漳平水仙茶加工过程中香气前体含量的变化

摘要

采用沸乙醇法提取漳平水仙茶中糖苷类香气前体物质，再经双相酶解法释放香气物质，经标准质谱图库检索、标准样品质谱图对照和保留时间比较等方法，鉴定出漳平水仙茶中主要含有青叶醇、芳樟醇、水杨酸甲酯、香叶醇、苯甲醇、苯乙醇等6种糖苷类香气前体。实验测定了整个加工过程中12个工序的茶样的糖苷类香气前体含量，结果表明，漳平水仙茶春茶和秋茶各加工工序茶样含有相同种类的糖苷类香气前体，但各组分的含量存在差异，秋茶中糖苷类香气前体的含量明显较春茶的高；晾青叶中糖苷类香气前体含量较鲜叶有显著增加，摇青工序使糖苷类香气前体含量发生变化，说明摇青叶在做青过程中存在着糖苷合成与酶解的动态平衡。%The glycosidic aroma precursors of Zhangping Shuixian tea were extracted by boiling ethanol, and the aroma substances, released from the precursors by biphase enzymolysis, was analyzed by GC-MS. The aroma substance was identified by the method of the standard mass library retrieval, the mass spectrogram of standard samples, and the retention time, 6 glycosidic aroma precursors were identified from Zhangping Shuixian tea: cis-3-Hexen-1-ol, linalool, methyl salicylate, geraniol, benzyl alcohol and phenylethyl alcohol. Furthermore, the glycosidic aroma precursors of Zhangping Shuixian tea in 12 manufacturing processes were extracted and identified. The results showed that spring tea and autumn tea have the same type of glycosidic aroma precursors in tea samples from different process, but the content of each component is different. The contents of components in the autumn tea are obviously higher than that of in the spring tea, while the content of glycosidic aroma precursors in withering leaves increase significantly than that in fresh leaves after plucking, the contents of glycosidic aroma precursors changed constantly during all the period of shaking and tossing, it suggested that the dynamic balance of glycosidic synthesis and enzymolysis were existed in this process.