遮荫对茶叶中儿茶素总量及构成的影响

采用不同遮荫度覆盖黄旦茶园,对茶样内儿茶素总量及酯型、非酯型儿茶素含量进行检测分析。结果显示：与CK比较,蒸青样和成茶样中儿茶素总量均随遮荫度增大而呈整体下降趋势,其质量分数分别下降了3.08%-10.61%和2.65%-21.52%;其中酯型儿茶素变幅,蒸青样为-1.63%-5.28%,小于成茶样的-19.96%-10.35%;而非酯型儿茶素的降幅,蒸青样为9.90%-24.18%,大于成茶样的2.90%-19.82%。蒸青样中酯型与非酯型儿茶素的质量分数总体虽随遮荫度增大而减少,但酯型儿茶素占总儿茶素的百分比却随之增大,增幅为4.32%-10.05%;而非酯型儿茶素占比却与之相反,下降了5.10%-15.17%;因而酯型与非酯型儿茶素含量的比值是随遮荫度增加而增大的。遮荫对茶叶内儿茶素总量及其构成的影响程度达到了或接近于种间差异水平。

The Effects of Shading on Total Content and Components of Catechins in Tea Plant leaves

In this study, Huang Dan was selected as experimental materials, using the technique of artificial cover shading of tea garden which could adjust the light, then steamed green tea and oolong tea samples were prepared for comparative analysis of the contents of total eatechins, ester and non-esterified catechins. The results showed cover shading had affects on the total content of catecbins both in steamed green tea and oolong tea samples. With the increase of shading degree, the total contents of catechins in both tea samples showed declining trend overall, the mass fraction change （compared with CK, similarly hereinafter） ranged respectively： steamed green tea samples, from 3.08% to 10.61%, and oolong tea samples, from 2.65% to 10. 61%; in both samples the mass fraction of ester catechins ranged respectively from - 1.63 % to 5.28 % and from - 19.96 % to 10.35 % ; the mass fraction of non-esterified catechins ranged respectively from 9.90% to 24.18% and from 2.90% to 19.82%. Although both ester and non-erterified catechins declined as the increasing of shading degree, but the ester catechin percentage of total catechin was increased, ranged from 4.32% to 10.05% ; on the contrary, the esterified catechin was declined from 5.10% to 15.17%. While, the ratio of ester and non-esterified catechins also showed bigger with the increasing of shading degrees. In conclusion, the study showed that the effects of shading treatment on total content and components of catechins could reach or be close to the levels of the difference among different tea plant varieties.