compared to controls. Pawlak et al. (2001)

observed that rats fed a high glycaemic index (GI) diet showed higher epididymal fat mass

than low GI group, despite comparable body weights. They also observed that high GI diet

resulted in higher insulin response, which may underlie the increased fat deposition. In

addition, we found a negative correlation between epididymal fat/body weight ratio and fibre

digestibility. Thus, diets with higher SF/TF reduced tendency to fat retention.

5. Conclusions

According to this study, even normolipidemic-normoglycaemic rats fed bean diets

with high soluble fibre to total fibre proportion (SF/TF: equal to or higher than 0·11) can have

lowering effects on serum cholesterol levels (22·3 to 33%), lower glycaemic responses

(glycaemix index), and lower fat retention. These results point out that consumption of bean

cultivars with high SF/TF would help people, not only during nutritional treatment, but as an

important tool against hypercholesterolemia, diabetes, and obesity. For this reason, food

composition tables should bring data concerning SF/TF proportion, because bean varieties

with higher soluble to insoluble fibre ratio could be preferred for nutritional and clinical

purposes.

Acknowledgements

Authors thank to Centro Nacional de Pesquisa de Arroz e Feijão – EMBRAPA (Santo

Antônio de Goiás, Goiás, Brazil) for donation of beans, to Doles Reagentes e Equipamentos

para Laboratórios Ltda (Goiânia, GO, Brazil) for donation of lipid assay kits and to

Novozymes Latin América Ltda. for donation of enzymes. T. Emanuelli is the recipient of a

CNPq research Fellowship (proc. 304257/2004-4). L.P. Silva is the recipient of

CAPES/PRODOC fellowship. R.G. Barbosa is the recipient of a PIBIC/CNPq-UFSM

Fellowship (2005-2006).

References

Aller R, de Luis DA, Izaola O, La Calle F, del Olmo L, Fernandez L, Arranz T & Hernandez

JM (2004) Effect of soluble fibre intake in lipid and glucose levels in healthy subjects: a

randomized clinical trial. Diabetes Res Clin Pract 65, 7-11.

Amígo L, Marzolo MP, Aguilera JM, Hohlberg A, Cortés M & Nervi F (1992) Influence of

different dietary constituents of beans (Phaseolus vulgaris) on serum and biliary lipids in

the rat. J Nutr Biochem 3, 486-490.

Anderson JW & Gustafson NJ (1988) Hypocholesterolemic effects of oat and bean products.

Am J Clin Nutr 48, 749-753.

AOAC (1995) Official methods of analysis of the association of the official analysis chemists

(16

ed.). Arlington, Virginia: Association of Official Analytical Chemists.

Birketvedt GS, Travis A, Langbakk B & Florholmen JR (2002) Dietary supplementation with

bean extract improves lipid profile in overweight and obese subjects. Nutrition 18, 729-733.

Bjorck I & Elmstahl HJ (2003) The glycaemic index: Importance of dietary fibre and other

food properties. Proc Nutr Soc 62, 201-206.

Burrows CF, Kronfeld DS, Banta Ca & Merritt AM (1982) Effects of fiber on digestibility

and transit time in dogs. J Nutr 112, 1726-1732.

Dabai FD, Walker AF, Sambrook IE, Welch VA, Owen RW & Abeyasekera S (1996) Effects

on blood lipids and faecal steroids of five legume species incorporated into a semi-purified,

hypercholesterolemic rat diet. Brit J Nutr 75, 557-571.

Dilawari JB, Kamath PS, Batta RP, Mukewar S & Raghavan S (1981) Reduction of

postprandial plasma glucose by Bengal gram dal (Cicer arietinum) and Rajmah (Phaseolus

vulgaris). Am J Clin Nutr 34, 2450-2453.

Fukushima M, Ohashi T, Kojima M, Ohba K, Shimizu H, Sonoyama K & Nakano M (2001)

Low density lipoprotein receptor mRNA in rat liver is affected by resistant starch of beans.

Lipids 36, 129-134.

Hunninghake DB, Miller VT, LaRosa JC, Kinosian B, Brown V, Howard WJ, DiSerio FJ &

O’Connor RR (1994) Hypocholesterolemic effects of a dietary fibre supplement. Am J Clin

Nutr 59, 1050-1054.

Jamroz D, Jakobsen K, Bach Knudsen KE, Wiliczkiewicz A & Orda J (2002) Digestibility

and energy value of non-starch polysaccharides in young chickens, ducks and geese, fed

diets containing high amount of barley. Comp Biochem Physiol A Mol Integr Physiol 131,

657-668.

Jenkins DJ, Wolever TM, Leeds AR et al. (1978) Dietary fibres, fibre analogues and glucose

tolerance: importance of viscosity. Br Med J 1, 1392-1394.

Kienzle E, Dobenecker B & Eber S (2001) Effect of cellulose on the digestibility of high

starch versus high fat diets in dogs. J Anim Physiol Anim Nutr 85, 174-185.

Larsen FM, Wilson MN & Moughan PJ (1994) Dietary fiber viscosity and amino acid

digestibility, proteolytic digestive enzyme activity and digestive organ weights in growing

rats. J Nutr 124, 833-841.

Leeds AR, Bolster NR & Truswell AS (1979) Meal viscosity, gastric emptying and glucose

absorption in the rat. Proc Nutr Soc 38,44A.

Messina MJ (1999) Legumes and soybeans: overview of their nutritional profiles and health

effects. Am J Clin Nutr 70, 439-450.

Olson B & Schneeman BO (1998) Alimentary lipemia is enhanced in fibre-fed rats. J Nutr

128, 1031-1036.

Panlasigui LN, Panlilio LM & Madrid JC (1995) Glycaemic response in normal subjects to

five different legumes commonly used in the Philippines. Int J Food Sci Nutr 46, 155-160.

Pari L & Venkateswaran S (2003) Effect of an aqueous extract of Phaseolus vulgaris on

plasma insulin and hepatic key enzymes of glucose metabolism in experimental diabetes.

Pharmazie 58, 916-919.

Pawlak DB, Bryson MJ, Denyer GS & Brand-Miller JC (2001) High glycemic index starch

promotes hypersecretion of insulin and higher body fat in rats without affecting insulin

sensitivity. J Nutr 131, 99-104.

Reeves PG, Nielsen HF & Fahey GC (1993) AIN-93 Purified diets for laboratory rodents:

final report of the American Institute of Nutrition ad hoc writing Committee on the

reformulation of the AIN-76 rodent diet. J Nutr 123, 1939-1951.

Robertson JA, Murison SD & Chesson A (1987) Estimation of the potential digestibility and

rate of degradation of water-insoluble dietary fiber in the pig cecum with a modified

nylon bag technique. J Nutr 117, 1402-1409.

Rosa COB, Costa NMB, Leal PFG & Oliveira TT (1998 a) The cholesterol-lowering effect of

black beans (Phaseolus vulgaris, L.) without hulls in hypercholesterolemic rats. Arch

Latinoam Nutr 48, 299-305.

Rosa COB, Costa NMB, Nunes RM & Leal PFG (1998 b) The cholesterol-lowering effect of

black , carioquinha and red beans (Phaseolus vulgaris, L.) in hypercholesterolemic rats.

Arch Latinoam Nutri 48, 306-310.

Shutler SM, Bircher GM, Tredger JA, Morgan LM, Walker AF & Low AG (1989) The effect

of daily baked bean (Phaseolus vulgaris) consumption on the plasma lipid levels of young,

normo-cholesterolemic men. Br J Nutr 61, 257-265.

Simunek J & Bartonova H (2005) Effect of dietary chitin and chitosan on cholesterolemia of

rats. Acta Vet Brno 74, 491-499.

Thorne MJ, Thompson LU & Jenkins DJA (1983) Factors affecting starch digestibility and

the glycaemic response with special reference to legumes. Am J Clin Nutr 38, 481-488.

Walter M (2005) Amido resistente: metodologias de quantificação e resposta biológica em

ratos. Dissertação (Mestrado em Ciência e Tecnologia de Alimentos), Universidade

Federal de Santa Maria, Santa Maria, Brasil

Figure caption

Figure 1. Glycaemic curves according to diet type. C-diet: control diet; I-diet: Iraí diet; P-diet:

Pérola diet; DN-diet: Diamante Negro diet. * Significantly different from control at the same

time (P<0

05).

Fig. 1

0 153045607590

Time (minutes)

C-diet I-diet P-diet DN-diet

100

110

120

130

140

150

160

170

Blood glucose (mg/dl)

Table 1. Content of diets (g/100 g diet)

Diets

Nutrients

Control Pérola Diamante Negro Iraí

Bean flour 0 19·30 22·83 20·62

Fibre (cellulose) 5 0 0 0

Caseine 20 15·33 13·63 14·84

Corn starch 52·90 43·31 41·49 42·49

Table 2. Fibre content of diets (g/100 g diet)

Diets

Nutrients

Control Pérola Diamante Negro Iraí

Total fibre (TF) 5 5 5 5

Soluble fibre (SF) 0 0·55 0·97 1·28

Insoluble fibre 5 4·45 4·03 3·72

SF/TF proportion 0 0·11 0·19 0·25

Table 3. Effect of bean-containing diet on biological parameters of rats

Diets

Control Pérola Diamante Negro Iraí

Final body weight (g) 188·51±5·28 192·68±4·25 194·23±4·19 197·41±5·85

Feed intake (g/day) 16·72±0·17 17·34±0·27 16·21±0·35 16·48±0·31

Body weight gain (g) 117·02±3·24 121·90±3·92 115·03±3·58 127·78±3·33

Feed efficiency ratio (g/g) 0·310±0·002

0·320±0·003

0·300±0·003

0·330±0·005

Results are expressed as mean value±standard error of the mean (n=8).

Parameters were measured during growth period (26–44 days of age).

Values within the same horizontal row with no common superscript differ significantly (P < 0·05, Duncan’s test).

Table 4. Digestibility (g/100 g of dry weight) of dry matter, starch, and fibre of the diets

Diets

Digestibility (%)

Control Pérola Diamante Negro Iraí

Dry matter 92·84±0·08

90·47±0·35

90·29±0·17

92·58±0·16

Starch 94·24±0·14ª 92·30±0·44

91·93±0·48

94·61±0·32ª

Fibre 68·22±1·31

79·47±1·03

77·13±1·66

86·82±0·41

Results are expressed as mean value±standard error of the mean (n=8).

Values within the same horizontal row with no common superscript differ significantly (P < 0·05, Duncan’s test).

Table 5. Effect of diets on faecal parameters

Diets

Control Pérola Diamante Negro Iraí

Faecal weight (g/day) 1·11±0·04

1·69±0·08

1·62±0·03

1·22±0·05

Faecal pH 6·19±0·07ª 5·68±0·05

5·86±0·04

5·93±0·06

Faecal moisture (g/100 g of fresh weight) 27·34±0·68

37·47±1·12ª 32·22±0·72

30·63±1·19

Results are expressed as mean value±standard error of the mean (n=8).

Values within the same horizontal row with no common superscript differ significantly (P < 0·05, Duncan’s test).

