茶叶中茶多酚的提取纯化及咖啡碱和茶多糖的联产制备

Extraction and purification of tea polyphenols and simultaneous preparation of caffeine and tea polysaccharides from tea

设计了一条高效提取纯化茶多酚，并联产制备咖啡碱和茶多糖的综合提取工艺。首先通过单因素实验和正交实验优化，确定了弱酸性水溶液提取茶多酚的最佳组合方案：在60℃的条件下用30倍pH5～6的蒸馏水反复提取4次，每次浸提时间为50min，茶多酚提取率达到95．04％，较普通水提法提高了30．58％，经纯化后纯度达到85．56％；以分步萃取方法从茶多酚提取液中分离咖啡碱（1．36mg·g-1，纯度93．28％）、茶多糖（14．46mg·g-1，总糖含量大于65％），实现茶叶中多种有效成分的综合利用。

In order to extract and purify tea polyphenols,as well as to obtain caffeine and tea polysaccharides simultaneously ,an effectively comprehensive extraction process was developed in this study. Firstly,the optimal extraction conditions for tea polyphenols were investigated by single-factor and orthogonal tests. The extraction yield （95.04%） and purity（85.56%） of tea polyphenols,increased 30.58% comparing with general water extraction,were achieved at the following optimal extraction conditions ：extraction temperature 60℃ ,solid-to- liquid ratio 1：30, pH5N6, extraction time 50min, extracting 4 times. Moreover, caffeine （ 1.36mg .g-1, purity 93.28%） and tea polysaccharides （14.46mg. g-1, contents of total sugar above 65%） were also isolated from extracts solution of tea by fractional extracting.