The influence of different physical pretreatments on the enzymatic hydrolysis effect and flavor characteristics of high-temperature soybean meal

In order to explore the characteristics of different physical pretreatment, this study focused on the effects of ultrasound (UP), microwave (MW), high-pressure heating (HPH) and mechanical milling (MM) pretreatment on the enzymolysis effect and flavor characteristics of high-temperature soybean meal. The enzymatic hydrolysis efficiency of HPH group was the highest, with the highest hydrolysis degree (24.01 ± 0.15 %), the highest soluble peptide content (15.69 ± 0.16 mg/mL) and the highest content of components <180 Da (16.09 ± 0.22 %). MW group had the highest content of umami and sweet amino acids (619.94 mg/100 mL) and the strongest antioxidant capacity. MW group not only had better umami but the bitterness of HPH group was the most obvious. In addition, MW promoted the formation of pleasant volatile compounds such as esters, and reduced the content of 1-octene-3-alcohol. Generally speaking, MW is an effective technology to improve the enzymatic hydrolysis performance and flavor characteristics of high-temperature soybean meal.