Table 6. Effect of diets on liver and epididymal fat weight and on serum lipids concentration

Diets

Control Pérola Diamante Negro Irai

Liver/body weight ratio (mg/g) 37·53±0·48

37·03±0·42

37·11±0·31

38·95±0·70

Epididymal fat/body weight ratio (mg/g) 16·86±0·62

13·51±0·65

12·85±0·36

12·61±0·92

Total cholesterol (mg/dL)

115·43±4·18

92·82±3·11

93·11±3·45

82·44±3·98

HDL cholesterol (mg/dL)

50·93±2·96

43·99±2·59

36·.61±2·52

33·.67±2·33

HDL/total cholesterol ratio

37·70±0·67 42·95±1·11 44·21±2·03 39·35±3·64

Triglyceride (mg/dL)

87·72±1·95 97·18±6·06 82·46±3·20 78·21±6·76

Results are expressed as mean value±standard error of the mean (n=8).

Values within the same horizontal row with no common superscript differ significantly (P < 0·05, Duncan’s test).

Table 7. Area under the glycaemic curve (% of control value)

Interval of time (min)

Diet

0 – 15 15 - 30 30 - 45 45 - 60 60 - 90 0 - 90

Control 100

100 100 100

100

Pérola 104·75±1·61

104·79±2·43 102·74±1·76 90·16±2·11

87·26±1·86

95·75±0·44

Diamante Negro 100·45±0·83

103·65±0·80 99·56±2·08 94·29±1·86

89·40±1·44

95·93±1·20

Iraí 98·66±1·55

98·51±1·70 100·99±1·98 95·24±1·20

92·11±1·49

96·18±0·71

Results are expressed as mean value±standard error of the mean (n=8).

Values within the same column with no common superscript differ significantly (P < 0·05, Duncan’s test).

4 DISCUSSÃO

O feijão comum é um alimento amplamente consumido pelos povos ao redor do

mundo, principalmente por aqueles economicamente menos favorecidos. Apresenta

propriedades nutritivas e funcionais inquestionáveis, principalmente em função de seu perfil

bioquímico peculiar. No entanto, as cultivares plantadas nas mais variadas regiões do globo

apresentam diferenças significativas na sua composição, tanto de macro quanto de

micronutrientes e podem, com o passar dos anos, alterar seu perfil bioquímico e perder suas

características genéticas originais.

Em nosso estudo comparamos o perfil bioquímico de 16 diferentes cultivares de feijão

recomendadas para plantio no RS, e que foram colhidas em 2 anos consecutivos. Observamos

que as cultivares não mudaram significativamente suas composições químicas entre as safras,

exceto pela pequena variação nos teores de umidade, matéria seca e fibra total. A despeito do

aumento nos teores de fibra alimentar total (FT) na safra 2002/2003 ter sido significativo, os

teores de fibra alimentar insolúvel (FI) e de fibra alimentar solúvel (FS) não aumentaram

significativamente, demonstrando que este incremento foi realmente discreto e se diluiu

quando as frações foram analisadas separadamente. É sabido que os feijões podem variar a

sua composição química conforme o local de plantio (SAMMAN et al., 1999). No entanto,

não encontramos estudos que avaliassem as possíveis alterações no perfil de macro e

micronutrientes entre cultivares de feijão de uma mesma variedade genética, mas oriundos de

safras distintas. Nosso estudo demonstrou que feijões plantados em um mesmo local, sob as

mesmas condições de cultivo tendem a manter suas características ao longo de pelo menos 2

safras. Resultados semelhantes já haviam sido observados em cultivares de aveia, trigo e arroz

(SILVA, 2002; STORCK, SILVA, & FAGUNDES, 2005).

Entre as cultivares estudadas observamos uma grande variação nos teores de

macronutrientes, principalmente de fibra alimentar solúvel (106%) e amido resistente (100%),

seguidos por amido digestível (77%) e fibra alimentar insolúvel (70%). Já o teor de proteína

foi o parâmetro de menor variação (36%) entre as sementes. Baseado nisto podemos concluir

que as diferentes variedades genéticas de feijão estudadas mantiveram esta característica

peculiar do alto conteúdo protéico (21,24-29,06 g/100 g MS) e sem diferenças importantes

entre elas.

Utilizando análise de agrupamento para categorizar as cultivares com

características químicas semelhantes obtivemos 4 grupos distintos quanto ao perfil de

macronutrientes. As cultivares Guateian 6662 e Rio Tibagi compuseram o grupo com os

maiores teores de proteínas, de fibra solúvel e de amido disponível. Este perfil peculiar torna

estas cultivares mais adequadas às recomendações para prevenção e tratamento de doenças

como diabete, deslipidemias, obesidade e doenças cardiovasculares. Além disto, são úteis

como fonte alimentar para populações de risco nutricional. As cultivares Iraí, Minuano e TPS

Bonito compuseram o grupo que apresentou os maiores teores de fibra insolúvel e de amido

resistente. Porém, foram as com menor teor de proteínas. Assim, poderiam ser indicadas em

situações onde uma oferta maior de fibras insolúveis fosse necessária (ex.: constipação) ou

onde uma restrição protéica fosse indicada (ex.: insuficiência renal crônica).

Da mesma forma que para os macronutrientes, os minerais também foram agrupados

pela semelhança em seus teores. Obtivemos 4 grupos distintos. O grupo formado pelas

cultivares FTS Magnífico, FTS Soberano, Guateian 6662, Pérola, Rio Tibagi, TPS Bionobre e

TPS Nobre foi o que apresentou os maiores teores de todos os minerais avaliados. Novamente

as cultivares Guateian 6662 e Rio Tibagi estão presentes, reforçando o valor nutricional destas

variedades no contexto deste estudo.

Por outro lado, as cultivares Diamante Negro, Macanudo e Valente compuseram o

grupo com os menores valores para os macronutrientes, exceto pelo valor intermediário de

proteína; as cultivares Iapar 31, Iraí e Macanudo compuseram o grupo com os menores

valores para os micronutrientes. Assim, estas cultivares foram as de mais baixo valor

nutricional quanto aos macro e micronutrientes, respectivamente.

Este estudo demonstrou, ainda, uma correlação negativa entre o tamanho da semente e

o teor de proteína bruta (PB). Desta forma, sementes grandes, muitas vezes preferidas para o

consumo, são as de menor valor nutricional para este nutriente. LEMOS et al. (2004)

avaliaram as características agronômicas (produtividade de grãos, número de vagens/planta,

número de grãos/vagem e massa de 100 grãos) e tecnológicas (teor de proteína bruta, tempo

de cozimento, capacidade de hidratação e presença de grãos de casca dura que não hidratam)

de 29 genótipos de feijão. Observaram que genótipos com os maiores teores protéicos nem

sempre se sobressaíram nas outras características avaliadas, especialmente em relação à

produtividade. Já genótipos com as maiores produtividades apresentaram teores de PB abaixo

da média. Assim, concluíram que o teor de PB é inversamente proporcional à produtividade

de grãos. Desta forma, se o objetivo do melhoramento genético for apenas gerar cultivares

altamente produtivas ou cultivares mais atraentes ao consumidor (grãos grandes), o teor

protéico certamente declinará com o passar do tempo, com surgimento de cultivares de menor

valor nutricional.

Outra observação feita foi a não existência de correlação entre os teores de fibra bruta

(FB) e fibra alimentar (total, solúvel ou insolúvel). Assim, médicos e nutricionistas que

utilizam as informações contidas em rótulos de produtos ou em tabelas de composição

alimentar devem ficar atentos pois, algumas vezes, apenas os valores referentes à FB estão

explicitados. Como visto, estes valores não traduzem as reais quantidades de fibra dietética,

que detém importância funcional.

A literatura relata de forma contraditória algumas modificações na composição

química dos grãos de feijão cozidos após o armazenamento, tanto em relação aos teores de

amido disponível quanto de amido resistente (OSORIO-DIAZ et al., 2003; VARGAS-

TORRES et al., 2004; LANDA-HABANA et al., 2004). Decidimos, então, estudar os efeitos

do armazenamento (refrigeração a 4

C por 4 dias ou congelamento a -20

C por 28 dias) sobre

os teores de amido disponível (AD), amido resistente (AR), fibra total (FT), fibra insolúvel

(FI) e fibra solúvel (FS) nestas sementes. O tipo de armazenamento escolhido baseou-se nas

formas domésticas habitualmente utilizadas para conservar feijões após seu cozimento.

Nossos resultados demonstraram que os grãos cozidos e armazenados apresentaram redução

dos níveis do AD e elevação dos níveis de AR, tanto após refrigeração a 4

C por 4 dias

quanto após congelamento a -20

C por 28 dias. Estas alterações nos teores de AD e de AR

foram menos intensas após congelamento e foram influenciadas pelos teores de AR

encontrados nas sementes cruas, pois o congelamento só alterou o AD e o AR em feijões

cujos níveis de AR eram baixos antes do cozimento. Assim, em situações onde uma dieta com

baixo teor de AD e alto teor de AR estiver indicada, como no tratamento e controle do diabete

e da obesidade, feijões cozidos e refrigerados por apenas 4 dias podem ter um efeito

metabólico desejável.

Quanto às fibras, tanto a refrigeração quanto o congelamento pelos períodos estudados

não determinaram mudanças em relação aos níveis encontrados logo após o cozimento. Desta

forma grãos de feijão ao serem cozidos e refrigerados passam a apresentar uma redução nos

teores de AD e aumento nos teores de AR, sem alterar os teores de fibra. Assim, o perfil

nutricional destes grãos seria modificado, tornando-os mais adequados ao controle e

prevenção de doenças que cursam com alterações no metabolismo dos lipídeos e/ou da

glicose, bem como da obesidade.

A literatura pertinente enfoca, cada vez mais, as recomendações sobre o perfil da dieta

que a população humana deveria ingerir para recuperar ou manter sua saúde. O feijão, pela

sua composição química peculiar, enquadra-se nestas recomendações dietéticas. Além disto,

sua fração fibra solúvel possui propriedades redutoras dos lipídeos séricos (ANDERSON &

GUSTAFSON, 1988) e dos níveis glicêmicos (THORNE et al., 1983; BJORCK &

ELMSTAHL, 2003).

Desta forma, o consumo de feijões por pessoas com distúrbios do controle das

gorduras e/ou da glicose sanguíneas poderia auxiliá-las a manter seus níveis de lipídeos e

glicemia mais estáveis e próximos da normalidade. Assim, complicações inerentes às

deslipidemias e à hiperglicemia, bem como a evolução para situações mais críticas, poderiam

ser amenizadas. Mas será que este tipo de alimento também poderia influenciar de forma

benéfica os níveis de lipídeos e de glicose em pessoas saudáveis ou em risco de desenvolver

estes distúrbios metabólicos? Nosso estudo demonstrou que mesmo animais

normolipidêmicos, uma vez submetidos a dietas em que a fibra alimentar foi substituída por

feijões apresentaram valores mais baixos de colesterol total (19,3 a 28,6% menores) que

animais alimentados com a dieta padrão, sendo esta redução relacionada à porcentagem de

fibra solúvel do feijão. No entanto, para os triglicerídeos séricos, apesar de os valores

encontrados nos animais alimentados com as dietas Iraí e Diamante Negro serem 10,8 e 6%

menores que nos controles, respectivamente, esta redução não alcançou significância

estatística. A literatura relata que uma redução de 1% nos níveis de colesterol total reduzem

em 2% o risco de uma pessoa desenvolver doenças do coração (RIFKIND, 1984). Assim, por

dedução, os animais teriam de 38,6 a 57,2% menos risco de desenvolverem doença arterial

coronariana. No entanto, não há relatos da percentagem de redução necessária nos níveis de

triglicerídeos para que sejam observados efeitos benéficos sobre a saúde. Se as percentagens

forem semelhantes, estas taxas de redução detectadas pelo nosso estudo, apesar de modestas,

poderão ser de relevância clínica e nutricional.

