绿茶910 EGCG的提取工艺

以绿茶910为原料,采用咖啡碱沉淀—溶剂萃取法对茶叶表没食子儿茶素没食子酸酯(EGCG)进行提取,运用二次回归正交旋转组合设计方法分析各影响因子对EGCG提取纯度的影响.结果表明,各因子对EGCG提取纯度影响程度的大小为:氯仿萃取次数>乙酸丙酯萃取次数>水浸提温度>咖啡碱浓度>己酸乙酯萃取次数.EGCG提取的最佳条件为:水浸提温度80℃,咖啡碱浓度30 mmol.L-1,氯仿萃取次数为5,己酸乙酯、乙酸丙酯萃取次数均为3.根据最佳条件提取EGCG,得到纯度为80.3%的EGCG产品.

Optimization of the extraction technology of EGCG from green tea

In order to prepare epigallocatechin-3-gallate(EGCG) from tea by caffeine precipitation and solvent partition,the experiment of technology optimization for EGCG extraction from tea was carried out with the design of the rotation-regression-orthogonal combination.The parameter models with the purity of EGCG as target functions were established.The optimization parameters for the extraction of EGCG from tea in caffeine precipitation and solvent partition system were as follows: water temperature,caffeine concentration,the number of partition with chloroform,with ethyl hexanoate,and with propyl acetate.Additionally,the mathematic model was well established to estimate the purity of EGCG within the investigated range.By the extraction parameters,the EGCG production system was obtained.The product was gained and then measured by high performance liquid chromatography(HPLC).The results indicated that the best EGCG extraction parameters were water temperature,80 ℃;caffeine concentration,30 mmol·L-1;the number of partition with chloroform,5;with ethyl hexanoate,3;and with propyl acetate,3.Under these extraction parameters,the product was obtained,finally its purity was more than 80.3%,as judged by HPLC.