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用普洱茶、绿茶、红茶、乌龙茶四种茶汤 ,分别加入不同浓度的Cu2 +溶液中测定铜的活性。结果显示 :不同茶类络合力明显不同 ,绿茶〉普洱茶〉红茶〉乌龙茶 ,这种效应与茶叶加工工艺及栽培措施有关 ,多酚类化含物是最重要的产生络合的物质 ,胺化合物能有效地络含 1 0 %～ 30 %的铜。因发酵工艺不同 ,铜溶液PH值下降变化不一样 ,PH值下降顺序为绿茶〉乌龙茶〉红茶〉普洱茶。 4种茶的络合效应随时间增加而降低 ,可能是Cu2 +能使茶叶中儿茶素氧化反应加快 ,而降低茶汤的络合效应的
With Pu’er tea, green tea, black tea, oolong tea four kinds of tea were added to different concentrations of Cu2 + solution in the determination of copper activity. The results showed that: the complexing ability of different kinds of tea was obviously different, and green tea> Pu’er tea> black tea> oolong tea. The effect was related to the tea processing technology and cultivation measures. The polyphenols content was the most important complexing substance, The compound can effectively contain 10% ~ 30% copper. Due to the different fermentation process, the PH value of copper solution changes not the same, the order of decreasing PH value is green tea> oolong tea> black tea> pu-erh tea. The complexing effect of four kinds of tea decreased with time, probably Cu2 + can accelerate the oxidation reaction of catechins in tea, and reduce the complexation effect of tea