ANDERSON & GUSTAFSON (1988) estudaram os efeitos de dietas contendo aveia

ou feijões, os quais são ricos em fibra solúvel, sobre os níveis de lipídeos em homens

hipercolesterolêmicos. Observaram redução nos níveis de colesterol total, LDL, triglicerídeos

e glicemia de jejum. Juntamente com outros dados de literatura concluíram que uma

ingestão diária de 100-200 g de feijões cozidos reduziria os níveis de colesterol séricos em

12% a curto prazo, mas de 20-25% a longo prazo. Isto levaria a uma redução estimada de 40-

50% nos riscos para doença arterial coronariana. No entanto, CHEN et al. (2006) avaliaram os

efeitos da fibra solúvel de aveia (8 g/dia) dada por um período de 3 meses a um grupo de

voluntários sadios e normocolesterolêmicos. Ao final do estudo não observaram redução

significativa nos níveis de colesterol total ou LDL no grupo estudado. HEIJNEN et al. (1996)

estudaram os efeitos do amido resistente (AR) sobre os níveis séricos de colesterol total,

colesterol HDL e LDL, e triglicerídeos em homens e mulheres sadios e normolipidêmicos.

Para isto utilizaram AR tipo 2 (amido de milho cru) e AR tipo 3 (amido de milho

retrogradado) sob a forma de suplementos diários de 30 g por 3 semanas. Concluíram que

nenhuma das formas de AR foi capaz de reduzir os lipídeos séricos em relação ao grupo

controle. Assim, pode-se sugerir que o teor de AR das dietas experimentais parece não ter

influenciado os nossos resultados. Além disso, observou-se uma correlação negativa entre a

digestibilidade da fibra e o teor de colesterol. Podemos concluir que feijões apresentam um

efeito redutor nos níveis de lipídeos séricos, principalmente do colesterol, mesmo em

situações de normolipidemia, e que este efeito está ligado a fração digerível da fibra.

A avaliação das respostas glicêmicas após a ingestão das dietas experimentais

demonstrou valores inferiores que os determinados pela dieta controle. DILAWARI et al.

(1981) avaliaram os efeitos de dietas contendo 50 g de carboidratos de diferentes fontes

(incluindo feijão) sobre os níveis de glicose sanguínea pós-prandiais. Compararam estes

valores com os de uma curva glicêmica após ingestão de dextrose. Para isto, 6 voluntários

sadios ingeriram as dietas experimentais em dias sucessivos e de forma randomizada. Em

relação à curva controle observaram que a dieta contendo feijão determinou pico glicêmico

mais tardio e de menor valor, e menor área sob a curva nos primeiros 60 minutos pós-

prandiais. Em nosso estudo, os valores de glicose sanguínea dos animais no período pós-

prandial apresentaram-se mais estáveis e com menores valores para as áreas sob a curva

(índice glicêmico-IG). Isto demonstra que mesmo ratos normoglicêmicos alimentados com

dietas contendo feijões com elevados teores de fibra solúvel podem apresentar uma melhor

regulação do metabolismo da glicose sanguínea, pois, devido ao baixo IG, estas dietas

possivelmente produzem menores picos de insulina.

OU et al.(2001) estudaram in vitro os mecanismos pelos quais a fibra dietética

reduz a glicemia pós-prandial. Concluíram que 3 são os mecanismos possíveis: as fibras

dietéticas aumentam a viscosidade do suco intestinal, reduzindo a difusão da glicose; ligam-se

à glicose reduzindo sua concentração e sua disponibilidade na luz do intestino; retardam a

ação da alfa-amilase devido ao encapsulamento do amido e da enzima, além de atuarem de

forma inibitória diretamente sobre a enzima. JENKINS et al. (1978) estudaram os efeitos de

diferentes tipos de fibra durante um teste de tolerância à glicose em 6 voluntários sadios.

Observaram que fibras dietéticas com viscosidade elevada são mais adequadas para uso

terapêutico em pacientes diabéticos por reduzirem os níveis glicêmicos pós-prandiais, sendo

esta redução diretamente proporcional à viscosidade da fibra. Assim, a ingestão de feijões

com altos teores de fibra solúvel teria um efeito regulador da glicemia pós-prandial nestas

situações clínicas.

PAWLAK, KUSHNER, & LUDWIG (2004) estudaram os efeitos em ratos de dietas

com diferentes índices glicêmicos (IG) devido ao tipo de carboidrato (HC) utilizado (HC de

alto IG; HC de baixo IG). Observaram que a dieta com alto IG causou maior acúmulo de

gordura, menor massa magra, maiores áreas sob a curva da glicemia e da insulina, e maiores

níveis de triglicerídeos plasmáticos. Concluíram que, como fator independente, o IG pode

causar obesidade e aumentar os riscos de diabete e doenças do coração em ratos. BRENNAN

(2005) também relatou conclusões semelhantes em seu estudo de revisão: dietas contendo

alimentos de elevado IG estão relacionadas com aumento de peso, obesidade e diabete,

provavelmente devido à alteração na expressão da enzima ligada à síntese de lipídeos,

modificação da resposta hormonal e estimulação da gliconeogênese. Em nosso estudo, através

da análise do ganho de peso dos animais e do peso do tecido adiposo epididimal, observamos

uma menor retenção de gordura corporal nos animais alimentados com dietas contendo feijão

em relação aos controles. Este dado nos leva a crer que, a despeito da não medição dos

valores de insulina pós-prandial, possivelmente estes eram inferiores nos ratos alimentados

com dietas contendo feijão que nos controles. Assim, devido à estreita relação entre IG, pico

de insulina e deposição de gordura, pacientes com obesidade ou em controle de peso

poderiam ser beneficiados da ingestão regular de feijões em sua dieta. Isto porque feijões,

além de possuírem teores elevados de fibra solúvel, também apresentam amido digestível

considerado de baixo IG que, segundo BRENNAN (2005), seria o fator primordial no impacto

glicêmico determinado por um alimento.

Sendo assim, o consumo de feijões com teores elevados de fibra solúvel dentro de

um plano alimentar poderia auxiliar no controle e prevenção de doenças metabólicas como o

diabete melito, as deslipidemias, a obesidade e as doenças cardiovasculares. Para isto, a busca

por cultivares que apresentem este perfil e que mantenham estes teores ao longo do tempo

deveria ser estimulada.

5 CONCLUSÕES

Quanto às características físico-químicas das sementes de feijão concluímos que:

1. A composição química das sementes variou significativamente de uma cultivar

para outra sendo possível categorizá-las em quatro diferentes grupos de acordo

com os macronutrientes (PB, FT, FI, FS, AD e AR) bem como pelos

micronutrientes (Fe, Zn, Mn, Cu, Ca, Mg e P); as cultivares Guateian 6662 e

Rio Tibagi apresentaram os melhores perfis de nutrientes, com altos teores de

PB, FS, AD, Fe e Zn.;

2. Exceto pelos níveis de massa seca, umidade e fibra dietética total, as

características físico-químicas das cultivares estudadas mantiveram-se estáveis

ao longo das duas safras;

3. A estocagem de feijões cozidos e armazenados sob refrigeração ou sob

congelamento não alterou os níveis de FT, FI ou FS, mas reduziu os teores de

AD e aumentou os teores de AR, principalmente em sementes cujos teores de

AR eram menores antes do cozimento.

Quanto aos efeitos das dietas experimentais em ratos normolipidêmicos e

normoglicêmicos concluímos que os animais alimentados com dietas contendo cultivares de

feijão apresentaram redução dos níveis séricos de colesterol total, menor índice glicêmico,

valores mais estáveis de glicemia pós-prandial e menor retenção de gordura corporal, sendo

que estes efeitos foram mais marcantes no grupo alimentado com a dieta Iraí (FS/FT: 0,26).

6 BIBLIOGRAFIA

ABD-EL-SAMEI, M. H.; LASZTITY, R. Comparative study on the aminoacids composition

in three local Phaseolus vulgaris seeds varieties. Z Lebensm Unters Forsch, v. 178, n. 1, p.

24-26, 1984.

ACEVEDO, E.; VELAZQUEZ-CORONADO, L.; BRESSANI, R. Changes in dietary fiber

content and its composition as affected by processing of black beans (Phaseolus vulgaris,

Tamazulapa variety). Plant Foods Hum Nutr, v. 46, n. 2, p. 139-145, 1994.

ALLER, R. et al. Effect of soluble fibre intake in lipid and glucose levels in healthy subjects:

a randomized clinical trial. Diabetes Res Clin Pract, v. 65, p. 7-11, 2004.

ALMEIDA, T. C; CANÉCHIO FILHO, V. Principais Culturas vol. II. 2

ed. Instituto

Campineiro de Ensino Agrícola, Campinas, 1987.

AMÍGO, L. et al. Influence of different dietary constituents of beans (Phaseolus vulgaris) on

serum and biliary lipids in the rat. J Nutr Biochem, v. 3, p. 486-490, 1992.

ANDERSON, J. W. et al. Hypocholesterolemic effects of oat-bran or bean intake for

hypercholesterolemic men. Am J Clin Nutr, v. 40, p. 1146-1155, 1984.

ANDERSON, J. W.; GUSTAFSON, N. J. Hypocholesterolemic effects of oat and bean

products. Am J Clin Nutr, v. 48, p. 749-753, 1988.

ANTUNES, P. L. et al. Valor nutricional de feijão (Phaseolus vulgaris L.), cultivares Rico 23,

Carioca, Piratã-1 e Rosinha-G2. Rev Bras de Agrociência, v. 1, p. 12-18, 1995.

BAZZANO, L. A. et al. Legume consumption and risk of coronary heart disease in US men

and women. Arch Intern Med, v. 161, p. 2573-2578, 2001.

BJORCK, I.; ELMSTAHL, H. J. The glycaemic index: Importance of dietary fibre and other

food properties. Proc Nutr Soc, v. 62, p. 201-206, 2003.

BRASIL. Portaria n. 36 de 15 de julho de 2002. MAPA. Diário Oficial da República

Federativa do Brasil, Brasília, 16 de julho de 2002 a.

BRASIL. Portaria n. 124 de 11 de novembro de 2002. MAPA. Diário Oficial da República

Federativa do Brasil, Brasília, 18 de novembro de 2002 b.

BRENNAN, C. S. Dietary fibre, glycaemic response, and diabetes. Mol Nutr Food Res, v.

49, p. 560-570, 2005.

CASTELLÓN, R. E. R. et al. Composição elementar e caracterização da fração lipídica de

seis cultivares de caupi. R Bras Eng Agric Ambiental, v. 7, n. 1, p.149-153, 2003.

CHEN, J. et al. A randomized controlled trial of dietary fiber intake on serum lipids. Eur J

Clin Nutr, v. 60, n. 1, p. 62-68, 2006.

CORREA, P. Epidemiological correlations between diet and cancer frequency. Cancer Res,

v. 41, p. 3685-3689, 1981.

DABAI, F. D. et al. Effects on blood lipids and faecal steroids of five legume species

incorporated into a semi-purified, hypercholesterolemic rat diet. Brit J Nutr, v. 75, p. 557-

571, 1996.

DILAWARI, J. B. et al. Reduction of postprandial plasma glucose by Bengal gram dal (Cicer

arietinum) and Rajmah (Phaseolus vulgaris). Am J Clin Nutr, v. 34, p. 2450-2453, 1981.

