研究了普洱茶中游离态的香气成分的分析方法,分析了不同渥堆阶段目标成分的变化趋势及原因。试验首先采用标准物质及GC-MS对普洱茶中游离态香气成分进行了定性分析,在此基础上,以癸酸乙酯为内标,用GC法对目标成分进行了定量分析研究,获得的结果重复性好,定量分析准确可靠。然后用建立的SDE-GC分析方法测定了普洱茶不同翻堆阶段中目标游离态香气成分的含量。结果显示:高挥发性香气成分随着渥堆时间的延长,含量总体上呈降低趋势,但芳樟醇在二翻中出现最大值,可能与芳樟醇糖苷含量高有关;1,2,3-及1,2,4-三甲氧基苯含量则相反,总体呈增加趋势,但在第2次翻堆及第3次翻堆时分别出现了极大值,可能与霉菌和酵母菌联合作用有关,二者加快了酚基甲基化反应的进程。

The analytical method of free aroma components in Pu-erh tea was investigated;the change and the corresponding reasons of target components during pile-fermention processes were discussed.First,qualitative analysis in Pu-erh tea was carried out by comparing with standard materials and determined with GC-MS.Then,using ethyl decylate as internal standard,the quantitative analysis of the components was conducted by GC.The results had higher repeatability and accuracy.Second,the contents of free aroma components in samples of different piled-fermentation processes were determined by the constructed method.It was found that the contents of high-volatile components were decreased with prolonging of time during pile-fermentation process.However,linalool was increased to the maximum value at the end of second pile-fermentation.This may be relevant with the high content of linalool glycoside in tea samples.The contents of 1,2,3-and 1,2,4-trimethoxylbenzene were different from the high-volatile one.They are,in overall,increased during pile-fermentation process,and got to the maximum at the ends of the second and third piled-fermentation.This is probably correlated with the intensity of the combining action of mycete and saccharomycete,which accelerated the process of methylation reaction.