Ultrasonic extraction of flavonoids from sweet potato(Ipomoea batatas (L.) lam) leaves
flavonoids from sweet potato leaves(SPLF) were extracted by ultrasonic technology,and the extraction conditions were optimized by uniform design.Also,ethanol concentration,liquid-solid ratio and ultrasonic time were visited on the effects of SPLF yield,then the SPLF were analyzed by HPLC-DAD.The results showed that the extract of sweet potato leaves with ultrasound and no ultrasound had similar characteristic absorption bands I and II,the relative intensity of the absorption peak also had the characteristics of flavonoids.Through DPS7.05 software,with secondary regression analysis,the best extraction conditions were as follows: ethanol concentration 63.56%,liquid-solid ratio 46.26 mL/g,ultrasonic time 15 min,under the optimum conditions,the flavonoids yield was 5.48%.