EMBRAPAARROZ e FEIJÃO. Acesso em 20 ago. 2004. Disponível em:

<http://www.cnpaf.embrapa.br/feijao/historia.htm/>.

ESTEVEZ, A. M. et al. Effect of processing on some chemical and nutritional characteristics

of pre-cooked and dehydrated legumes. Plant Foods Hum Nutr, v. 41, n. 3, p. 193-201,

1991.

FOSTER-POWELL, K.; MILLER, J. B. International tables of glycemic index. Am J Clin

Nutr, v. 62, p. 871-890, 1995.

FUKUSHIMA, M. et al. Low density lipoprotein receptor mRNA in rat liver is affected by

resistant starch of beans. Lipids, v. 36, p. 129-134, 2001.

GIOVANNUCCI, E. L. et al. Insulin and colon-cancer. Canc Causes Contr, v. 6, p. 164-179,

1995.

HAN, K. H. et al. Resitant starches of beans reduce the serum cholesterol concentrations in

rats. J Nutr Sci Vitaminol, v. 49, n. 4, p. 281-286, 2003.

HANGEN, L. A.; ENNINK, M. R. Consumption of black beans and navy beans (Phaseolus

vulgaris) reduced azoxymethane-induced colon cancer in rats. Nutr Cancer, v. 44, p. 60-65,

2003.

HARO, M. I. et al. Chemical composition, dietary fiber and mineral content of frequently

consumed foods in northwest Mexico. Arch Latinoam Nutr, v. 45, n. 2, p. 145-150, 1995.

HEIJNEN, M. L. et al. Neither raw nor retrograded resistant starch lowers fasting serum

cholesterol concentrations in healthy normolipidemic subjects. Am J Clin Nutr, v. 64, n. 3, p.

312-318, 1996.

HERNANDEZ-UNZON, H. Y.; ORTEGA-DELGADO, M. L. Phytic acid in stored

common bean seeds (Phaseolus vulgaris). Plant Foods Hum Nutr, v. 39, n. 3, p. 209-221,

1989.

HUGHES, J. S.; GANTHAVORN, C.; WILSON-SANDERS, S. Dry beans inhibit

azoxymethane-induced colon carcinogenesis in F344 rats. J Nutr, v. 127, p. 2328-2333, 1997.

HUGHES, J. S.; SWANSON, B. G. Soluble and insoluble dietary fiber in cooked common

bean (Phaseolus vulgaris L.) seeds. Food Microstruct, v. 8, p. 15-21, 1989.

JENKINS, D. J. et al. Dietary fibres, fibre analogues and glucose tolerance: importance of

viscosity. Br Med J, v. 1, p. 1392-1394, 1978.

KUTOS, T. et al. Dietary fiber content of dry and processed beans. Food Chem, v. 80, p.

231-235, 2003.

LANDA-HABANA, L. et al. Effect of cooking procedures and storage on starch

bioavailability in common beans (Phaseolus vulgaris L.). Plant Foods Hum Nutr, v. 59, p.

133-136, 2004.

LEMOS, L. B. et al. Características agronômicas e tecnológicas de genótipos de feijão do

grupo comercial Carioca. Pesq Agropec Bras, v. 39, p. 319-326, 2004.

LUDWIG, D. D. S. The glycemic index – Physiological mechanisms relating to obesity,

diadetes, and cardiovascular diease. J Am Med Assoc, v. 287, p. 2414-2423, 2002.

MARCONI, E. et al. Physicochemical, nutritional and microstructural characteristics of

chickpeas (Cicer arietinum L.) and common beans (Phaseolus vulgaris L.) following

microwave cooking. J Agric Food Chem, v. 48, n. 12, p. 5986-5994, 2000.

MARTIN-CABREJAS, M. A. et al. Modifications to physicochemical and nutritional

properties of hard-to-cook beans (Phaseolus vulgaris L.) by extrusion cooking. J Agric Food

Chem, v. 47, n. 3, p. 1174-1182, 1999.

MCKEOWN-EYSSEN, G. Epidemiology of colorectal-cancer revisited are serum

triglycerides and/or plasma-glucose associated with risk. Cancer Epidemiol Biomarkers

Prev, v. 3, p. 687-695, 1994.

MESSINA, M. J. Legumes and soybeans: overview of their nutritional profiles and health

effects. Am J Clin Nutr, v. 70, n. 3, p. 439-450, 1999.

OSORIO-DIAZ, P. et al. Effect of processing and storage time on in vitro digestibility and

resistant starch content of two bean (Phaseolus vulgaris L.) varieties. J Sci Food Agric, v. 83,

p. 1283-1288, 2003.

OU, S. et al. In vitro study of possible role of dietary fiber in lowering postprandial serum

glucose. J Agric Food Chem, v. 49, n. 2, p. 1026-1029, 2001.

PARI, L.; VENKATESWARAN, S. Effect of an aqueous extract of Phaseolus vulgaris on

plasma insulin and hepatic key enzymes of glucose metabolism in experimental diabetes.

Pharmazie, v. 58, p. 916-919, 2003.

PAWLAK, D. B.; KUSHNER, J. A.; LUDWIG, D. S. Effects of dietary glycaemic index on

adiposity, glucose homeostaseis, and plasma lipids in animals. Lancet, v. 3, p. 778-785, 2004.

RIFKIND, B. M. The Lipid Research Clinics coronary primary prevention trial results.2. The

relationship of reduction in incidence of coronary heart-disease to cholesterol lowering. J Am

Med Assoc, v. 251, p. 365-374, 1984.

ROSA, C. O. B. et al. The cholesterol-lowering effect of black beans (Phaseolus vulgaris, L.)

without hulls in hypercholesterolemic rats. Arch Latinoam Nutr, v. 48, p. 299-305, 1998 a.

ROSA, C. O. B. et al. The cholesterol-lowering effect of black , carioquinha and red beans

(Phaseolus vulgaris, L.) in hypercholesterolemic rats. Arch Latinoam Nutr, v. 48, p. 306-

310, 1998 b.

SAMMAN, N. et al. Composition of different bean varieties (Phaseolus vulgaris) of

northwestern Argentina (region NOA): cultivation zone influence. J Agric Food Chem, v.

47, n. 7, p. 2685-2689, 1999.

SANDHU, M. S.; DUNGER, D. B.; GIOVANNUCCI, E. L. Insulin, insulin-like growth

factor-I (IGF-I), IGF-I binding proteins, their biologic interactions, and colorectal cancer. J

Nat Cancer Inst, v. 94, p. 972-980, 2002.

SAURA-CALIXTO, F. et al. Formation of resistant starch in deproteinized and non-

deproteinized beans. Eur J Clin Nutr, v. 46, p. 109-111, 1992.

SHIMELIS, E. A.; RAKSHIT, S. K. Proximate composition and physico-chemical properties

of improved dry bean (Phaseolus vulgaris L.) varieties grown in Ethiopia. Lebensm Wiss

Technol, v. 38, p. 331-338, 2005.

SILVA, L. P. da. Composição Química de Trigo e de Aveia e Efeito dos Teores e

Proporções de Fibra Alimentar sobre a Resposta Biológica de Frangos de Corte e Ratos.

2002. Tese (Doutorado em Zootecnia) - Faculdade de Agronomia, Universidade Federal do

Rio Grande do Sul, Porto Alegre, 2002.

SING, P. N.; FRASER, G. B. Dietary risk factors for colon cancer in low-risk population.

Am J Epidemiol, v. 148, p. 761-774, 1998.

SOTELO, A.; SOUZA, H.; SANCHEZ, M. Comparative study of the chemical composition

of wild and cultivated beans (Phaseolus vulgaris). Plant Foods Hum Nutr, v. 47, n. 2, p. 93-

100, 1995.

STORCK, C. R.; SILVA, L. P. da; FAGUNDES, C. A. A. Categorizing rice cultivars based

on differences in chemical composition. J Food Compos Anal, v. 18, p. 333-341, 2005.

THORNE, M. J.; THOMPSON, L. U.; JENKINS, D. J. A. Factors affecting starch

digestibility and the glycaemic response with special reference to legumes. Am J Clin Nutr,

v. 38, p. 481-488, 1983.

VARGAS-TORRES, A. et al. Starch digestibility of five cooked black bean (Phaseolus

vulgaris L.) varieties. J Food Compos Anal, v. 17, p. 605-612, 2004.

VASQUEZ-CARRILLO, G.; CARDENAS-RAMOS, F. Physical, technological and protein

characteristics of wild and cultivated beans (Phaseolus vulgaris L). Arch Latinoam Nutr, v.

42, n. 2, p. 201-209, 1992.

VIEIRA, C. O Feijoeiro-Comum: Cultura, Doenças e Melhoramento. Editora UFV-

Universidade Federal de Viçosa, Viçosa, MG, 1967.

VIEIRA, R. F.; VIEIRA, C.; VIEIRA, R. F. Leguminosas graníferas. Editora UFV-

Universidade Federal de Viçosa, Viçosa, MG, 2001.

YANEZ, E. et al. Nutritive value evaluated on rats of new cultivars of common beans

(Phaseolus vulgaris) released in Chile. Plant Foods Hum Nutr, v. 47, n. 4, p. 301-307, 1995.

YOKOYAMA, L. P. Tendências de mercado e alternativas de comercialização de feijão.

Embrapa arroz e feijão - comunicado técnico no. 43, 2002.

7 ANEXOS

ANEXO 1 - Roteiro para autores

Guia para redação e edição de manuscrito científico a ser submetido à revista

LWT- FOOD SCIENCE AND TECHNOLOGY

Guide for Authors

LWT - Food Science and Technology is an international journal that publishes innovative

papers in the fields of food chemistry, biochemistry, microbiology, technology and nutrition.

The work described should be innovative either in the approach or in the methods used. The

significance of the results either for the science community or for the food industry must also

be specified. Contributions that do not fulfil these requirements will not be considered for

review and publication. Submission of a paper will be held to imply that it presents original

research, that it has not been published previously, and that it is not under consideration for

publication elsewhere.

SUBMISSION OF MANUSCRIPTS

As of 1 June 2006, submission for all types of manuscripts to LWT - Food Science and

Technology will proceed totally online. Via the Elsevier Editorial System (EES) website for

this journal, http://ees.elsevier.com/lwt, you will be guided step-by-step through the

creation and uploading of the various files. The system automatically converts source files to

a single Adobe Acrobat PDF version of the article, which is used in the peer-review process.

Please note that even though manuscript source files are converted to PDF at submission for

the review process, these source files are needed for further processing after acceptance. All

correspondence, including notification of the Editor's decision and requests for revision, takes

place by e-mail generated by EES and via the Author's homepage, removing the need for a

hard-copy paper trail. Authors must submit revisions via EES. Authors may send queries

concerning the submission process, manuscript status, or journal procedures to

[email protected].

Books for review should be sent to the Editors; all other correspondence should be sent

directly to the publishers.

Four types of peer-reviewed papers will be published:

Short Reviews. These should present a focused aspect on a topic of current interest or an

emerging field. They are not intended as comprehensive literature surveys covering all aspects

of the topic. They should aim to give balanced, objective assessments by giving due reference

to relevant published work, and not merely present the prejudices of individual authors or

summarise only work carried out by the authors or by those with whom the authors agree.

Undue speculation should also be avoided. These short reviews will receive priority in

publication.

Reviews. Concise reviews of a scientific or applied field should include all major findings

and bring together reports from a number of sources.

Research Papers. Reports of complete, scientifically sound, original research which

contributes new knowledge to its field. The paper must be organised as described below.

