Ultrasound-Assisted Enzymatic Extraction of Mangiferin From Mango (Mangifera indica L.) Peels: Process Optimization and Antioxidant Activity Evaluation.

Mango peel is one of the main byproducts in mango processing. In order to improve the utilization and added-value of mango peel, effects of the ultrasound-assisted enzymatic method on the extraction rate of mangiferin from mango peel were investigated by single-factor tests (enzyme addition amount, enzymolysis time, ethanol concentration, ultrasonic temperature, ultrasonic power, and ultrasonic time), and the extraction process was optimized by Box-Behnken response surface. The antioxidant activity and antidiabetic assay of mangiferin in vitro were studied. The results showed that enzymolysis time 44 min, enzyme addition amount 0.1%, ethanol concentration 70%, ultrasonic power 300 W, ultrasonic temperature 66°C, and ultrasonic time 45 min were the optimal extraction process parameters. Under these conditions, the extraction rate of mangiferin was 3.63% ± 0.04%, which was not significantly different from the model prediction value (3.71%), and it was 3.90 times and 1.78 times that of single cellulase and ultrasonic extraction, respectively. Within the test concentration range, the scavenging rate of mangiferin for DPPH·, ABTS+·, and O2 -· increased with the increase of its mass concentration, and the EC50 values were 0.03829 mg/mL, 0.06032 mg/mL, and 0.04949 mg/mL, respectively, which were slightly higher than those of Vc. Meanwhile, mangiferin exhibited inhibitory activity effects on α-amylase and α-glucosidase, with IC50 values of 0.1952 and 0.08696 mg/mL, respectively. Results indicate that the mangiferin in mango peel had strong bioactivity. The study provides a theoretical reference for the efficient extraction of mangiferin from mango peel and provides a scientific basis for further realizing the high-value utilization of mango processing waste.