实验教学中超声波辅助乙醇法提取茶叶咖啡因研究

Research on Ultrasonic Assisted with Ethanol to Extract Caffeine from Green tea for University Teaching Experiment

研究了超声波辅助乙醇提取法对茶叶中咖啡因提取的最佳方案.通过单因素和正交设计实验,绿茶在95%溶剂中经超声波预处理5min后,得到咖啡因提取最佳条件为20%超声功率比,70℃浸提温度,95%乙醇浓度,100mL溶剂用量和60min浸提时间,咖啡因的提取量最高每6g茶叶为99mg,提取率为82.5%.该法操作简单,无环境污染,提出产物纯度高,提取率高.所得最佳参数可应用于教学实验和工业化生产中.

In this paper,the best scheme on caffeine extraction from green tea has been investigated by a method of combining ultrasonic assisted with ethanol extraction.The best extraction parameters have been optimized by using single-factor and orthogonal tests.The results indicate that after ultrasonic pretreatment of green tea in 95%alcohol solution for 5 min,the amount of caffeine extraction is highest in which 99 mg caffeine per 6 g green tea can be extracted and the extraction rate reaches 82.5%under the best test condition that is 20%ultrasonic power ratio,100mL 95%alcohol and 60 min extraction at 70℃.The extraction method exhibits many advantages such as simple,no environmental pollution,a product of high purity and high extraction efficiency.The gained optimal parameters can be applied in both teaching experiment and industrial production.