Oxidative Stability of Dried Model Food Consisted of Soybean Protein Hydrolyzate and Lard

Abstract

Soybean protein was hydrolyzed by 9 kinds of pretease preparations to the extent of 3.7-17.7% and used as constituents of the dried model food. The most effective antioxidative activity was found in the 17.7% hydrolyzed fraction. When soybean protein was hydrolyzed by Enzyme No.4 protease at various degrees, it was found that the higher was the hydrolysis degree, the stronger antioxidative activity was detected. The soybean protein hydrolyzates above 17% of the degree was found to decompose hydroperoxides of fat and oil. The oxidative stability of the dried model food was improved by adding soybean protein hydrolyzate above 3% level. Furthermore, synergistic effect of soybean protein hydrolyzate with d-δ-tocopherol was observed.