绿茶萃取物溶出变化研究

研究绿茶在50、60、70、80℃水中不同时段萃取时萃出液中茶多酚(EG、EGC、ECG、GGEG)、氨基酸、果胶等的变化。结果显示,游离型儿茶素在冷水中比较容易溶出,3萃时有80%～90%溶出;酯型儿茶素的溶出较慢,3萃时只有50%左右溶出;咖啡因的溶出特性与游离型儿茶素相类似;氨基酸在1萃溶出量较多,从1萃到3萃前,依次下降,除精氨酸外,其他氨基酸在2萃时溶出率达70%～80%,3萃时溶出率为90%～100%,精氨酸在2萃时溶出率为50%,3萃溶出率为70%;钙、镁、磷酸类在1～3萃取中溶出量依次降低;1萃时水溶及盐溶性果胶的萃取率较高。以上参数为茶饮料的工业化生产及品质保证提供参考。

Study on extraction yield of green tea

The changes of polyphenol(EG、EGC、ECG、GGEG),amino acid,pectin etc.in green tea extraction at the temperature of 50、60、70、80℃were studied.Results showed extraction of free catechin was easy in cool water,extraction rate was 80%～90%during 3 times extract,estered catechin was difficult,the rate was only 50% during 3 times extract.The extract rate of caffeine was the same as estered catechin;the extract rate of amino acid was higher in 1 time extraction.the rate descends with 1～3 time extract.Beside of Arg,the extract rate of other amino acid attained 70%～80% in 2 time extract.90%～100% in 3 time.The rate of Arg was 50% in 2 time extract.70% in 3 time.The rate of calcium/magnesium/phosphorus gradually descended with 1～3 time extract.The extract rate of hydrate and salted pectin was higher in 1 time extract.The above parameters were the reference in tea beverage processing and quality asseurance.