Polyphenols extraction methods from persimmon pomace and its antioxidant activity.

With the content of total polyphenols as the indication,single-factor experiments with different ratios of solid to liquid,temperatures,ethanol concentrations and time were studied.The best extraction technology of total polyphenols were optimized by the orthogonal experiment.The antioxidant activity of persimmon pomace extract were measured with DPPH· method.The results showed that:extract temperature and extract time had a significant effect on the content of total polyphenols,but ethanol concentration and the ratio of solid to liquid had no distinct effect.The optimum extracting conditions are solid-liquid ratio (V:W) 20:1,temperature 90℃,ethanol concentration 40%,time 4 h;The validation experiment result indicates that:under the optimum condition,the content of total polyphenols was 21.402 mg·g-1 and higher than that of the any orthogonal experiments.The antioxidative activity showed that the radical scavenging activity of persimmon pomace extract was up to 95.4% at 0.24 mg·mL-1,and DPPH· scavenging abilities of polyphenols extracts from persimmon pomace and Vc had no difference.These findings showed that persimmon pomace extract have strong antioxidant activity.