树莓叶茶和嫩尖茶抗氧化活性成分研究

目的 研究树莓叶茶和嫩尖茶的抗氧化活性成分。方法 对树莓叶茶和嫩尖茶的鞣花酸、黄酮和多酚含量进行了测定, 并与绿茶炒青进行了比较, 在此基础上考察了不同种类茶叶对DPPH和ABTS自由基的清除能力。结果 树莓叶茶和嫩尖茶的鞣花酸含量较为丰富, 最高达26.75 mg/g, 是特级炒青6.8倍, 黄酮含量也较绿茶炒青高, 达18~22 mg/g; 树莓嫩尖茶的多酚含量同炒青接近, 均超过180 mg/g, 两者的抗氧化活性均较强, 而树莓叶茶的总多酚含量较低, 仅为绿茶和树莓嫩尖茶36%~39%, 抗氧化活性较弱。相关性分析发现茶叶样品的抗氧化活性与多酚含量呈极显著正相关。结论 树莓叶茶抗氧化性较弱, 而嫩尖茶具有较强的抗氧化活性, 可以加以推广。

Analysis on the antioxidant components of raspberry leaf and tender tip tea

Objective To study the antioxidant components of raspberry leaf tea and tender tip tea. Methods The ellagic acid, flavonoid and polyphenol contents of raspberry leaf and tender tip tea were estimated and compared with a green tea chaoqing. Moreover DPPH and ABTS free radical scavenging abilities of the tea samples were investigated. Results The ellagic acid content of raspberry lea and tender tip tea were up to 26.75 mg/g, which was 6.8 times of the green tea, and the flavonoid contents ranged from 18 to 22 mg/g, which were also higher than green tea. The polyphenol content of raspberry tender tip tea was corresponding to the green tea, which were both up to 180 mg/g. The raspberry leaf tea had lower total polyphenol content and weak antioxidant activity, it was just 36%?39% of green tea and raspberry tender tip tea. The results of correlation analysis indicated a significant positive correlation between antioxidant activity and polyphenol content. Conclusion Raspberry leaf tea has weak antioxidant activity, while tender tip tea has strong antioxidant activity, which can be popularized.