核桃青皮甲醇提取物的抗氧化活性研究

Antioxidant Activity of Methanol Extract from Walnut Green Husks

为比较不同甲醇浓度提取对核桃青皮多酚的抗氧化活性差异,该研究以核桃青皮为原料,采用不同甲醇浓度进行提取,测定多酚含量,羟基自由基、超氧阴离子自由基和DPPH自由基清除率及还原力等抗氧化活性指标,比较不同甲醇提取液抗氧化活性间的差异。结果表明:所有青皮提取液均具有一定的抗氧化活性,以20%甲醇为提取剂提取的多酚含量最高,80%甲醇提取的多酚含量最低。利用抗氧化活性为评价指标,测得20%甲醇提取液对DPPH自由基、羟基自由基和超氧阴离子自由基清除率最高,分别为96.18%、61.18%和54.06%,还原力以0%甲醇提取剂的效果最佳为(0.692)。

To compare the differences in the antioxidant activity of polyphenols from walnut green husks under different methanol concentrations.In this paper,walnut green husks were used as the raw material,and extraction was conducted with different concentrations of methanol.Antioxidant activity indicators such as polyphenol content and hydroxyl OH,superoxide anion O;and DPPH(2,2-diphenyl-1-picrylhydrazyl)free radicals scavenging ability and reducing power were determined.Differences in the antioxidant activity of extracts under different methanol concentrations were compared.The results showed that all extracts of walnut green husks had certain antioxidant activity.The highest and lowest polyphenol content was obtained with 20% methanol and 80% methanol as extraction agent,respectively.With polyphenol content as the evaluation index of antioxidant activity,it was measured that the extract with 20% methanol had the strongest scavenging activity of DPPH,OH and O;free radicals,which were 96.18%,61.18% and 54.06%,respectively.The optimal reducing power(0.692)was obtained under 0% methanol extraction.