提高茶树鲜叶儿茶素含量的不同光质萎凋工艺研究

为加工出富含儿茶素类含量的茶叶,本试验探索了提高茶树鲜叶儿茶素类含量的不同光质萎凋工艺。试验以茶树新品系HK-2和HK-3为材料,采用白光（CK）、红光、黄光、蓝光、紫光光质进行萎凋,于照射0、2、4、6、8、12、24 h时取样,利用UPLC（超高效液相色谱仪）进行简单儿茶素[表没食子儿茶素（EGC）、表儿茶素（EC）、儿茶素（C）]和酯型儿茶素[表没食子儿茶素没食子酸酯（EGCG）、表儿茶素没食子酸酯（ECG）、没食子酸儿茶素没食子酸酯（GCG）、儿茶素没食子酸酯（CG）]含量的测量。结果表明,与白光组CK相比,HK-2品系茶树鲜叶采用4 h的蓝光萎凋工艺,简单儿茶素含量显著增加了21.64%,6 h的蓝光萎凋工艺EGCG、酯型儿茶素和儿茶素总量的含量分别显著增加了23.31%、38.56%和35.78%;HK-3品系茶树鲜叶采用12 h的蓝光萎凋工艺EGCG含量显著增加了33.18%,6 h的蓝光萎凋工艺简单儿茶素、酯型儿茶素和儿茶素总量分别显著增加了75.49%、35.83%和38.51%。以7种儿茶素组分的相对含量进行主成分分析和聚类分析结果表明：不同光质萎凋能调控茶树鲜叶在萎凋过程中儿茶素含量的变化,其中蓝光萎凋6 h处理是提高茶树鲜叶儿茶素类含量的最佳工艺。

Withering Technology of Different Light Quality to Increase Catechin Content in Fresh Tea Leaves

In order to produce catechins-rich tea, this study explored different light quality wilting processes to increase the catechins content in fresh tea leaves. Leaves from new tea tree strains HK-2 and HK-3 were treated with white light (CK), red light, yellow light, blue light, and purple light for withering, and UPLC (Ultra Performance Liquid Chromatography) was used to detect the content of simple catechins [epigallocatechin (EGC), epicatechin (EC), catechin (C)] and ester catechins[epigallocatechin gallate (EGCG), epicatechin gallate (ECG), catechin gallate (GCG), catechin gallate (CG)] in samples lit for 0, 2, 4, 6, 8, 12, 24 h. Compared with CK, 4 h blue light withering process could significantly increase the content of non-ester catechin in the fresh leaves of HK-2 by 21.64% and the contents of EGCG, ester catechin and total catechin were significantly increased by 23.31%, 38.56% and 35.78% respectively after 6 h treatments. It was worth noting that the EGCG content of HK-3 was significantly increased by 33.18% after 12 h blue light withering treatment, and the total contents of non-ester catechins, ester catechins and catechins were significantly increased by 75.49%, 35.83% and 38.51% respectively after 6 h treatment. Combined with principal component analysis and cluster analysis, the results showed that different light quality withering could regulate the changes of catechins content in fresh leaves of tea plants during the withering process, and blue light withering for 6 h was the optimum process to increase the catechins content in fresh tea leaves.