杏仁皮单宁提取工艺优化及其DPPH自由基清除活性

以杏仁皮单宁得率为指标,考察了料液比、提取时间、提取温度、乙醇体积分数四个因素对杏仁皮单宁提取效果的影响。在单因素基础上,采用响应面法优化杏仁皮单宁提取工艺,并对最佳工艺下所得杏仁皮单宁的DPPH自由基清除活性进行测试。结果表明:所建立的杏仁皮单宁提取工艺模型极显著,其最优实验条件是料液比1:22 (g/mL)、提取时间89 min、提取温度70 ℃、乙醇体积分数50%,在此条件下杏仁皮单宁得率为2.13%。杏仁皮单宁浓度为250 μg/mL时对DPPH自由基的清除率达到98.65%,表明杏仁皮单宁具有较强的抗氧化活性。

Optimization of Extraction Process of Tannins from Almond Skin and Its DPPH Radical Scavenging Activity

The yield of almond skin tannins was served as indicator,and the four effects of factors on the extraction efficiency of almond skin tannins were investigated,such as solid to liquid ratio,extraction time,extraction temperature and volume fraction of ethanol. On the basis of single factor,response surface methodology was used to optimize the extraction process of almond skin tannins,and the DPPH radical scavenging activity of almond skin tannins was tested under the optimal process. The results showed that the extraction process model of almond skin tannins was highly significant. The optimum conditions were as follows:the ratio of solid to liquid was 1:22 (g/mL),the extraction time was 89 min,the extraction temperature was 70 ℃,and the volume fraction of ethanol was 50%. Under these conditions,the yield of almond skin tannins was 2.13%. When the concentration of almond skin tannins was 250 μg/mL,the DPPH radical scavenging rate reached 98.65%,which suggested that almond skin tannins had strong antioxidant activity.