Effects of Soybean Endogenous Enzyme Hydrolysis on the Quality of Soymilk after Blanching

This study examined the relationship between the endogenous enzymatic hydrolysis conditions and the quality and flavor of soymilk derived from blanched soybeans. Results represented that following blanching, the lipoxygenase activity of soybeans decreased by 88.50% and the endogenous protease activity greatly improved compared to unblanched. During the subsequent endogenous enzymatic hydrolysis, the stability factor and sensory score dropped as the amount of okara rose, although the content of peptides and amino acids nitrogen increased. At an enzymolysis temperature of 50 °C, the soymilk had the highest sensory score. After 60 min of enzymolysis, the beany odor was weakened maximumly; the levels of polypeptide and amino acid nitrogen increased by 45.00% and 43.33%, respectively. Enzymatic hydrolysis at 50 °C for 60 min without okara generated the finest soymilk. Blanching diminished the primary components of the beany odor of raw soymilk. Enzymolysis of blanched pretreatment soymilk further dropped the content of beany odor components and exhibited a richer variety and concentration of volatile components. Following the hydrolysis of endogenous enzymes generated after blanching, the overall quality of soymilk was enhanced.