改性蒙脱石粉脱除绿茶提取液中咖啡因的工艺优化

Process Opitimization on Removing Caffeine from Green Tea Extract by Modified Montmorillonite

首先对蒙脱石粉进行了改性,得到改性蒙脱石粉;其次,以咖啡因的脱除率、茶多酚的损失率和茶多酚与咖啡因的相对分离度作为评价指标,研究了温度、时间、用量和pH 4个工艺参数对改性蒙脱石粉脱除绿茶提取液中咖啡因的影响。结果表明,4个工艺参数的较适宜值分别为改性蒙脱石粉用量4%、吸附时间2 h、吸附温度45℃和绿茶提取液p H2.5;在较适宜条件下,咖啡因的脱除率为89.39%,咖啡因/EGCG的相对分离度为7.87,为脱咖啡因绿茶提取液的研究提供了依据。

In this paper,the montmorillonite powder was first modified,and the modified montmorillonite powder was obtained.The removal rate of caffeine,the loss rate of tea polyphenols and the relative resolution of tea polyphenols and caffeine were used as evaluation indexes.The effects of four technological parameters including temperature,time,dosage and pH on the removal of caffeine from green tea extract by modified montmorillonite powder were investigated.The results showed that the optimum values of the four process parameters were that:the dosage of modified montmorillonite powder was 4%,the adsorption time was 2 h,the adsorption temperature was 45℃and the pH of green tea extract was 2.5.Under more favorable conditions,the caffeine removal rate was 89.39%,and relative resolution of caffeine and epigallocatechin gallate(EGCG)was 7.87.This experiment provides a basis for the study of decaffeinated green tea extract in the future.