Características físico-químicas de derivados proteicos de soja em dietas extrusadas para cães.

Soy is a grain rich in protein and lipids, from which its obtained different protein products of high nutritional value. This study aimed to analyze the chemical composition of different soy-protein products, as well as the characteristics of the extruded produced. Six diets were formulated, a reference and five with 30% soy product (defatted soy flour - DSF, micronized, soybean meal, crude grain or toasted grain), which were extruded. Soy products and diets were submitted to chemical analyses and process quality. The DSF and soybean meal presented the highest crude protein content, while the toasted and crude soybeans and micronized soy presented the highest acid hydrolyses ether extract and crude energy content. The crude soybean presented the highest ureatic activity and trypsin inhibitor activity, even after the diet extrusion. The soy beans and micronized soy extruded presented the highest density and the lowest hardness, water absorption index and starch gelatinization degree. Soy-protein products present high nutritional value, however they should be heated before extrusion to complete inhibition of trypsin inhibitor. Besides, soy products with high fat content, such as soybean and micronized soybean, when added to 30% reduced the extruded quality. [ABSTRACT FROM AUTHOR]