Antioxidant properties and color parameters of herbal teas in China

Abstract

The popularity of herbal tea is increasing in China because of its beneficial effect on human health, especially for antioxidant function. Color is one of the important organoleptic characteristics of tea. The aim of this study was to supply new information on the antioxidant properties and color parameters of herbal teas for researchers and the general public. The in vitro antioxidant properties and color parameters of 110 herbal teas were systematically investigated in comparison with eight green teas in China. The results showed that the antioxidant property values and color parameters of herbal teas were more variable than those of green teas. The antioxidant property values of most herbal teas were lower than those of green teas, except for a few herbal teas with high values, which could be analogous or superior to green teas. Rattan tea ‘Teng Cha' (Ampelopsis grossedentata (Hand.-Mazz.) W. T. Wang) and Chinese rose tea ‘Yue Ji Hua' (Rosa chinensis Jacq.) showed significantly higher property values than green teas. Among all the herbal teas, a highly significant correlation coefficient was found between antioxidant capacity and total phenolic content. No significant correlations were detected between the color parameters and the antioxidant properties. Principal component analysis and hierarchical cluster analysis showed that the properties of five herbal teas were similar to green teas, whereas Yue Ji Hua and Teng Cha were superior to green teas. The results suggested that the some commonly consumed herbal teas in China might be promising and economic dietary sources of natural antioxidants.