绿茶表没食子儿茶素没食子酸酯浸提工艺研究

Study on Extraction Technology of EGCG from the Green Tea

目的:研究绿茶中表没食子儿茶素没食子酸酯(EGCG)的提取工艺,并对不同产地低档茶叶的茶多酚和EGCG的含量进行比较。方法:采用HPLC法测定EGCG含量,以EGCG提取率为考察指标,做单因素试验,再采用正交试验方法,对提取奈件进行优化。结果:影响绿茶中EGCG提取效果的主次因素为:乙醇用量>乙醇浓度>回流时间>提取温度。结论:最佳浸提条件为:固液比1:15,以40%乙醇在60℃浸提2次,每次30min,且新茶中EGCG提取率相对较高。

Objective： To study the extraction technology of EGCG from the green tea and to compare the contents of EGCG and tea- polyphenols in low grade green tea. Method： The EGCG extraction rate was determined by HPLC, EGCE was used as the single factor to find the optimum extractive conditions and than used the orthogonal design. Result： The factors which influence extraction rate was as follows ： solid and liquid rtio 〉 amount of alcohol 〉 extration time 〉 temperature, where A, B, C and D stands for the the dosage of ethanol, concentration of ethanol, extract time and temperature of leaching, respectively. Conclusion： The optimum technology of extraction was as follows： 40% ethanol, fifteen - fold leachant, 2 times extraction and 0. 5 hour each time at 60 ℃. The extraction rate of EGCG in fresh green tea is relative high.