Research Notes. Brief reports of scientifically sound, original research of limited scope of

new findings. Research Notes have the formal organisation of a full paper. Such notes will

receive priority of publication.

LWT - Food Science and Technology is an international journal that publishes innovative

papers in the fields of food chemistry, biochemistry, microbiology, technology and nutrition.

The work described should be innovative either in the approach or in the methods used. The

significance of the results either for the science community or for the food industry must also

be specified. Contributions that do not fulfil these requirements will not be considered for

review and publication. Submission of a paper will be held to imply that it presents original

research, that it has not been published previously, and that it is not under consideration for

publication elsewhere.

Peer Reviews It is the journal policy to keep the peer reviewing anonymous. Names of

reviewers are only revealed if they are in agreement with the request of the author. When

submitting a manuscript, authors may indicate names of experts who are not

suitable/appropriate for reviewing the paper.

Language Manuscripts should be written in English. Authors whose mother tongue is not

English are strongly advised to have their manuscripts checked by someone familiar with

English scientific writing. The Editors reserve the right to make any necessary linguistic

alterations without consulting the authors.

Preparation of Manuscripts Authors should aim at producing 6 printed A4 pages (research

papers) or 3 printed pages (research notes), which corresponds to approximately 18 and 9

pages of double-spaced type, respectively. All papers should follow the new style for LWT.

Please see Volume 36 issue 1 onward. Manuscripts should be double-spaced throughout, with

a left-hand margin of not less than 4 cm. On the first page, immediately below the title, give

authors' names, affiliations and business addresses. Number the lines of each page. If your

manuscript cites submitted but unpublished papers, send one copy of each of these papers

with your manuscript.

The SI system (Systeme International d'Unites, often referred to as 'International Units') must

be used for reporting units of measurement. Do not use %, ppm, M, N, etc. as units for

concentrations. If analytical data are reported, replicate analyses must have been carried out

and the number of replications must be stated.

Standard error or other evidence of reliability of data must be given.

Editorial Style Title. The title of the papers should be short but informative.

Abstract. Each article should include an abstract, not exceeding 200 words.

Introduction. In the Introduction, briefly review important prior publications and state the

reasons for the investigation being reported.

Methods. Results. Discussion. Following the Introduction, authors are free to structure papers

as appropriate. However, for the sake of clarity and uniformity, the above or similar section

headings are recommended. If necessary, each section may be divided into further

subsections, but do not use more than two levels for subtitles.

The Materials and Methods section must provide enough detail that a competent worker can

repeat the experiments. However, detailed descriptions of well-known methods should be

avoided in the experimental section. References to the relevant literature are sufficient. The

Discussion should not be a compilation of current literature, but a consideration of the

significance and consequences of the authors' present findings.

References: All publications cited in the text should be presented in a list of references

following the text of the manuscript. In the text refer to the author's name (without initials)

and year of publication (e.g. "Steventon, Donald and Gladden (1994) studied the effects..." or

"...similar to values reported by others (Anderson, Douglas, Morrison & Weiping, 1990)...").

For 2-6 authors all authors are to be listed at first citation. At subsequent citations use first

author et al.. When there are more than 6 authors, first author et al. should be used throughout

the text. The list of references should be arranged alphabetically by authors' names and should

be as full as possible, listing all authors, the full title of articles and journals, publisher and

year. The manuscript should be carefully checked to ensure that the spelling of authors' names

and dates are exactly the same in the text as in the reference list. References should be given

in the following form:

Watt, D. K., Brasch, D. J., Larsen, D. S., & Melton, L. D. (1999). Isolation, characterisation,

and NMR study of xyloglucan from enzymatically depectinised and non-depectinised apple

pomace. Carbohydrate Polymers, 39(2), 165-180.

Closs, C. B., Roberts, I. D., Conde-Petit, B., & Eschler, F. (1997). Phase separation and

rheology of aqueous amylopectin/ galactomannan systems. In E. J. Windhab, & B. Wolf.

Proceedings of the 1st international symposium on food rheology and structure (pp. 233-237).

Hannover: Vincentz Verlag.

Stephen, A. M. (1995). Food polysaccharides and their applications. New York: Marcel

Dekker. Wurzburg, O. B. (1986). Cross-linked starches. In O. B. Wurzburg, Modified

starches: properties and uses (pp. 41). Boca Raton, FL: CRC Press.

Tables

Tables should be numbered and headed by a short but informative title. The experimental

conditions, as far as they are necessary for understanding, should be given. Use no vertical

and few horizontal lines. Probabilities may be indicated by *P < 0.05, **P <0.01 and ***P

<0.001. Tables should be submitted on separate sheets.

Figures and Illustrations

Figures must be provided on separate sheets. Do not repeat material already included in

tables. Figures should be comprehensible without reference to the text. All drawings and

graphs should not exceed 20 x 20.5 cm in size. All illustrations should be consecutively

numbered. Keys to graphs etc., should not appear on the figure, but only in the figure legend.

Legends should consist of a short title followed by a brief description of experimental

100

conditions and, where necessary, a key. Where it is necessary to use photographs, these

should again be clearly labelled and numbered. Authors are strongly advised to consult

Elsevier's artwork instructions before uploading any graphics files for electronic submission.

These are available at http://authors.elsevier.com/artwork.

Colour Illustrations

If, together with your accepted article, you submit usable colour figures then Elsevier will

ensure, at no additional charge, that these figures will appear in colour on the web (e.g.,

ScienceDirect and other sites) regardless of whether or not these illustrations are reproduced

in colour in the printed version. For colour reproduction in print, you will receive information

regarding the costs from Elsevier after receipt of your accepted article. For further

information on the preparation of electronic artwork, please see

http://authors.elsevier.com/artwork. Please note: Because of technical complications which

can arise by converting colour figures to ?grey scale? (for the printed version should you not

opt for colour in print) please submit in addition usable black and white prints corresponding

to all the colour illustrations.

Key Words

Four to five pertinent key words should be provided. If possible the Food Science and

Technology Abstracts (FSTA) Thesaurus should be used (IFIS Publ., Shinfield, Reading RG2

9BB, UK http://www.foodScienceCentral.com).

Proofs

When your manuscript is received at the Publisher it is considered to be in its final form.

Proofs are not to be regarded as 'drafts'. One set of page proofs in PDF format will be sent by

e-mail to the corresponding author, to be checked for typesetting/editing. No changes in, or

additions to, the accepted (and subsequently edited) manuscript will be allowed at this stage.

Proofreading is solely your responsibility. A form with queries from the copy editor may

accompany your proofs. Please answer all queries and make any corrections or additions

required. The Publisher reserves the right to proceed with publication if corrections are not

communicated. Return corrections within two working days of receipt of the proofs. Should

there be no corrections, please confirm this. Elsevier will do everything possible to get your

article corrected and published as quickly and accurately as possible. In order to do this we

need your help. When you receive the (PDF) proof of your article for correction, it is

important to ensure that all of your corrections are sent back to us in one communication.

Subsequent corrections will not be possible, so please ensure your first sending is complete.

Note that this does not mean you have any less time to make your corrections, just that only

one set of corrections will be accepted.

Offprints

Twenty-five offprints will be supplied free of charge. If colour has been paid for within the

article, 100 extra offprints will be supplied free of charge. Additional offprints and copies of

the issue can be ordered at a specially reduced rate using the order form sent to the

corresponding author after the manuscript has been accepted. Orders for reprints (produced

after publication of an article) will incur a 50% surcharge.

Upon acceptance of an article, authors will be asked to transfer copyright (for more

information on copyright see

http://authors.elsevier.com). This transfer will ensure the

widest possible dissemination of information. A letter will be sent to the corresponding author

101

confirming receipt of the manuscript. A form facilitating transfer of copyright will be

provided. If excerpts from other copyrighted works are included, the author(s) must obtain

written permission from the copyright owners and credit the source(s) in the article. Elsevier

has preprinted forms for use by authors in these cases: contact Elsevier Ltd., Global Rights

Department, The Boulevard, Langford Lane, Oxford, OX5 1GB, UK; phone: (+44) 1865

843830, fax: (+44) 1865 853333, e-mail: [email protected]

Author Enquiries

Authors can keep a track on the progress of their accepted article, and set up e-mail alerts

informing them of changes to their manuscript's status, by using the "Track a Paper" feature

of Elsevier's Author Gateway. Other questions or queries will also be dealt with via the

website http://authors.elsevier.com. Contact details for questions arising after acceptance of

an article, especially those related to proofs, are provided when an article is accepted for

publication.

102

ANEXO 2 - Roteiro para autores

Guia para redação e edição de manuscrito científico a ser submetido à revista

British Journal of Nutrition

The British Journal of Nutrition is an international peer-reviewed journal which publishes

original papers, review articles (including those critically re-examining published information

and the conclusions drawn from it), technical notes and short communications in all branches

of nutritional science. Short communications will be expedited through the review process.

The underlying aim of all work should be, as far as possible, to develop nutritional concepts.

Prospective authors should note that they (or their institutions) now retain the copyright

of their material published in the British Journal of Nutrition. As a contributor you are

asked to follow the guidelines set out below. Prospective authors may also contact the

Editorial Office directly on + 44 (0)207 371 6225 (telephone), +44 (0)207 602 1756 (fax), or

[email protected] (email).

Papers submitted for publication should be written in English and be as concise as possible.

The BJN now operates an on-line submission and reviewing system (eJournalPress).

Authors should submit to the following address: http://bjn.msubmit.net/. Receipt of

papers will be acknowledged immediately.

Papers should be accompanied by a statement signed by each author (or by the submitting

author on behalf of the others) to the effect that the conditions laid down in the Directions to

Contributors are accepted. The statement should affirm that the submission represents original

work that has not been published previously and which is not currently being considered by

another journal, and that if accepted for the British Journal of Nutrition it will not be

published elsewhere in the same form, in English or in any other language, without the written

consent of the Editor-in-Chief. It should also confirm that each author has seen and approved

the contents of the submitted manuscript. The submission letter should be accompanied by

a completed copy of the ‘Licence to Publish’ (in lieu of copyright transfer) as

reproduced in the January 2004 issue (vol. 91, no 1) of the British Journal of Nutrition or

on the Nutrition Society’s web pages (http://www.nutritionsociety.org); the Society no

longer requires copyright of the material published in the journal, only a ‘Licence to Publish’,

the authors or their institution retaining the copyright.

When substantial revisions are required to manuscripts, authors are given the opportunity

to do this once only, the need for any further changes should at most reflect only minor issues.

Should there be a change in the authorship then a new Licence to Publish should be submitted

to reflect that change.

Authors' names should be given without titles or degrees and one forename may be given

in full. The name and address of the institution where the work was performed should be

given. Any necessary descriptive material about the author, e.g. Beit Memorial Fellow, should

appear at the end of the paper in the acknowledgments section.

Manuscripts should bear the name and address, together with telephone and fax numbers

and email address, of the person to whom correspondence is to be sent and should also give a

shortened version of the paper's title, not exceeding forty-five letters and spaces in length,

suitable for a running title in the published pages of the work.

If a paper requiring revision is not resubmitted within 3 months, it may, on resubmission,

be deemed a new paper and the date of receipt altered accordingly.

Short Communications. Papers submitted as Short Communications should consist of an

Abstract (250 words maximum), and no more than 3000 words of text (including references).

103

Each Short Communication can include up to two Tables or one Table and one Figure, but

these will be at the expense of text (one half-page Table or Figure is equivalent to about 500

words in two columns or 250 words in one column).

