Abstract:Polyphenols from the shell of sacha inchi with ethanol extraction were optimized in this work. The effects of the ethanol concentration，the material-liquid ratio，extraction temperature and the extraction time on the extraction yield of polyphenols were explored by single-factor and orthogonal test.The antioxidant of extract was studied in two different systems （hydroxyl radical and DPPH radical）and was comparable to tertbutylhydroquinone（TBHQ），vitamin C（VC）and butylated hydroxytoluene（BHT）.The results showed that the influences of four factors on the extraction results of polyphenol content in the shell of sacha inchi in order were extraction temperature > concentration of ethanol >the material -liquid ratio> extraction time. The optimal techniques for extracting polyphenol in the sacha inchi shell were as follows：water bath at 90 ℃，the extraction solvent of ethanol of 70%，the material-liquid ratio of 1 ∶55（g/mL），and extracting time for 2.0 h，and thus extraction yield was 4.79%. The polyphenols from the sacha inchi shell showed a stronger scavenging hydroxyl radical activity and more effective scavenging DPPH activity compared with TBHQ，VC and BHT. The IC50 achieved 5.86×102 μg/mL and 7.51 μg/mL，respectively.