水在超临界CO2脱除绿茶中咖啡因的作用研究

采用不同的茶叶预处理方式，并在不同的萃取条件下，用超临界CO2对茶叶进行脱除咖啡因试验，以考察茶叶含水量与咖啡因萃取率的关系。指出了水对咖啡因萃取的3方面影响，即脱附茶叶基质上的咖啡因、使茶叶膨胀而改善咖啡因的传质状况及抑制咖啡因从水相进入超临界流体相。同时说明了此3者对萃取过程的影响机理。

Study on the effect of water to caffeine extraction from green tea by supercritical carbon dioxide

The relationship was studied on the water content and the extent of caffeine extraction in extracting caffeine from green tea by supercritical CO_2 under varying extraction conditions and different tea pretreatments. The effects of water to caffeine extraction were pointed out in three aspects, respectively, freeing caffeine from the tea matrix, improving the caffeine transfer condition by swelling the tea volume and prohibiting caffeine from transferring from water phase to SCF-CO_2 phase. It was also explained that the effect mechanism of these aspects to the extraction process.