Effects of ultrasonic enhancement on physicochemical properties, structural, antioxidant activity and potential antidiabetic effect of asparagus juice

Ultrasonic enhancement has a significant effect on improving the nutrient dissolution, antioxidant activity and hypoglycemic effect of asparagus juice (AJ), which is an efficient green technology to improve the quality of AJ. In this study, AJ was prepared by no-processing (NP), blanching (BA), freeze-thaw (FT), microwave (MW) and ultrasonic (US), and its nutritional content, structural characteristics, antioxidant activity, α -glucosidase and α -amylase inhibitory activity were analyzed. The results showed that ultrasonic treatment not only increased the juice yield of asparagus (increased by 27.61 %, P < 0.05), soluble solid content (increased by 17.07 %, P < 0.01), and improved its color properties, but also significantly improved the dissolution of a variety of nutrients. In addition, ultrasonic treatment changed the microstructure of AJ, reduced the particle size and molecular weight of AJ, improved the uniformity of AJ, and enhanced the antioxidant activity of AJ against four free radicals. Correlation analysis showed that the increase of nutrient content and structural changes after ultrasonic treatment were closely related to the improvement of antioxidant activity. In the study of the potential diabetes inhibitory effect of AJ, the ultrasonic enhanced AJ had the highest inhibitory activity on α -glucosidase and α -amylase. In addition, the enzyme inhibition kinetics showed that AJ exhibited irreversible competitive inhibition of α -glucosidase and α -amylase activity. • Ultrasonic treatment promoted the dissolution of nutrients in Asparagus. • Ultrasonic treatment made the microstructure of asparagus juice (AJ) more uniform. • Ultrasound enhanced the antioxidant activity of AJ. • Ultrasound enhanced the inhibitory activity of AJ on α -glucosidase and α -amylase. • AJ is an irreversible competitive inhibition of α -glucosidase and α -amylase.