响应面法优化红巨苋多酚的提取工艺及抗氧化性

以红巨苋为材料,采用有机溶剂浸提法,在单因素试验的基础上,选取乙醇体积分数、料液比、浸提时间进行三因素三水平的Box-Benhnken中心组合试验,并通过响应面分析法对提取工艺参数进行优化;同时,对红巨苋叶片多酚物质的DPPH和OH自由基的清除能力进行分析。结果表明,红巨苋叶片多酚最佳提取工艺条件为:乙醇体积分数70%,料液比1∶51g/ml,浸提时间31min;三因素对提取率的影响大小依次为乙醇体积分数、料液比、浸提时间。在此条件下,红巨苋叶片多酚得率实际平均为13.92%,与理论预测值13.94%相近。红巨苋叶片多酚类物质对DPPH和OH自由基的清除率都在一个较高的水平,具有明显的抗氧化作用。

Extraction optimization of polyphenols from red giant amaranth by response surface methodology and its antioxidant activity

The optimum extraction conditions of polyphenols from red giant amaranth leaves using organic solvent extraction method by the response surface methodology were studied in the research.On the basis of single factor test,the ethanol concentration,solid-liquid ratio and the extraction time were selected for the three-factor,three-level Box-Behnken experimental design. The response surface methodology was used to determine the optimum extraction conditions of polyphenols in red giant amaranth leaves.Additionally,the scavenging effects of polyphenols in red giant amaranth leaves on free radicals such as DPPH·and·OH were analyzed.The results indicated that the optimum extraction conditions were as follows:ethanol concentration 70%,ratio of leaf powder to ethanol 1∶51 g/ml and extraction time 31 min.The sequence of factors which worked on the extraction rate of polyphenols was as follows:ethanol concentration、solid-liquid ratio、extraction time.On these conditions,the average yield of polyphenols was 13.92%,which was close to the theoretical prediction value of 13.94%.Moreover,the polyphenols extracted from the red giant amaranth possessed a strong scavenging effect on DPPH·and·OH free radicals,exhibiting obvious antioxidant activity.