茶多酚水溶液浸提法生产低咖啡碱茶叶的研究

首次采用茶多酚水溶液浸提法脱除鲜茶叶与干茶叶中的咖啡碱,并保留其中的主要功能性成分茶多酚。鲜茶叶最佳浸提条件为:温度100℃,料液比1:10(g/mL),茶多酚水溶液质量体积分数5%,时间5min。此条件下咖啡碱脱除率达80.61%,比传统热水浸提法提高31.25%,且茶多酚无损失。干茶叶最佳浸提条件为:温度100℃,料液比1:20(g/mL),茶多酚水溶液质量体积分数15%,时间7min。此条件下咖啡碱脱除率达81.61%,且处理后的茶叶中茶多酚含量提高90.02%。研究结果表明,针对鲜茶叶和干茶叶原料,茶多酚水溶液浸提法均能有效脱除其咖啡碱,并有效保留或提高茶叶中的茶多酚,比传统热水浸提法有明显优势,是一种生产低咖啡碱茶叶的新方法。

Study on preparation of low-caffeine tea by tea polyphenol solution treatment

A new production method of low-caffeine tea was obtained.Both fresh and dry tea leaves were lixiviated by tea polyphenol solution and the decaffeination effects was compared with traditional hot water lixiviation method.The perecntage of decaffeination reached 80.61% when fresh tea leaf was decaffeinated with a ratio of tea leaf to water of 1:10(g/mL) in 5%(g/mL) tea polyphenol solution at 100℃ for 5min,which was 31.25% higher than decaffeinated by hot water.Meanwhile there was no loss of tea polyphenol after the decaffeination.Similarly,the percentage of decaffeination reached to 81.61% when dry tea leaf was decaffeinated with a ratio of tea leaf to water of 1:20(g/mL) in 15%(g/mL) tea polyphenol solution at 100℃ for 7min,and the content of tea polyphenol increased by 90.02% which was much higher than in undecaffeinated dry tea leaf.It was considered that the tea polyphenol solution treatment was a effective method to decaffeinate and retain tea polyphenol for both fresh and dry tea leaves.