水仙乌龙茶膨化前后滋味和香气成分分析

Analysis of the Taste and Aroma Components in Shuixian Oolong Tea Before and After Extruding

采用膨化工艺对水仙乌龙茶进行处理,分析膨化前后茶叶的香气和滋味成分的变化。结果表明:茶叶膨化后滋味成分中的水浸出物、灰分、咖啡碱与茶多酚的含量有所降低,而碳水化合物含量则有所提高。膨化后茶叶滋味成分的改变影响茶汤的滋味,咖啡碱和茶多酚的减少,使膨化后茶汤苦味和涩味变淡,而碳水化合物增加,使茶汤显得更加甘醇。茶叶膨化后,香型发生一定转变,原乌龙茶的特征成分吲哚、苯乙腈含量比例减少,橙花叔醇未检出,而热裂解产物吡嗪类、吡咯类化合物增加明显,使膨化茶叶呈现出类咖啡焦香味。

In this paper,the Shuixian Oolong tea was processed by extruding technique.The aroma and taste components in the Shuixian Oolong tea before and after extruding processing were analyzed.The results were summarized as follows： compared with the original tea,the contents of taste components such as the water soluble substance,ash and tea polyphenol in extruded tea were reduced,while the content of carbohydrate increased.The flavor of tea was affected by the changes of the components.The decrease of caffeine and tea polyphenol reduced a little of bitter and astringent taste in the extruded tea.While the increase of carbohydrates gave the extruded tea taste mellower.After extruding,the aroma feature had some changes.The characteristic ingredients of Oolong tea such as indole,benzylcyanide were reduced.And nerolidol was undetected.The pyrolysates such as pyrazines,pyrroles increased significantly because of the heat.This brought a coffee flavor to the extruded tea.Extruding processing provided a new way for the use of Shuixian Oolong tea.