黄光萎凋对红茶品质的影响

Effects of yellow light irradiation during withering of tea leaves on the qualities of black tea

在萎凋过程利用黄光照射茶叶,分析黄光处理对红茶品质的影响。结果表明,黄光照射处理对红茶的外形和汤色品质影响较小,香气和滋味品质显著提高,香气的甜度以及滋味的鲜爽度和甜度显著提高。理化分析结果表明,除多酚和可溶性糖外,黄光处理对红茶的儿茶素、茶黄素、氨基酸和香气成分的影响较显著。红茶经过黄光处理后,其儿茶素总量提高21.6%、茶黄素含量提高17.6%、氨基酸含量提高6.8%,香气总量增加21.7%,而醛酮类和烷烯烃类变化较小。

Yellow light was used to irradiate plucked leaves during its withering. The withered leav- es were subjected to cutting and drying. The qualities of black tea were analyzed. The results showed that yellow light significantly improved the aroma and taste. The sweet flavor and fresh and mellow taste of black tea was less affected. The concentrates of catchins, theaflavins,amino acids and aroma components except polyphenols and soluble sugars were significantly increased as well. After irradiation of yellow light, the total content of catechins in black tea increased by 21.6 %, among which EGCG, ECG, GC and EC were increased remarkably with no significant difference in EGC and C. The total content of theafla- vins in black tea withered with yellow light had an increase of 17.6%. But each theaflavin showed differ- ent variation with a significant increment in TF1 and TF2A, but there was no significant difference in TF3 and TF2B. It is indicated that the amimo acids of black tea withered with yellow light increased by 6.8% with a significant increment in aspartic acid, glutamic acid, yaline,isoleucine and theanine. The re- sult of GC/MS analysis showed that there was 21.7% increase of total content of aroma components. The predominant types of acids and anhydrides, alcohols, esters and aromatic compounds increased by 58. 5%,41. 2%, 25. 4% and 18. 6%, respectively. Amides decreased by 127. 3%. It is indicated that yellow irradiation during tea leaves withering can improve the qualities of black tea.