Nutrition Discussion Forum. Letters are invited which discuss, criticize or develop themes

put forward in papers published in the Journal, or which deal with matters relevant to it. They

should not, however, be used as a means of publishing new work.

Acceptance will be at the discretion of the Editorial Board, and editorial changes may be

required. Wherever possible, letters from responding authors will be included in the same

issue.

Form of Papers Submitted for Publication. The onus of preparing a paper in a form

suitable for sending to press lies with the author. Authors are advised to consult a current

issue in order to make themselves familiar with the practice of the British Journal of Nutrition

as to typographical and other conventions, layout of tables and so on. Papers will not be

accepted as part of a numbered series; instead there should be a short common title separated

by a colon from a subtitle more specific to the paper. Sufficient information should be given

to permit repetition of the published work by any competent reader of the Journal. Authors

are invited to nominate up to four potential referees who may then be asked by the Editorial

Board to help review the work.

Papers should be in double-spaced typescript on paper with wide margins (2 cm or more).

At the ends of lines, words should not be hyphenated unless hyphens are to be printed. A

space of 50mm should be left at the top of the first sheet. Line-numbered paper is encouraged.

Spelling should generally be that of the Concise Oxford Dictionary (1995), 9th ed. Oxford:

Clarendon Press. Paper should normally be divided into the following parts:

(a) Abstract: each paper must open with an abstract of not more than 250 words. The

abstract should be a single paragraph of continuous text outlining the aims of the work, the

experimental approach taken, the principal results, and the conclusions and their relevance to

nutritional science.

(b) Introduction: it is not necessary to introduce a paper with a full account of the

relevant literature, but the introduction paragraph should indicate briefly the nature of the

question asked and the reasons for asking it.

(d) Results: these should be given as concisely as possible, using figures or tables as

appropriate.

(e) Discussion: while it is generally desirable that the presentation of the results and

the discussion of their significance should be presented separately, there may be occasions

when combining these sections may be beneficial. Authors may also find that additional or

alternative sections such as 'conclusions' may be useful.

(f) Acknowledgments: these should be given in a single paragraph after the discussion

and be as brief as possible.

(g) References: these should be given in the text thus: Sebrell & Harris (1967) showed

that ..., or ... has been shown (Wallace & West, 1982); where a paper to be cited has more

than two authors, citations should appear thus: (Peto et al. 1981). Where more than one paper

has appeared in one year for which the first name in a group of three or more authors is the

same, the reference should be given as follows: Adams et al. (1962a,b,c) ..., or ... (Adams et

al. 1962a,b,c). In the text, references grouped together should be given in chronological order

thus: ... (Wallace & West, 1982; Lau, 1988). At the end of the paper, on a page(s) separate

from the text, references should be listed in alphabetical order according to the name of the

first author of the publication quoted and should include the author's initials and the title of

104

the paper. When an article has more than ten authors only the names of the first three

authors should be given followed by et al. Names and initials of authors of unpublished work

should be given in the text and not included in the References. Titles of journals should

appear in their abbreviated form using the NICB LinkOut page

http://www.ncbi.nlm.nih.gov/entrez/journals/loftext_noprov.html). References to books

and monographs should include the Publisher's name, the town of publication and the number

of the edition to which reference is made. Thus:

Ablett JG & McCance RA (1971) Energy expenditure of children with kwashiorkor. Lancet ii,

517–519.

Adams RL, Andrews FN, Gardiner EE, Fontaine WE & Carrick CW (1962a) The effects of

environmental temperature on the growth and nutritional requirements of the chick.

Poultry Sci 41, 588–594.

Adams RL, Andrews FN, Rogler JC & Carrick CW (1962b) The protein requirement of 4-

week-old chicks as affected by temperature. J Nutr 77, 121–126.

Adams RL, Andrews FN, Rogler JC & Carrick CW (1962c) The sulfur amino acid

requirement of the chick from 4 to 8 weeks as affected by temperature. Poultry Sci 41,

1801–1806.

Agricultural Research Council (1981) The Nutrient Requirements of Pigs. Slough:

Commonwealth Agricultural Bureaux.

Clément K, Vaisse C, Lahlou N, et al. (1998) A mutation in the human leptin receptor gene

causes obesity and pituitary dysfunction. Nature 392, 398–401.

Edmundson W (1980) Adaptation to undernutrition: how much food does man need? Soc Sci

Med 14 D, 19–126.

European Communities (1971) Determination of Crude Oils and Fats, Process A. Part 18,

Animal Feeding-stuffs, pp. 15–19. London: H. M. Stationery Office.

Hegsted DM (1963) Variation in requirements of nutrients – amino acids. Fed Proc 22, 1424–

1430.

Heneghan JB (1979) Enterocyte kinetics, mucosal surface area and mucus in gnotobiotes. In

Clinical and Experimental Gnotobiotics. Proceedings of the VIth International Symposium

on Gnotobiology, pp. 19–27 [TM Fliedner, H Heit, D Niethammer and H Pflieger, editors].

Stuttgart: Gustav Fischer Verlag.

Hill DC (1977) Physiological and biochemical responses of rats given potassium cyanide or

linamarin. In Cassava as an Animal Feed. Proceedings of a Workshop held at University of

Guelph, 1977. International Development Research Centre Monograph 095e, pp. 33–42 [B

Nestel and M Graham, editors]. Ottawa, Ont., Canada: International Development

Research Centre.

Lau EMC (1988) Osteoporosis in elderly Chinese (letter). Br Med J 296, 1263.

Louis-Sylvestre J (1987) Adaptation de l'ingestion alimentaire aux dépenses energétiques

(Adaptation of food intake to energy expenditure). Reprod Nutr Dév 27, 171–188.

Martens H & Rayssiguier Y (1980) Magnesium metabolism and hypomagnesaemia. In

Digestive Physiology and Metabolism in Ruminants, pp. 447–466 [Y Ruckebusch and P

Thivend, editors]. Lancaster: MTP Press Ltd.

Ministry of Agriculture, Fisheries and Food (1977) Energy Allowances and Feeding Systems

for Ruminants. Technical Bulletin no. 33. London: H.M. Stationery Office.

Peto R, Doll R, Buckly JD & Sporn MB (1981) Can dietary beta-carotene materially reduce

human cancer rates? Nature 290, 201–208.

Sebrell WH Jr & Harris RS (1967) The Vitamins, 2nd ed., vol. 1. London: Academic Press.

105

Technicon Instruments Co. Ltd (1967) Technicon Methodology Sheet N-36. Basingstoke:

Technicon Instrument Co. Ltd.

Van Dokkum W, Wesstra A & Schippers F (1982) Physiological effects of fibre-rich types of

bread. 1. The effect of dietary fibre from bread on the mineral balance of young men. Br J

Nutr 47, 451–460.

Wallace RJ & West AA (1982) Adenosine 5' triphosphate and adenylate energy charge in

sheep digesta. J Agric Sci (Cambridge) 98, 523–528.

Wilson J (1965) Leber's disease. PhD Thesis, University of London.

World Health Organization (1965) Physiology of Lactation. Technical Report Series no. 305.

Geneva: WHO.

References to material available on websites should include the full Internet address, and the

date of the version cited. Thus:

Department of Health (1997) Committee on Toxicity of Chemicals in Food Consumer

Products and the Environment. Statement on vitamin B

(pyridoxine) toxicity.

http://www.open.gov.uk/doh/hef/B

.htm

Mathematical Modelling of Nutritional Processes. Papers in which mathematical modelling

of nutritional processes forms the principal element will be considered for publication

provided: (i) they are based on sound biological and mathematical principles, (ii) they

advances nutritional concepts or identifies new avenues likely to lead to such advances, (iii)

assumptions used in their construction are fully described and supported by appropriate

argument, (iv) they are described in such a way that the nutritional purpose is clearly

apparent, (v) the contribution of the model to the design of future experimentation is clearly

defined.

Units. Results should be presented in metric units according to the International System of

Units (see Quantities, Units, and Symbols (1971) London: The Royal Society, and Metric

Units, Conversion Factors and Nomenclature in Nutritional and Food Sciences (1972)

London: The Royal Society – as reproduced in Proceedings of the Nutrition Society (1972)

31, 239–247).

Energy measurements should be expressed in joules.

For substances of known molecular weight, e.g. glucose, urea, Ca, Na, Fe, K, P, values

should be expressed as mol/l: for substances of indeterminate molecular weights, e.g.

phospholipids, proteins, and for trace elements, e.g. Cu, Zn, then g/l should be used.

Time. The 24 h clock should be used, e.g. 15.00 hours.

Statistical Treatment of Results.

Data from individual replicates should not be given for large experiments, but may be

given for small studies. The methods of statistical analysis used should be described, and

references to statistical analysis packages included in the text, thus: Statistical Analysis

Systems statistical software package version 6.11 (SAS Institute, Cary, NC, USA).

Information such as analysis of variance tables should be given in the paper only if they are

relevant to the discussion. A statement of the number of replicates, their average value and

some appropriate measure of variability is usually sufficient.

Comparisons between means can be made by using either confidence intervals or

significance tests. The most appropriate of such measures is usually the standard error of a

difference between means (SED), or the standard errors of the means (SE or SEM) when

these vary between means. The standard deviation (SD) is more useful only when there is

specific interest in the variability of individual values. The degrees of freedom associated with

SED, SEM or SD should also be stated. The number of decimal places quoted should be

106

sufficient but not excessive. Note that pH is an exponential number, as are the log(10)

values often quoted for microbial numbers. Statistics should be carried out on the scalar rather

than the expontential values.

If comparisons between means are made using confidence intervals (CI), these may be

presented as, e.g. ‘difference between means 0·73 g (95 % CI 0·314, 1·36)’. If significance

tests are used, a statement that the difference between the means for two groups of values is

(or is not) statistically significant should include the level of significance attained, preferably

as an explicit P value (e.g. P =0·016 or P =0·32) rather than as a range (e.g. P<0·05 or

P>0·05}. It should be stated whether the significance levels quoted are one-sided or two-

sided. Where a multiple comparison procedure is used, a description or explicit reference

should be given. Where appropriate, a superscript notation may be used in tables to denote

levels of significance; similar superscripts should denote lack of a significant difference.

Where the method of analysis is unusual, or if the experimental design is at all complex,

further details (e.g. experimental plan, raw data, confirmation of assumptions, analysis of

variance tables, etc.) should be included.

Figures. In curves presenting experimental results the determined points should be clearly

shown, the symbols used being, in order of preference, ¦, ¦, _, σ, ¦, ν, ×, . Curves and

symbols should not extend beyond the experimental points. Scale-marks on the axes should

be on the inner side of each axis and should extend beyond the last experimental point. Ensure

that lines and symbols used in graphs and shading used in histograms are large enough to be

easily identified when the figure is reduced to fit the printed page.

Figures and diagrams should be provided with numbers and lettering, preferably using

computer-based graphical programmes. The names of the authors, title of the paper and the

figure number should be given in pencil on the back of each figure. Legends for all figures

should be typed on a separate sheet and numbered. Each figure, with its legend, should be

comprehensible without reference to the text. The approximate position of each should be

indicated in the margin of the text.

Plates. The Journal will now also consider the inclusion of colour plates. The size of

photomicrographs may have to be altered in printing; in order to avoid mistakes, the

magnification should be shown by scale on the photograph itself. The scale with the

appropriate unit together with any lettering should be drawn by the author, preferably using

appropriate software.

