Department of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland.
Eur J Nutr. 2011 Dec;50(8):681-8. doi: 10.1007/s00394-011-0179-2. Epub 2011 Mar 1.
Antioxidant properties of the water extracts of the commercial bagged fruit and flavoured black teas were evaluated and compared with typical black teas of C. sinensis.
Folin-Ciocalteu (FC) assay, cupric ion reducing antioxidant capacity (CUPRAC) and DPPH radical method were used for these purposes. The content of selected flavonoids and phenolic acids was also determined by high-performance liquid chromatography with tandem mass spectrometry in the negative electrospray ionization mode.
Flavoured black teas contain significantly higher level of catechins, quercetin, and rutin, while the content of chlorogenic and caffeic acids as well as naringin and hesperidin was higher in fruit teas. Supplementation with these flavonoids could reduce blood glucose. In FC and DPPH assays, the antioxidant properties of studied tea infusion increases in the order: fruit tea < flavoured black tea > premium black tea, while in CUPRAC method, some aromatized teas exhibit the highest antioxidant properties. Tea infusions with nice smell of fruits would also support the human diet with some source of antioxidants.
评估并比较市售袋装水果茶和调味黑茶的水提取物的抗氧化性能与典型的中国红茶。
采用福林-考尔法（FC）、铜离子还原抗氧化能力（CUPRAC）和 DPPH 自由基法进行评估。还采用高效液相色谱-串联质谱法在负离子电喷雾电离模式下测定了选定的类黄酮和酚酸的含量。
调味黑茶含有明显更高水平的儿茶素、槲皮素和芦丁，而水果茶中绿原酸和咖啡酸以及柚皮苷和橙皮苷的含量更高。这些类黄酮的补充可以降低血糖。在 FC 和 DPPH 测定中，研究茶浸液的抗氧化性能按以下顺序增加：水果茶<调味黑茶<优质红茶，而在 CUPRAC 方法中，一些调味茶显示出最高的抗氧化性能。具有水果香味的茶也可以为人类饮食提供一些抗氧化剂来源。
