烘焙工艺对丹桂乌龙茶感官品质及生化成分的影响

以丹桂乌龙茶(闽南)毛茶为研究对象,采用5因素4水平正交设计,探讨丹桂乌龙茶精制过程中变温烘焙工艺对其品质的影响。结果表明,A4B1C4D2E3及A3B2C4D3E1处理茶品质最佳,具有清香稍带甜香、滋味醇爽、汤色金黄明亮或花香显、滋味浓醇、汤色金黄的品质特点。丹桂乌龙茶变温烘焙包括3个阶段,即高温去杂、低温慢焙、高温提香阶段,较佳参数为120℃、20 min,90℃、130 min,120℃、30 min或110℃、30 min,90℃、140 min,130℃、10min。烘焙对丹桂乌龙茶生化成分的影响结果表明,烘焙可显著增加其水浸出物及咖啡碱含量。极差分析表明,影响因子的主次顺序为:DEABC;第三烘焙阶段中的烘焙温度、时间为烘焙的主效因子。

Effect of Baking on Quality and Biochemical Composition of Dangui Oolong Tea

4 levels and 5 factors were used in the orthogonal test to investigate the effect of baking temperature and time on quality of Dangui Oolong tea from southern Fujian.The results showed that treatments of A4 B1 C4 D2 E3 and A3 B2 C4 D3 E1 produced teas of the highest quality.The brewed tea was golden and bright soup,lightly scented with slight sweetness in aroma,or with floral aroma,and mellow in taste.The tea baking was carried out in 3 stages:the first done with a higher temperature to eliminate off-flavors,the second with a lower temperature and longer time to generate flavoring components in teas,and the last with a higher temperature to accentuate the aroma.The optimal temperature and time for the 3 baking stages were found to be 120℃ for 20 min,90℃ for 130 min,and 120℃ for 30 min.An alternative process was called for 110℃ for 30 min,90℃ for 140 min,and 130℃ for 10 min.The biochemical composition in tea was also altered during baking.The contents of caffeine and water extracts were significantly increased.The orthogonal experiment indicated that, as far as baking was concerned,the third stage affected the tea quality most significantly.