Caracterização do amido de grão-de-bico (Cicer arietinum L.).

O objetivo deste trabalho foi extrair e caracterizar o amido de grão-de-bico quanto a sua composição química, estrutural e morfológica, propriedades térmicas e tecnológicas. O rendimento apresentado no processo de extração foi de 28%, com alta pureza. A observação em microscopia eletrônica de varredura mostrou grânulos de amido com formato cilíndrico e oval, com dimensões de 20 µm de comprimento e 10 µm de largura. O padrão de cristalinidade mostrado por difratometria de raios X foi do tipo C, típico de leguminosas. A análise das propriedades de pasta foi efetuada por calorimetria diferencial de varredura (DSC) e analisador rápido de viscosidade (RVA). Em DSC, foi encontrada a temperatura inicial de gelatinização de 65,51°C, a final de 86,90°C e a entalpia de gelatinização de 12,12 J/g. O RVA mostrou temperatura inicial de gelatinização de 73,1°C, valores elevados de viscosidade, baixa quebra e alta tendência à retrogradação. O amido apresentou pouco inchamento e solubilidade, mesmo na temperatura de 90°C. O gel de amido de grão-de-bico mostrou-se turvo e com alta sinérese e apresentou elevada dureza e elasticidade em análise de perfil de textura

Elaboração e digestibilidade in vitro do amido de farofa pronta à base de farinha de sorgo (Sorghum bicolor (L.) moench).

O sorgo é um cereal rico em compostos fenólicos, não possui glúten e possui baixa digestibilidade do amido. O objetivo deste trabalho foi avaliar a digestibilidade in vitro do amido de farofas prontas para consumo formuladas a partir de farinhas de sorgo com e sem taninos e de mandioca acrescidas dos mesmos ingredientes. As concentrações de amido rapidamente digerível (ARD), lentamente digerível (ALD) e resistente (AR) das amostras foram determinadas. A farofa de mandioca apresentou maior concentração de ARD (64,7%) e ALD (29,9%) e a menor concentração de AR (0,6%) entre as farofas avaliadas. Já as amostras de sorgo com e sem taninos apresentaram valores mais baixos de ARD (26,4% e 30,6%, respectivamente) e ALD (5,2% e 5,6%, respectivamente), porém, valores maiores de AR (21,4% e 7,6%, respectivamente) quando comparados às farofas de mandioca. Estes resultados encontrados para a farofa pronta de sorgo com taninos apontam este produto como uma excelente alternativa de substituição de um produto popularmente consumido por um produto à base de sorgo, saudável, rico em fibras e antioxidantes

Mixed sorghum and quinoa flour improves protein quality and increases antioxidant capacity in vivo.

Quinoa is a pseudocereal that has high protein quality and sorghum has phenolic compounds that give it a higher antioxidant capacity, however, its protein quality is low. Thus, this study aimed to evaluate the effect of the obtaining mixture of sorghum and quinoa flours on protein quality and antioxidant capacity in Wistar rats. The animals were allocated into five groups (n = 8): protein-free, control (casein) and experimental groups: sorghum flour, quinoa flour, and mixed sorghum/quinoa flour. At 21 days of the experiment, animals from the control and experimental groups received sodium fluoride (NaF) water for seven days to induce oxidative stress. The groups fed with sorghum, quinoa, and mixed flour sorghum/quinoa had, respectively, PER values of 0.23, 2.0, 1.5; NPR 1.82, 3.36, 2.88 and TD 60.22, 81.46, 66.82 and weight gain 1.75, 20.84 and 15.92. The total antioxidant capacity of serum increased in sorghum and mixed sorghum/quinoa flour groups, probably due to the higher amount of phenolic compounds. There was no change in the activities of the antioxidant enzymes superoxide dismutase, catalase, and the biomarker malondialdehyde. Thus, the mixed flour of sorghum/quinoa is an excellent alternative for the elaboration of products with better protein quality and high antioxidant capacity

Efeito do armazenamento sobre as propriedades tecnológicas da farinha, de variedades de trigo cultivadas no Brasil Effect of storage on technological properties of wheat flour of Brazilian grown wheats

<abstract language="eng">The aim of this work was to evaluate changes in technological properties of newly milled flours of BR-23, BR-35 and Anahuac varieties (Brazilian grown wheat) during storage for 180 days. Quality of samples was analysed for their rheological properties, acidity, falling number, glutomatic test and baking test, after periods of 0, 7, 15, 30, 60, 90, 120, 150 and 180 days. Most evident changes were the increase in flour acitidy and dough elasticity. The other characteristics did not show expressive changes. The flour of Anahuac variety was less influenced by the storage than the other ones. The results showed an increment in the flour quality, during 60-90 days of storage, althoug the baking test did not show expressive changes during all the period of storage

A second 'overexpression' allele at the Glu-B1 high-molecular-weight glutenin locus of wheat: sequence characterisation and functional effects

Bread is one of the major constituents of the human diet and wheat (Triticum aestivum L.) is the most important cereal for bread making. The gluten proteins (glutenins and gliadins) are recognised as important components affecting the processing quality of wheat flour. In this research, we investigated a particular glutenin subunit allele in an Australian cultivar, H45. Based on protein and DNA assays, the Glu-B1 allele of H45 seems to be Glu-B1al, an allele that includes a functional duplication of a gene encoding an x-type high-molecular-weight glutenin subunit, and is thought to increase dough strength through overexpression of that subunit. Yet H45 does not have the dough properties that would be expected if it carries the Glu-B1al allele. After confirming that H45 overexpresses Bx subunits and that it has relatively low un-extractable polymeric protein (an indicator of weak dough), we cloned and sequenced two Bx genes from H45. The sequences of the two genes differ from each other, and they each differ by four single-nucleotide polymorphisms (SNPs) from the sequence that has been reported for the Glu-B1al x-type glutenin genes of the Canadian wheat cultivar Glenlea. One of the SNPs leads to an extra cysteine residue in one of the subunits. The presence of this additional cysteine may explain the dough properties of H45 through effects on cross-linkage within or between glutenin subunits. We propose that the Glu-B1 allele of H45 be designated Glu-B1br, and we present evidence that Glu-B1br is co-inherited with low un-extractable polymeric protein.Xin Gao, Marie J. Appelbee, Genet T. Mekuria, Kenneth J. Chalmers, Diane E. Mathe