Chemical characterization and size distribution of sorghum genotypes for human consumption

The purpose of this paper was to evaluate the approximate composition, size distribution, minerals and vitamin E isomers concentrations in eight sorghum geno types available for human consumption. The protein concentration of samples ranged from 8.57 to 11.59%, lipids from 1.24 to 3.07% and carbohydrates from 57.3 to 64.7%. The total dietary fiber varied from 9.13% to 15.09%. Sorghum genotytes flours were characterized as hard grain and of coarse granulometry, which are the relevant aspects for developing food products. Soghum genotypes were considered as sources of iron, phosphorus, magnesium and zinc. The áand ã-tocopherol isomers were determined in sorghum genotypes grain and flour, and ã-tocopherol was predominant. In conclusion, sorghum genotypes evidenced to be as relevant sources of dietary fiber, iron, phosphorus, magnesium and zinc. Furthermore, the sorghum genotypes were classified as hard grain ,suitable for formulating bakery products.

Qualidade proteica e eficiência alimentar de farinhas integrais de linhaça obtidas de sementes cruas e submetidas a tratamento térmico / Protein and food qualities of brown flaxseed whole flour from the raw and heat–treated seeds

A linhaça é uma oleaginosa que desperta interesse pelo seu alto teor de compostos bioativos e proteínas, embora pouco se saiba sobre as possíveis interferências desses compostos na sua qualidade proteica. Neste estudo foram avaliadas a qualidade proteica e a concentração de compostos fenólicos e de fibra alimentar em farinhas integrais de linhaça marrom crua e submetida ao tratamento térmico (150oC por 15 minutos). A qualidade proteica foi analisada em ratos Wistar recém-desmamados. Houve aumento de 2,4% no teor de fenólicos totais e redução de 10% e 80%, respectivamente, nos teores de hexafosfato e pentafosfato demioinositol, quando a semente foi exposta ao tratamento térmico. O ganho de peso dos animais, o Coeficientede Eficiência Alimentar, o Coeficiente de Eficiência Proteica e a Razão Proteica Líquida foram menores nos animais alimentados com dietas contendo linhaça, em comparação à caseína, porém, o tratamento térmico não interferiu na qualidade proteica da linhaça. Estudos futuros poderão esclarecer se o tratamento térmico utilizado não foi suficiente para inativar os fatores antinutricionais que afetam a digestibilidade das proteínas desse alimento.

Flaxseed is an oilseed that arises concerns for its high contents of bioactive compounds and proteins,although little is known about the presumable interference of these compounds in its protein quality. Thisstudy evaluated the protein quality, and the concentration of phenolic compounds and of dietary fiber inraw and heat-treated (150oC for 15 minutes) brown flaxseed whole flour. The protein quality was analyzedin weaned Wistar rats. When the seeds were exposed to heat treatment, an increase of 2.4% in the totalphenolic contents and reductions of 10% and 80% were observed in the myo-inositol hexaphosphate andpentaphosphate contents, respectively. The weight gain of animals, the Food Efficiency Ratio, the ProteinEfficiency Ratio and the Net Protein Ratio were lower in animals fed with flaxseed-containing diets,when compared with the casein diet, however the heat treatment did not affect the protein quality offlaxseed. Further studies might clarify whether the used heat treatment was not sufficient to inactivate theantinutritional factors that affect the protein digestibility of this food.