Tables. Tables should carry headings describing their content and should be comprehensible

without reference to the text. The dimensions of the values, e.g. mg/kg, should be given at the

top of each column. Tables should be typed on separate sheets at the end of the text. Tables

should not be subdivided by ruled lines. Abbreviations in tables must be defined in footnotes.

Signs for footnotes should be used in the sequence: *†‡§|¶, then ** etc. (omit * or †, or both,

from the sequence if they are used to indicate levels of significance). The approximate

position should be indicated in the margin of the text.

Key Words. Authors are asked to supply three or four key words or phrases (each containing

up to three words) on the title page of the typescript. Please see a recent issue of the British

Journal of Nutrition Cumulative Index for examples of approved key words.

Chemical Formulas. These should be written as far as possible on a single horizontal line.

With inorganic substances, formulas may be used from first mention. With salts, it must be

stated whether or not the anhydrous material is used, e.g. anhydrous CuSO

, or which of the

different crystalline forms is meant, e.g. CuSO

.5H

O, CuSO

Descriptions of Solutions, Compositions and Concentrations. Solutions of common acids,

bases and salts should be defined in terms of molarity (M), e.g. 0·1 M-NaH

107

Compositions expressed as mass per unit mass (w/w) should have values expressed as ng,

μg, mg or g per kg; similarly for concentrations expressed as mass per unit volume (w/v), the

denominator being the litre. Concentrations or compositions should not be expressed on a

percentage basis. The common measurements used in nutritional studies, e.g. digestibility,

biological value and net protein utilization, should be expressed as decimals rather than as

percentages, so that amounts of available nutrients can be obtained from analytical results by

direct multiplication. See Metric Units, Conversion Factors and Nomenclature in Nutritional

and Food Sciences. London: The Royal Society, 1972 (para. 8).

Nomenclature of Vitamins. Most of the names for vitamins and related compounds that are

accepted by the Editors are those recommended by the IUNS Committee on Nomenclature.

See Nutrition Abstracts and Reviews A (1978) 48, 831–835.

Acceptable name Other names*

Vitamin A

Retinol Vitamin A

Retinaldehyde, retinal Retinene

Retinoic acid (all-trans or 13-cis) Vitamin A

acid

3-Dehydroretinol Vitamin A

Vitamin D

Ergocalciferol, ercalciol Vitamin D

calciferol

Cholecalciferol, calciol Vitamin D

Vitamin E

α-, β- and γ-tocopherols plus

tocotrienols

Vitamin K

Phylloquinone Vitamin K

Menaquinone-n (MK-n) † Vitamin K

Menadione Vitamin K

menaquinone,

menaphthone

Vitamin B

Thiamin Aneurin(e), thiamine

Vitamin B

Riboflavin Vitamin G, riboflavine,

Lactoflavin

Niacin

Nicotinamide Vitamin PP

Nicotinic acid

Folic Acid

Pteroyl(mono)glutamic acid Folacin, vitamin B

or M

Vitamin B

Pyridoxine Pyridoxol

Pyridoxal

Pyridoxamine

Vitamin B

Cyanocobalamin

108

Hydroxocobalamin Vitamin B12a or Vitamin B12b

Aquocobalamin

Methylcobalamin

Adenosylcobalamin

Inositol

Myoinositol Meso-inositol

Choline

Pantothenic acid

Biotin Vitamin H

Vitamin C

Ascorbic acid

Dehydroascorbic acid

*Including some names which are still in use elsewhere, but are not used by the British

Journal of Nutrition.

†Details of the nomenclature for these and other naturally occurring quinones should

follow the Tentative Rules of the IUPAC-IUB Commission on Biochemical Nomenclature

(see European Journal of Biochemistry (1975) 53, 15–18).

Generic descriptors. The terms vitamin A, vitamin C and vitamin D may still be used

where appropriate, for example in phrases such as ‘vitamin A deficiency’, ‘vitamin D

activity’.

Vitamin E. The term vitamin E should be used as the descriptor for all tocol and

tocotrienol derivatives exhibiting qualitatively the biological activity of α-tocopherol. The

term tocopherols should be used as the generic descriptor for all methyl tocols. Thus, the

term tocopherol is not synonymous with the term vitamin E.

Vitamin K. The term vitamin K should be used as the generic descriptor for 2-methyl-1,4-

naphthoquinone (menaphthone) and all derivatives exhibiting qualitatively the biological

activity of phylloquinone (phytylmenaquinone).

Niacin. The term niacin should be used as the generic descriptor for pyridine 3-carboxylic

acid and derivatives exhibiting qualitatively the biological activity of nicotinamide.

Vitamin B

. The term vitamin B

should be used as the generic descriptor for all 2-

methylpyridine derivatives exhibiting qualitatively the biological activity of pyridoxine.

Folate. Due to the wide range of carbon-substituted, unsubstituted, oxidized, reduced and

mono- or polyglutamyl side-chain derivatives of pteroylmonoglutamic acid which exist in

nature, it is not possible to provide a complete list. Authors are encouraged to use either the

generic name or the correct scientific name(s) of the derivative(s), as appropriate for each

circumstance.

Vitamin B

. The term vitamin B

should be used as the generic descriptor for all

corrinoids exhibiting qualitatively the biological activity of cyanocobalamin. The term

corrinoids should be used as the generic descriptor for all compounds containing the corrin

nucleus and thus chemically related to cyanocobalamin. The term corrinoid is not

synonymous with the term vitamin B

Vitamin C. The terms ascorbic acid and dehydroascorbic acid will normally be taken as

referring to the naturally occurring L-forms. If the subject matter includes other optical

isomers, authors are encouraged to include the L- or D-prefixes, as appropriate. The same is

true for all those vitamins which can exist in both natural and alternative isomeric forms.

Amounts of vitamins and summation. Weight units are acceptable for the amounts of

vitamins in foods and diets. For concentrations in biological tissues, SI units should be used;

109

however, the authors may, if they wish, also include other units, such as weights or

international units, in parentheses.

See Metric Units, Conversion Factors and Nomenclature in Nutritional and Food Sciences

(1972) paras. 8 and 14–20. London: The Royal Society.

Nomenclature of Fatty Acids and Lipids. In the description of results obtained for the

analysis of fatty acids by conventional gas–liquid chromatography, the shorthand designation

proposed by Farquhar JW, Insull W, Rosen P, Stoffel W & Ahrens EH (Nutrition Reviews

(1959), 17, Suppl.) for individual fatty acids should be used in the text, tables and figures.

Thus 18 : 1 should be used to represent a fatty acid with eighteen carbon atoms and one

double bond; if the position and configuration of the double bond is unknown. The shorthand

designation should also be used in the abstract. If the positions and configurations of the

double bonds are known, and these are important to the discussion, then a fatty acid such as

linoleic acid may be referred to as cis-9,cis-12-18 : 2 (positions of double bonds related to the

carboxyl carbon atom 1). However, to illustrate metabolic relationship between different

unsaturated fatty acid families, it is sometimes more helpful to number the double bonds in

relation to the terminal methyl carbon atom, n. The preferred nomenclature is then: 18 : 3n-3

and 18 : 3n-6 for α-linolenic and γ-linolenic acids respectively; 18 : 2n-6 and 20 : 4n-6 for

linoleic and arachidonic acids respectively and 18 : 1n-9 for oleic acid. Positional isomers

such as α- and γ-linolenic acid should always be clearly distinguished. It is assumed that the

double bonds are methylene-interrupted and are of the cis-configuration (see Holman RT in

Progress in the Chemistry of Fats and Other Lipids (1966) vol. 9, part 1, p. 3. Oxford:

Pergamon Press. Groups of fatty acids that have a common chain length but vary in their

double bond content or double bond position should be referred to, for example, as C

fatty

acids or C

polyunsaturated fatty acids. The modern nomenclature for glycerol esters should

be used, i.e. triacylglycerol, diacylglycerol, monoacylglycerol not triglyceride, diglyceride,

monoglyceride. The form of fatty acids used in diets should be clearly stated, i.e. whether

ethyl esters, natural or refined fats or oils. The composition of the fatty acids in the dietary fat

and tissue fats should be stated clearly, expressed as mol/100 mol or g/100 g total fatty acids.

Nomenclature of Micro-organisms. The correct name of the organism, conforming with

international rules of nomenclature, should be used: if desired, synonyms may be added in

parentheses when the name is first mentioned. Names of bacteria should conform with the

current Bacteriological Code and the opinions issued by the International Committee on

Systematic Bacteriology. Names of algae and fungi must conform with the current

International Code of Botanical Nomenclature. Names of protozoa should conform with the

current International Code of Zoological Nomenclature.

Nomenclature of Plants. For plant species where a common name is used that may not be

universally intelligible, the Latin name in italics should follow the first mention of the

common name. The cultivar should be given where appropriate.

Other Nomenclature, Symbols and Abbreviations. Authors should follow current numbers

of the British Journal of Nutrition in this connection. The IUPAC rules on chemical

nomenclature should be followed, and the Recommendations of the IUPAC-IUB Commission

on Biochemical Nomenclature (see Biochemical Journal (1978) 169, 11–14). The symbols

and abbreviations, other than units, are essentially those listed in British Standard 5775

(1979–1982), Specifications for Quantities, Units and Symbols, parts 0–13. Day should be

abbreviated to d, for example 7 d, except for ‘each day’, ‘7th day’ and ‘day 1’.

Elements and simple chemicals (e.g. Fe and CO

) can be referred to by their chemical

symbol or formula from the first mention in the text; titles can be taken as an exception. Well-

known abbreviations for chemical substances may be used without explanation, thus: RNA

110

for ribonucleic acid and DNA for deoxyribonucleic acid. Other substances that are

mentioned frequently may also be abbreviated, the abbreviation being placed in parentheses at

the first mention, thus: free fatty acids (FFA), and an alphabetical list of abbreviations used

should be included on a separate sheet of paper. Terms such as ‘bioavailability’ or ‘available’

may be used providing that the use of the term is adequately defined.

Spectrophotometric terms and symbols are those proposed in IUPAC Manual of Symbols

and Terminology for Physicochemical Quantities and Units (1979) London: Butterworths.

The attention of authors is particularly drawn to the following symbols: m (milli, 10

−3

), μ

(micro, 10

−6

), n (nano, 10

−9

) and p (pico, 10

−12

). Note also that ml (millilitre) should be used

instead of cc, μm (micrometre) instead of μ (micron) and μg (microgram) instead of γ.

Numbers. Figures should be used with units, for example, 10 g, 7 d, 4 years (except when

beginning a sentence, thus: ‘Four years ago...’); otherwise, words (except when 100 or more),

thus: one man, ten ewes, ninety-nine flasks, three times (but with decimal, 2·5 times), 100

patients, 120 cows, 136 samples.

Ethics of Human Experimentation. The notice of contributors is drawn to the guidelines in

the Declaration of Helsinki (1964) (British Medical Journal (1964) ii, 177–178), the Report of

ELSE as printed in British Journal of Nutrition (1973) 29, 149, the Guidelines on the Practice

of Ethics Committees Involved in Medical Research Involving Human Subjects (1990)

London: The Royal College of Physicians, and to the Guidelines for the Ethical Conduct of

Medical Research Involving Children, published in 1992 by the British Paediatric

Association, 5 St Andrew's Place, Regents Park, London NW1 4LB. A paper describing any

experimental work on human subjects should include a statement that the Ethical Committee

in the Institution in which the work was performed has approved it.

