Efeito da temperatura de extrusão, umidade da materia-prima, teor de amido e sacarose nas caracteristicas tecnologicas e nutricionais de produtos extrusados de germe de trigo

AUTOR(ES)
DATA DE PUBLICAÇÃO

1992

RESUMO

Wheat germ component is rich in vitamins, minerals, fat content and good quality proteins. The amount of wheat germ used as food in human consumption is very low compared to the amount used as feed for animal. This fact could be explained by some problems in raw wheat germ. The extrusion cooking process - High Temperature Short Time was applied to wheat germ in order to obtain a product for human consumption. The objectives of this study were to analyze the effects of the extrusion temperature (90 to 210°C), moisture content of the raw material (15 to 23%), starch content (25 to 457.) and sugar content ÍO to 16%}, over some technological characteristics of the products and to conduct a nutritional quality evaluation and stability of the final product under the following conditions; temperature of the extrusion process varying from 107,6 a 192,4°C and moisture content from 16,2 a 21,8%. Response surface analysis was used in order to analysis the date obtained. The analysts of the results showed that water absorption, solubility, force necessary to crunch and density were statistically significant affected by the temperature of the extrusion and by the moisture content as well as by variation in starch and sugar contents. Expansion was not affected by moisture content. It is interesting to observe that products that have the same value for one property can be obtained under different extrusion conditions. The extruded product showed a good nutritional value when compared to raw wheat germ and casein, based upon digestibility, biological value, net protein utilization and net protein ratio. The temperature extrusion was the most significative factor that affect such results. Vitamins were affected by extrusion temperature and moisture content. The shear and the high temperature were founded to be the factors responsible for the destruction of the vitamins. The process under study showed a substantial loss of vitamin E and greater retention of pyridoxin. The peroxide index was determined during storage with the temperature of extrusion, with increasing temperature until approximately 55°C. The index of acidity was determined soon after extrusion with condition of extrusion. Less values were found with lower moisture and with temperatures higher than 160°C. This condition coincides with lower Upases activity. By sensorial analysis the estruded product were rejected due rancid odor, after a storage période of approximately 100 days.

ASSUNTO(S)

trigo - produtos germen de trigo

ACESSO AO ARTIGO

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