茶多酚树脂吸附层析法脱咖啡因的性能研究

研究发现不同性质的吸附树脂对茶多酚提取液中的各组分具有明显不同的吸附选择性，极性RS-1树脂对茶叶水提液具有明显脱色除杂效果；具有较高比表面积的弱极性吸附树脂RX-2对咖啡因具有较高的吸附容量和吸附选择性，动态吸附时发生层析分离，是一种较为理想的咖啡因脱除剂。经两级树脂纯化，茶叶水提液中EGCG、ECG的含量可由49.78%、11.56%提高至74.72%、17.45%，收率分别约为78.31%、83.46%，处理后咖啡因含量可降至0.2%以下。

Removal of Caffeine from Green Tea Extract by Macroporous Resin Adsorption

Adsorption and desorption capacities of various macroporous resins to polyphenols (EGCG, ECG) and caffeine in green tea extract were examined in an effort to remove caffeine from it. Results showed that RS-1 resin exhibited the best decoloration effect, and RX-2 resin exhibited strong selective adsorption capacity to caffeine, thereby providing an effective approach for removing caffeine from green tea extract. After the two-step resin separation, the relative contents of EGCG and ECG could reach 74.72% and 17.45% from 49.78% and 11.56%, with the yields of about 78.31% and 83.46%, respectively, and the caffeine content could be reduced to about 0.2%.