Animal Experimentation. The Editors will not accept papers reporting work carried out

using inhumane procedures. Authors should indicate that their experiments have been

approved by the appropriate local or national ethics committee for animal experiments.

Discloser of Financial Support. The source of funding should be identified either in the

experimental or acknowledgement section of the manuscript. All potential conflicts of

interest, or financial interests of the author in a product or company which is relevant to the

article, should be declared.

Proofs. PDF proofs are sent to authors in order that they make sure that the paper has been

correctly set up in type. Excessive alterations involving changes other than typesetting errors

may have to be disallowed or made at the author's expense. All corrections should be made in

ink in the margins: marks made in the text should be only those indicating the place to which

the corrections refer.

Corrected proofs should be returned within 3 days either by Express mail to the BJN

Production Editor, CABI Publishing, Wallingford, Oxon, OX10 8DE, UK; by fax +44 (0)

1491 833508 or via email [email protected].

Offprints. A copy of the issue and a PDF file of the paper will be supplied free of charge to

the corresponding author of each paper or short communication, and offprints may be ordered

on the order form sent with the proofs.

SUBMISSION PROCESS

The BJN now operates an on-line submission and reviewing system (eJournalPress).

Authors should submit to the following address: http://bjn.msubmit.net/. If any

difficulties are encountered please contact the Publications Office immediately.

111

The manuscript submission process is broken into a series of 4 screens that gather detailed

information about your manuscript and allow you to upload the appropriate text and

figure/table files. The sequence of screens is as follows:

1. A form requesting author details, manuscript title, abstract, and associated

information and the file quantities. Although there is the option of saving your

information and returning to complete your submission at a later date we strongly advise

you to submit your paper in one session if possible.

2. A screen asking for the actual file locations (via an open file dialogue). After

completing this screen, your files will be uploaded to our server.

3. A completion screen that will provide you with a specific manuscript number for your

manuscript. You may be asked to select the order in which your uploaded files should

be presented.

4. An approval screen that will allow you to verify that your manuscript has been

uploaded and converted to PDF correctly. Each converted file must be approved

individually to complete your online submission. If the conversion is not correct, you

can replace or delete your manuscript files as necessary. After you have reviewed the

converted files, you will need to click on "Approve Manuscript". This link will have a

red arrow next to it.

Throughout the system, red arrows reflect pending action items that you should address.

Before submitting a manuscript, please gather the following details for all authors:

• Title, First and Last Names

• Full Postal Address for Corresponding Author only

• Institutions

• Country

• Work Fax Number for Corresponding Author only (including international dialling

code)

• E-mail addresses

In addition we require full manuscript details:

Covering Letter

• Title (you may copy and paste this from your manuscript)

• Abstract (you may copy and paste this from your manuscript)

•

Manuscript files in PDF, Word, WordPerfect, or RTF format.

•

Ideally manuscript files should have the tables/figures given at the end of the article.

• For illustrations, preferred software packages are Adobe Illustrator, Adobe Photoshop,

Aldus Freehand, Chemdraw or CorelDraw. Preferred formats are TIFF or JPEG, if a

TIFF file is not possible save as an EPS or a windows metafile.

Please provide contact details for up to 4 potential Referees (email addresses and institutions).

For further information, please contact the Publications Office: Tel: +44 (0) 20 7371 6225

Fax: +44 (0) 20 7602 1756 Email: [email protected]

112

Anexo 3

Valores para peso de 1000 grãos e de macronutrientes das cultivares de feijão das safras 1 (2001/2002) e 2 (2002/2003)*

P 1000

grãos

Proteína

Bruta

Amido

Disponível

Amido

Resistente

Fibra

Total

Fibra

Solúvel

Extrato

Etéreo

Cultivar

1 2 1 2 1 2 1 2 1 2 1 2 1 2

TPS BONITO 234,00 233,00 22,81 22,73 33,08 33,78 4,70 4,41 24,74 25,11 4,55 7,59 1,42 1,01

TPS BIONOBRE 223,60 215,60 25,68 27,16 28,73 29,12 2,91 3,14 19,36 21,73 4,03 5,73 1,01 0,80

GUAPO BRILHANTE 211,20 230,40 24,16 23,14 35,61 39,41 3,00 3,56 20,60 20,25 4,61 3,86 1,48 1,90

TPS NOBRE 211,00 224,00 26,22 25,37 29,89 34,41 3,22 4,12 22,55 23,02 5,18 4,79 1,93 1,97

IRAÍ 320,80 339,40 21,24 22,50 29,72 31,97 3,18 3,20 22,95 26,06 3,61 6,45 1,35 0,87

FTS SOBERANO 157,60 205,00 29,06 24,62 33,40 38,90 2,99 3,29 19,44 22,58 3,44 3,85 1,56 1,95

GUATEIAN 6662 185,40 189,40 27,45 27,96 33,25 34,02 2,91 2,98 21,05 21,20 9,18 6,43 1,41 1,42

CARIOCA 260,40 259,60 25,44 24,93 35,06 32,12 3,20 3,13 21,38 20,32 7,22 3,68 1,23 1,25

RIO TIBAGI 180,60 151,80 28,95 27,52 27,10 28,06 3,59 3,47 19,25 22,29 4,99 7,51 1,74 1,57

MINUANO 215,60 214,00 23,82 24,52 32,98 28,90 3,55 3,80 22,92 28,01 3,14 8,53 1,53 1,31

PÉROLA 264,80 282,40 26,97 26,09 23,46 29,28 4,56 4,20 20,32 20,77 3,31 1,26 1,44 1,22

FTS MAGNÍFICO 235,80 261,80 26,75 25,84 28,36 29,35 3,98 4,58 21,16 20,12 3,71 2,32 4,77 3,88

MACANUDO 212,80 223,40 23,42 24,73 29,04 25,99 2,35 2,57 20,23 18,41 4,22 2,35 0,85 1,36

DIAMANTE NEGRO 217,80 207,80 27,79 26,27 20,02 23,66 2,54 2,47 19,91 21,28 3,22 5,86 1,62 1,51

VALENTE 203,40 191,60 26,66 24,68 21,56 25,46 2,62 2,46 18,09 20,90 3,81 6,02 1,67 2,26

IAPAR 31 222,40 252,20 24,66 23,70 29,07 28,50 4,18 3,61 18,40 21,08 3,38 5,26 1,33 1,15

Média

222,33 230,09 25,69 25,11 29,39 30,81 3,34 3,44 20,77 22,07 4,47 5,09 1,65 1,59

CV (%)

16,96 18,78 8,62 6,53 15,71 14,55 20,97 19,29 8,70 11,15 36,29 40,70 53,00 46,36

*Valores (média de 3 repetições) expressos em g/100 g de MS.

113

Anexo 4

Valores de micronutrientes das cultivares de feijão das safras 1 (2001/2002) e 2 (2002/2003)*

Cultivar

1 2 1 2 1 2 1 2 1 2 1 2 1 2

TPS BONITO 9,56 9,37 3,53 3,55 1,50 1,54 1,47 1,36 117,39 117,52 23,98 21,82 274,80 337,42

TPS BIONOBRE 8,83 10,57 3,40 3,38 1,65 1,66 1,56 1,51 361,34 426,37 24,47 22,75 294,47 349,70

GUAPO BRILHANTE 8,39 9,42 3,28 3,51 1,47 1,47 1,38 1,51 343,32 333,80 22,77 23,26 338,47 355,31

TPS NOBRE 10,11 n.d. 4,02 3,46 1,92 1,71 1,43 1,57 394,29 427,24 23,96 24,84 350,75 329,52

IRAÍ 7,50 8,85 4,02 2,72 1,51 1,30 1,17 1,18 325,84 349,92 17,60 20,80 365,96 374,26

FTS SOBERANO 9,30 10,52 3,74 3,69 1,80 1,63 1,48 1,60 351,71 346,09 24,93 24,80 375,18 360,32

GUATEIAN 6662 9,96 9,88 3,21 3,34 1,83 1,58 1,68 1,89 429,75 468,63 26,73 26,03 392,87 348,00

CARIOCA 8,89 9,97 2,81 3,33 1,37 1,58 1,30 1,28 406,34 422,54 24,62 24,36 376,14 379,01

RIO TIBAGI 9,12 10,32 3,59 3,69 1,45 1,56 1,59 1,86 411,55 426,29 24,78 22,50 304,98 291,84

MINUANO 8,68 9,77 3,29 3,20 1,42 1,40 1,45 1,54 328,41 404,99 23,45 24,85 329,17 328,94

PÉROLA 9,04 10,17 3,29 3,90 1,53 1,56 1,52 1,54 406,63 402,98 25,90 24,65 346,11 349,86

FTS MAGNÍFICO 9,25 9,72 3,47 3,36 1,84 1,83 1,50 1,42 380,64 395,97 24,87 24,68 354,17 325,62

MACANUDO 6,36 9,49 2,91 3,39 1,12 1,43 1,22 1,35 348,01 163,12 22,82 22,26 339,10 333,62

DIAMANTE NEGRO 8,76 9,58 3,76 3,52 1,51 1,53 1,46 1,55 138,39 171,02 23,52 23,44 343,10 369,13

VALENTE 9,62 9,46 3,72 3,62 1,63 1,61 1,41 1,49 163,16 174,53 24,14 22,22 353,91 335,77

IAPAR 31 9,55 8,44 3,19 3,09 1,51 1,33 0,84 0,90 156,33 200,15 22,92 22,76 369,33 369,25

Média

8,93 9,70 3,45 3,42 1,57 1,55 1,40 1,47 316,44 326,95 23,84 23,50 344,28 346,10

CV (%)

10,44 6,01 10,14 7,99 13,11 8,88 14,15 16,17 34,03 36,27 8,32 6,08 9,13 6,47

*Valores (média de 3 repetições) expressos em g/100 g de MS.

n.d. = não determinado.

Livros Grátis
( http://www.livrosgratis.com.br )
 
Milhares de Livros para Download:
 
Baixar livros de Administração
Baixar livros de Agronomia
Baixar livros de Arquitetura
Baixar livros de Artes
Baixar livros de Astronomia
Baixar livros de Biologia Geral
Baixar livros de Ciência da Computação
Baixar livros de Ciência da Informação
Baixar livros de Ciência Política
Baixar livros de Ciências da Saúde
Baixar livros de Comunicação
Baixar livros do Conselho Nacional de Educação - CNE
Baixar livros de Defesa civil
Baixar livros de Direito
Baixar livros de Direitos humanos
Baixar livros de Economia
Baixar livros de Economia Doméstica
Baixar livros de Educação
Baixar livros de Educação - Trânsito
Baixar livros de Educação Física
Baixar livros de Engenharia Aeroespacial
Baixar livros de Farmácia
Baixar livros de Filosofia
Baixar livros de Física
Baixar livros de Geociências
Baixar livros de Geografia
Baixar livros de História
Baixar livros de Línguas

Baixar livros de Literatura
Baixar livros de Literatura de Cordel
Baixar livros de Literatura Infantil
Baixar livros de Matemática
Baixar livros de Medicina
Baixar livros de Medicina Veterinária
Baixar livros de Meio Ambiente
Baixar livros de Meteorologia
Baixar Monografias e TCC
Baixar livros Multidisciplinar
Baixar livros de Música
Baixar livros de Psicologia
Baixar livros de Química
Baixar livros de Saúde Coletiva
Baixar livros de Serviço Social
Baixar livros de Sociologia
Baixar livros de Teologia
Baixar livros de Trabalho
Baixar livros de Turismo
 
 