Study on Extraction Technology of Polyphenols from Late Harvest White Grape Pomace and Determination of Its Antioxidant Activity

In this study, late harvest white grape pomace was used as material to extract polyphenol. The extraction process of polyphenol from grape pomace was optimized via single-factor test, orthogonal test and variance analysis, and the antioxidant activities of the polyphenols were determined. The results showed that ethanol concentration and extraction temperature had a significant effect on the polyphenol extract. The optimal extraction conditions were as follows: 50% ethanol concentration, extraction temperature 80℃, extraction time 40min. Under the optimized conditions the yield of polyphenol was 3.39 mg/g. The determination result showed that the polyphenol had strong antioxidant activity.