Research of the chemical components and the antioxidant activities of Jinxuan green tea, oolong tea and black tea in summer

The chemical components and the antioxidant activities of Jinxuan green tea, oolong tea and black tea in summer, spring and autumn were determined in this article.The results showed that Jinxuan green tea in summer showed the strongest antioxidant ability, followed by spring tea and autumn tea. The content of tea polyphenols, catechins and esters- catechin of Jinxuan green tea in summer were also the highest among all the green tea in different seasons.The antioxidant ability of Jinxuan oolong tea in summer was strongest in different seasons and was very closed to that of Jinxuan green tea in spring, next only to Jinxuan green tea in summer.although Jinxuan oolong tea in summer contained lower tea polyphenols, catechins and esters- catechin than oolong teas in other seasons, it contained the highest concentration of tea polysaccharide. There was no significant difference in the antioxidant activities of Jinxuan black tea in different seasons.For the different types of teas, Jinxuan green tea had the strongest antioxidant ability, followed by oolong tea and black tea.