Microwave-assisted extraction technology optimization and antioxidative effect of polyphenols from Polygonatum odoratum

According to previous study of single variable test, an ultrasonic procedure for the extraction of Polygonatum odoratum ( Mill.) Druc polyphenols was established.A three- level- four- factor, Box- Behnken design ( BBD) of response surface methodology was employed in this study to optimize the factorial parameters ( micromave power, microwave time, ratio of solvents to raw material, and ethanol concentration) , and polyphenols yield was taken as the response of the design experiments. The scavenging rates of 1, 1- diphenyl- 2- picryl-hydrazil ( DPPH) radical and superoxide anion of P. odoratum polyphenols in vitro were determined. The results showed that optimal extraction conditions for extraction of P.odoratum polyphenols were found to be microwave power 329 W, microwave time 26 min, ratio of solvents to raw material 1∶34 ( g /mL) , and ethanol concentration 49%, respectively.Under these conditions, the yield of P.odoratum polyphenols was 67.40 mg /g.P.odoratum polyphenols showed excellent scavenging effect against DPPH radical and superoxide anion in vitro.The study revealed that microwave-assisted technology was suitable for extraction of P.odoratum polyphenols, which was simply and high efficient, and the regression model was reliable for yield prediction.Moreover, P.odoratum polyphenols extracted by this method exhibited strong antioxidant activity in vitro.