8种市售茶类饮料抗氧化活性及总酚含量的研究

Antioxidant activities and total phenolic contents of eight kinds of commercial tea drinks

采用FRAP、DPPH和ABTS 3种方法测定了8种市售茶类饮料的抗氧化活性并用Folin-Ciocalteu法测定其总酚含量。结果表明:8种茶类饮料在抗氧化活性和总酚含量方面是很好的抗氧化剂来源。在FRAP和ABTS试验中,绿茶饮料的抗氧化活性最强,TEAC平均值分别为5 878.66、7 266.99μmol/L,红茶饮料的抗氧化活性最弱,TEAC平均值分别为2 748.40、3 478.71μmol/L;在DPPH试验中,红茶饮料的抗氧化活性最强,VCEAC平均值为20 406.10μmol/L,绿茶饮料的抗氧化活性最弱,VCEAC平均值为17 481.76μmol/L;总酚含量结果表明,绿茶饮料450.76μg GAE/mL>乌龙茶饮料357.91μg GAE/mL>红茶饮料247.83μg GAE/mL。此外,试验结果显示,茶饮料的总酚含量与其抗氧化活性并不一定存在量效关系。

FRAP, DPPH and ABTS methods were used to determine the antioxidant activities of eight kinds of commercial tea drinks, and Folin-Ciocalteu method was used to determine their total phenolic contents. Results indicated that eight kinds of tea drinks were significant sources of antioxidants in terms of their antioxidant activities and total phenolic contents. In FRAP and ABTS assays, green tea drinks exhibited the highest antioxidant activity with the mean values of TEAC 5 878.66 and 7 266.99 μmol/L respectively, black tea drinks had the lowest antioxidant activity with the mean values of TEAC 2 748.40 and 3 478.71 μmol/L respectively; in DPPH assay, black tea drinks exhibited the highest antioxidant activity with the mean value of VCEAC 20 406.10 μmol/L, and green tea drink had the lowest antioxidant activity with the mean value of VCEAC 17 481.76 μmol/L; total phenolic contents study showed： green tea drinks 450.76μg GAE/mL 〉 oolong tea drinks 357.91 μg GAE/mL 〉 black tea drinks 247.83μg GAE/mL. In addition, it was confirmed that total phenolic contents of tea drinks was not always proportional to their antioxidant activities.