Effect of microwave combined with ultrasonic pretreatment on flavor and antioxidant activity of hydrolysates based on enzymatic hydrolysis of bovine bone

Protein from bovine by-products can be hydrolyzed into amino acids, and then react with reducing sugar to prepare meat flavor. The effects of microwave (3min, 6min) and ultrasonic (600W, 900W, 1200W) on the hydrolysis degree, antioxidant activity, and flavor characteristics of the hydrolysate of bovine bone protease were studied. The microwave treatment combined with 1200W ultrasonic (MW6-US1200) treatment has the highest hydrolysis degree. Before enzymolysis, after MW6-US900 and MW6-US900 treatment, the fresh and salty taste increased, the astringency decreased, and the flavor components such as aldehydes, ketones and lipids also increased. MW6-US900 group had the highest antioxidant activity. In conclusion, microwave combined with ultrasonic (MU) can improve the enzymatic hydrolysis effect of protein in beef bone meal, improve the antioxidant performance and flavor of the hydrolysate. • Combination of microwave and ultrasonic for pretreatment of bovine bone proteolysis. • Effect of pretreatment on water distribution and degree of hydrolysis of sample was studied. • Effects of pretreatment on the oxidation resistance and degree of hydrolysis of hydrolysates were studied. • The flavor and free amino acids of hydrolysates were analyzed.