Preparation of hypoglycemic anthocyanins from mulberry (Fructus mori) fruits by ultrahigh pressure extraction

In this study, mulberry anthocyanins were extracted by ultrahigh pressure extraction (UPE) and investigated on biological activities. Based on response surface methodology (RSM), the optimum conditions were 430 MPa of extraction pressure, 75% v/v ethanol concentration, 12:1 v/w liquid-solid ratio, the highest extraction yield was 1.97 ± 0.11 mg/g. Six anthocyanins were identified by ultrahigh performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MSE). The antioxidant activity of anthocyanins was determined by reducing powder, the scavenging of hydroxyl radical and 2,2-diphenyl−1-picrylhydrazyl (DPPH) free radical activity. In addition, the α-glucosidase and α-amylase inhibitory rate of mulberry anthocyanins rose in a dose-dependence manner. When anthocyanin concentration is 0.50 mg/mL, the highest inhibition percentage is 65.51% and 81.72%, respectively. The high temperature, high pH and outdoor light will affect the inhibitory ability of enzyme. These findings could provide optimal extraction methods and provide perspective for mulberries anthocyanins using in functional food.