Biodisponibilidade de zinco e de ferro, valor nutricional e funcional de diferentes cultivares de feijão comum submetidos a tratamentos domésticos

• Ano de defesa: 2006
• Autor(a) principal: Ramírez Cárdenas, Lucía de Los Angeles
• Orientador(a): Costa, Neuza Maria Brunoro
• Banca de defesa: Gomes, José Carlos , Oliveira, Maria Goreti de Almeida , Soares, Nilda de Fatima Ferreira , Bassinello, Priscila Zaczuk
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Ciência e Tecnologia de Alimentos
• Departamento: Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
• País: BR
• Palavras-chave em Português: Feijão; Composição; Ferro; Zinco; Biodisponibilidade; Colesterol; Diabetes
• Palavras-chave em Inglês: Common bean; Composition; Iron; Zinc; Bioavailability; Cholesterol; Diabetes
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/411

The common beans (Phaseolus vulgaris, L.) is an important source of proteins, starch, vitamins, minerals and dietary fiber in the Brazilian diet. The bioavailability of its minerals, however, may be affected either by the cooking process or by the presence of antinutrient factors. The antinutrients are reported to have both positive and negative effects to human health. This study evaluated the nutrition facts, the bioavailability of zinc and iron and the functional properties of 5 cultivars of beans: white (Ouro Branco), black (Diamante Negro) and brown-rajado (BRS Radiante, Pérola and Talismã). The centesimal composition and the contents of minerals, tannins and phytate were evaluated in flours made by raw beans as well as in beans cooked without soaking; cooked with the soaking water or cooked without the soaking water. The contents of total, soluble and insoluble dietary fiber and the amino acid profile were analyzed in beans cooked with the soaking water. All the parameters analyzed varied with the bean cultivar. The cooking process affected only the contents of tannins and phytate, which were both reduced to a higher extent by cooking without the soaking water. The cooking process increased the content of insoluble dietary fiber and decreased the soluble dietary fiber when compared to the raw samples. Based on the protein digestibility corrected amino acid score (PDCAAS). Pérola was the cultivar with lowest protein quality and Talismã the highest one. To evaluate the zinc bioavailability, weaning rats were fed their experimental diets (Standard or beans cooked with or without soaking water), containing 15mgZn/kg diet for 28 days. The levels of plasma and erithrocyte zinc, the bone size and bone mineral composition were evaluated. Zinc bioavailability was not affected by the cooking process but depended on the cultivar. The white bean diet (Ouro Branco) showed the highest bioavailability and the brown bean diet (Talismã) cooked with the soaking water the lowest values. To evaluate the iron bioavailability, weaning rats were placed in an iron-free diet for 21 days (depletion). Then, they were assigned to their experimental diets (control or 5 cultivars of beans cooked with the soaking water), containing 6, 12 or 24 mg Fe/kg diet for 14 days (repletion). The hemoglobin gain and hematocrit were evaluated in function of the iron content of the diets. The white bean diet (Ouro Branco) showed the highest iron bioavailability and the brown bean diet (BRS Radiante) the lowest values. The functional properties of the bean cultivars were evaluated in adult rats, divided into 7 groups; one control (Normal); one with high fat and sucrose diet (HFS) and 5 other groups fed HFS diet added with 30% beans cooked with the soaking water, for 28 days. Feces were collected from day 21 to 24 and at the end of the experiment; the animals were sacrificed for blood and liver sampling. The black cultivar (Diamante Negro) showed better hypocholesterolemic effect; the brown bean (BRS Radiante) promoted the highest blood glucose lowering effect. The white cultivar (Ouro Branco) showed the least hypocholesterolemic effect and no blood glucose reduction. Zinc bioavailability was not associated to the contents of tannins, dietary fiber and phytate, but was affected by the phytatexcalcium:zinc milimolar ratios of the bean cultivars. Iron bioavailability was associated to the content of tannins, but not to the contents of dietary fiber, phytate and the phytate:iron milimolar ratio. The functional properties were not associated to the phytate content and amino acid profile, but depended on the contents of tannins and soluble and insoluble dietary fiber of the bean cultivars. These results should be considered for dietary planning to overcome nutritional problems. Therefore, the Talismã cultivar may be recommended if the protein quality is searched. For zinc and iron deficiencies, Ouro Branco cultivar should be chosen. Cooking without the soaking water is the preferred process to reduce the levels of antinutrients and to improve the mineral bioavailability, although such effect depends on the bean cultivar. For better functional properties, the indicated cultivars are Diamante Negro (black) and BRS Radiante (brown). In any case, the beans contribute to a high-quality diet and should be encouraged to increase its consumption in the Brazilian diet.