Study on ultrasonic extraction and antioxidant activity of rutin from sophora japonica

The optimum condition for rutin from sophora japonica of extraction assisted with ultrasonic wave was studied by the orthogonal design mode.Its antioxidant activity was analysed using super oxide anion radical method.The result showed that the optimal extracting conditions were as follows:extracion solvent 60% ethanol, ratio of solvent to solute (v/w) 10, extracion temperature 45℃, and extraction time 30min.There were good relationship between contents of rutin and activities of scavenging hydroxyl free radical, superoxide anion free radical and DPPH radical and appeared linear relationships.The abilities of scavenging DPPH radical and superoxide anion free radical were stronger, the IC50 were 28.39μg/mL and 69.88μg/mL, respectively.When adding the antioxidant, stability of red peppers haematochrome was improved.Compared with VC, VE and BHT, rutin was superior to VE and BHT and next to VE.