The Dynamic Change of Aroma Substances of Black Tea during Processing

以桃源大叶种茶鲜叶为原料，按照经典红条茶加工工艺将其加工成红条茶，采用同时蒸馏萃取法(SDE)制备精油及GC-MS分析方法，研究其加工过程中香气物质的动态变化，以期为高香红条茶的加工提供参考。结果表明，加工成的红条茶共有110种香气组分，相对含量较高有22种，其中醇类9种，脂肪酸类3种，醛类5种，脂类3种，酮类2种；萎凋期间，醇类、脂类香气组分的相对含量逐渐增加，醛类、酮类、烃类、酸类香气组分的相对含量则逐渐下降；揉捻期间，醇类、酯类、醛类、酮类香气组分的相对含量递增，酸类、烃类香气组分的相对含量下降；发酵期间，醇类、醛类、酮类香气组分的相对含量持续增加，而酯类香气组分的相对含量先增后降，烃类和酸类香气组分的相对含量小幅下降；干燥期间，各类香气物质相对含量均下降。总体而言，从萎凋开始到发酵中后期，红条茶特征香气组分的相对含量呈逐渐增加趋势，而从发酵后期至干燥结束则呈逐渐降低趋势，在生产实际中，可通过适当延长萎凋时间、缩短发酵后期时间及干燥时间，有利于加工高香红条茶。 The black tea processed with traditional technology by Taoyuan leaves was used as the research object, and the aroma components were analyzed by simultaneous distillation and extraction (SDE) combining GC-MS technique, which provided reference for the processing of high-aroma black tea. The results show that the differences of aroma components of black tea were studied by chemical analysis. 110 species of aroma components were detected by GC-MS in totally, and 22 of them were high in content, including 9 types of alcohols, 3 types of fatty acids, 5 types of aldehydes, 3 types of lipids and 2 types of ketones. During the withering period, the relative content of alcohols and lipids increased gradually. The relative content of aldehydes, ketones, hydrocarbons and acids gradually decreased. The relative content of alcohols, lipids, aldehydes, and ketones showed an increasing trend during the period of rolling, and the relative content of acids and hydrocarbons decreased. During the fermentation period, the relative content of alcohols, aldehydes and ketones continued to increase, and the relative content of lipids was first increased and then decreased by the end of fermentation, and the relative content of hydrocarbons and acids decreased slightly. During the drying period, the relative content of all kinds of substances is decreased. As whole, from the beginning of the withering to the middle and late of fermentation, the relative content of characteristic aroma of black tea gradually increased, and then decreased from the later stage of fermentation to the end of drying. In the production, it is conducive to the processing of high-aroma black tea by moderately prolonging the withering time, shortening the time of late fermentation and drying.