炒青绿茶香气品质形成过程中芳香物质的动态变化

为探明炒青绿茶香气品质形成过程中香气物质的变化规律,选取福鼎大白茶和黔茶1号1芽2叶制炒青绿茶加工过程样,利用顶空-固相微萃取(HS-SPME)富集香气物质,GC-MS检测分析香气成分。结果表明:鲜叶中香气物质种类单一,香气物质数量较少,芳樟醇、香叶醇等醇类香气物质占比超70%,随着加工工序的展开,茶样中香气物质种类愈加丰富;摊青过程伴随着一定程度的失水和茶叶内部物质的转化,醇类、醛类物质含量降低,酯类、酮类芳香物质含量上升;揉捻过程中福鼎大白茶和黔茶1号的戊醛、青叶醇含量达最高,分别为6.03%、4.14%和4.07%、6.65%;在热作用下,以顺-茉莉酮、吲哚、(E)-4,8-二甲基-1,3,7-壬三烯为代表的高沸点物质在杀青、炒青和烘干过程中含量呈现上升趋势。烘干过程中福鼎大白茶和黔茶1号产生大量的二甲基硫醚,其含量分别为14.08%和19.39%,该物质与青叶醇等一起构成炒青绿茶的新茶香。

Dynamic Variation of Aromatic Components During the Manufacturing Processes of Roasted Green Tea

To explore the change regulation of aromatic components in the manufacturing process of roasted green tea,taking Fudingdabaicha and Qiancha 1 as the samples,the volatile aroma components in tea leaves during the processes of roasted green tea were extracted by headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS).Results:More than 70％ alcohols in tea fresh leaves and with the development of machining process,the types and quantity of aromatic substance remarkably increased.During the withering stage,the content of alcohols and aldehydes decreased.By contrast,the content of esters and ketones increased.The contents of pentanal and leaf alcohol reached the highest during the rolling process,which were respectively 6.03％,4.14％ and 4.07％,6.65％.Under the action of heat,the content of cis-Jasmone,Indole,(E)-4,8-Dimethyl-l,3,7-nonatriene increased accordingly.The content of dimethyl sulfide reached the highest in dying stage,the content of which was respectively 14.08％ and 19.39％ in Fudingdabaicha and Qiancha1,and formed the new tea aroma with leaf alcohol.