藜麦叶片多酚最佳提取工艺及其抗氧化性研究

Optimum Extraction of Quinoa Leaf Polyphenols and Its Antioxidant Activity

以藜麦叶为原料,研究藜麦叶片多酚的最佳提取工艺及体外抗氧化活性。在单因素试验的基础上,选取乙醇浓度、料液比、提取时间进行三因素三水平的Box-Behnken中心组合研究,并运用Design Expect8.0软件进行分析,通过响应面分析法对提取条件进行了优化,并对藜麦叶片多酚类物质的DPPH·和·OH清除能力进行分析。结果表明,藜麦叶片多酚的最佳提取条件为:乙醇体积分数83%,物料比1:20,80℃水浴条件下浸提1.12 h;藜麦叶片多酚类物质具有很强的清除DPPH·和·OH清除能力,其IC_(50)分别为1.876μg/mL和6.520μg/mL;同时发现藜麦叶片多酚的含量存在明显的品种间差异,其中品种Temuco的多酚含量最高,达到0.675g/100 g。

The optimum extraction conditions of polyphenols from quinoa leaves and their antioxidant activities in vitro were studied, using quinoa leaves as experimental material. On the basis of single factor test, the alcohol con- centration, solid - liquid ratio and extraction time were selected for the three - factor, three - level Box - Behnken experimental design. Design Expect 8.0 software was employed to analyze the test data and the response surface method was applied to optimize the extraction conditions. Additionally, the scavenging effects of polyphenols in quinoa leaves on free radicals such as DPPH · and · OH were subsequently analyzed. The results indicated that the obtained optimum extraction conditions were extracting reagent 83% ethanol, ratio of quinoa leaf powder to ethanol 1： 20, and extraction time 1.12 h in water- bath 80℃. Moreover, the polyphenols extracted from quinoa leaves exhibited a strong scavenging effect on DPPH · and · OH free radicals, and its IC50 （half inhibitory concentration） was respectively up to 1. 876μg/mL and 6. 520 μg/mL. Meanwhile, great variation in polyphenol content has been found in quinoa leaves among different varieties, of which variety ＇ Temueo＇ had the highest polyphenlo content, reaching 0. 675 g/100 g.