摊放环境对名优绿茶鲜叶茶多酚及儿茶素组成的影响

以单芽或一芽一叶茶鲜叶为原料,设置连续(78%～61%)摊放水分处理和不同环境条件摊放试验处理,分别进行液氮固样和冷冻干燥,测定茶多酚和儿茶素组分含量,研究摊放过程和摊放环境对茶多酚和儿茶素组成变化的影响。结果表明,摊放过程中茶多酚和儿茶素总量呈现前期下降后期有所上升的趋势,酯型儿茶素总量逐渐下降,EGC、EGCG,EC及GCG等儿茶素组分呈逐渐下降趋势,而C,ECG等组分呈逐渐上升趋势,鲜叶和摊放叶中检测不到没食子酸儿茶素(GC)。在摊放叶含水量控制在70%左右的前提下,环境温度与湿度对摊放过程中的化学成分变化有明显的影响,低湿环境下(60%)的茶多酚和儿茶素总量呈下降趋势,高湿环境下(90%)的茶多酚和儿茶素总量呈上升趋势,而中湿(75%)对茶多酚和儿茶素总量的影响与环境温度关系密切。

Effects of Spreading Environment on Tea Polyphenols and Catechin Components in Tea fresh Leaves of High Quality Green Tea

Using one bud or one leaf and one bud as material,fresh tea leaves were spread continuously(78%~61%) and spread under different environment conditions,then fixed with liquid nitrogen and freeze-dried,respectively.The effects of spread process and spread environments on the change of tea polyphenols and catechin components were investigated.The results showed that the contents of tea polyphenols and total catechins decreased at beginning and then increased during spreading,total esters type catechins decreased gradually,epigallocatechin gallate(EGCG),gallocatechin gallate(GCG) and epicatechin gallate(ECG) decreased in amount during spreading,whilst epicatechin(EC) and epigallocatechin(EGC) increased,but gallocatechin(GC) could not be checked out in fresh tea leaves and spread tea leaves.With the precondition of that the moisture of spread leaves was controlled at 70%,there was obvious effect of environment temperature and humidity on the change of chemical components during spreading.Contents of tea polyphenols and total catechins decreased in low relative humidity(60%),but increased in high relative humidity(90%).The effects of middle relative humidity(75%) on tea polyphenols and total catechins was correlative with environment temperature.