祁门红茶多酚提取工艺优化及其组成鉴定

Optimization of extraction technology of keemun black tea polyphenols and its composition identification

以祁门红茶为原料,优化了红茶多酚提取的工艺条件。通过单因素实验考察乙醇体积分数、提取温度、提取时间、料液比、p H对红茶多酚提取率的影响,并进一步采用正交实验优化提取工艺,得到最佳工艺为:乙醇体积分数60%,提取温度70℃,提取时间2.5 h,料液比1∶50(g/m L),p H4。在此工艺下,提取两次后红茶多酚提取率为(214.23±6.29)mg/g。采用UPLC-DAD鉴定祁门红茶的多酚组成,结果表明,祁门红茶多酚的主要成分为没食子酸、没食子儿茶素、表儿茶素、表没食子儿茶素没食子酸酯、表儿茶素没食子酸酯、儿茶素没食子酸酯、茶黄素、茶黄素-3-没食子酸酯、茶黄素-3′-没食子酸酯和茶黄素双没食子酸酯。

The extraction technology of black tea polyphenols was optimized using keemun black tea as material.The effect of ethanol concentration,extraction temperature,extraction time,solid-liquid ratio,p H on extraction yield was investigated by single-factor experiment and the extraction technology was further optimized by orthogonal experiment. The optimum extraction parameters were as follows ：ethanol concentration 60%,extraction temperature 70 ℃,extraction time 2.5 h,and solid-liquid ratio 1∶50（g/m L）. The extraction yield was（214.23±6.29） mg/g after the second extraction. In addition,UPLC-DAD was applied to identify keemun black tea polyphenols. Results showed that the main components of keemun black tea polyphenols were gallic acid,（-）-Gallocatechin（GC）,（-）-Epicatechin（EC）,（-）-Catechin gallate（CG）,（-）-Epicatechin gallate（ECG）,（-）-Epigallocatechin gallate（EGCG）,Theaflavin（TF1）,Theaflavin 3-gallate（TF3G）,Theaflavin 3 ＇-gallate（TF3′G） and Theaflavin 3,3＇-digallate（TF33′G）.