Study on effect of temperature on soybean antioxidative peptides prepared by solid-state fermentation and hydrolysis

The objective of this study was to evaluate the effect of temperature on the efficiency of hydrolysis,antioxidant activity and flavor characteristics of soybean peptides prepared by soybean meal solid- state fermentation and hydrolysis. Results showed that,with the increasing temperature,hydrolysis efficiency gradually decreased. Koji treated by homogeneous process had better hydrolysis efficiency. Homogeneous process at45 ℃ resulted in the maximum hydrolysis efficiency. Under this conditions the total nitrogen,ammonia nitrogen,DH,protein recovery of hydrolyzates were 1.08%,0.55%,50.64%,64.25%,respectively. The highest DPPH radical scavenging activity and reducing capability of koji hydrolysate were observed at 45 ℃ without homogeneous process,which were 85.8% and 1.71 times of those of GSH. The highest ABTS radical scavenging activity was achieved at 50 ℃ with homogeneous process,which was 1.22 times of that of GSH.Sensory evaluation of hydrolysates with higher antioxidant activity in umami,savory and aftertaste showed that hydrolysate at 45 ℃ without homogeneous process had a better score in three aspects and that at 50 ℃ with homogeneous process had the highest umami score,6 points.