四川乌龙茶做青程度对品质形成的影响

Effects of Tossing on Quality Formation of Sichuan Oolong Tea

采用川茶群体品种的春夏秋鲜叶原料,对乌龙茶加工关键环节做青工序分别设计摇青和摊青结合的3种组合实验,采用感官审评与成分测定相结合的手段,探讨做青方式对四川乌龙茶品质形成的影响效应。结果表明:采用摇青4次、摊青9h(1h+1.5h+2h+2h+1.5h+1h)制得乌龙茶品质较优,香味总评分为56.2~61.4分;儿茶素总量降低了1.51~9.08mg/g;茶黄素(theaflavins,TFs)、茶红素(thearubigns,TRs)、茶褐素(theabrownines,TBs)分别增加了0.026%~0.043%、0.39%~0.57%、0.55%~0.83%。春、夏、秋季都以摇青4次、摊青9 h(1h+1.5h+2h+2h+1.5h+1h)制成的乌龙茶,其中秋季品质较优,春季次之,夏季较差,其香味总评分分别为61.4、60.0、56.2分。提示,通过控制做青程度,调节半发酵水平,将有利于四川乌龙茶加工技术提高及产品品质的改善。

This study aimed to explore the effects of three combinations of tossing and spreading(totally called Zuoqing) on Sichuan oolong tea made from fresh leaves of Sichuan tea plant varieties harvested in Spring, Summer and Autumn by sensory evaluation and chemical composition analysis. The result showed that better tea quality was achieved by four tossing cycles combined with 9 h of spreading(1 h + 1.5 h + 2 h + 2 h + 1.5 h + 1 h), yielding total sensory scores in terms of aroma and taste ranging from 56.2 to 61.4. Besides, the total catechin content was reduced by 1.51–9.08 mg/g, while the relative contents of theaflavins(TFs), thearubigns(TRs) and theabrownines(TBs) were increased by 0.026%–0.043%, 0.39%–0.57% and 0.55%–0.83%, respectively. The oolong tea made from Autumn-harvested tea leaves using this combination of tossing and spreading scored highest in total sensory scores for taste and aroma, followed by that made from Spring-harvested tea leaves, and Summer-harvested tea leaves exhibited the lowest score, which were 61.4, 60.0 and 56.2, respectively. This study indicates that the semi-fermentation of tea leaves can be controlled by adjusting Zuoqing, providing a promising way of improving the quality of Sichuan oolong tea.