祁门红茶的香气特征

通过对祁红当家品种——槠叶群体种及其适制绿茶的亲缘种——安徽7号(对照)在加工红茶的过程中香气形成的动态分析和比较研究表明,在祁红检出的110多种香气成分中,己醛,1-戊烯-3-醇、反-2-己烯醛、顺-3-己烯醇、芳樟醇氧化物Ⅱ、芳樟醇、香叶醇、橙花叔醇等含量较高。在相同的祁红加工过程中,槠叶群体的香气物质形成总量高于对照,且形成高峰超前,其中香叶醇含量在揉捻阶段剧增;与安徽7号相比,香叶醇含量高出30倍以上,而其他香气成分含量则无明显差异。实验还发现,两品种茶叶在加工过程中,儿茶素的减少与茶叶香气总量及其中的萜烯醇类的增长均具有很好的对应关系,槠叶群体中有关香气配糖体的含量高于安徽7号,文中对此作了讨论。

Characteristic Aroma Components of Qimen Black Tea

The characteristic aroma components of Qimen black tea which wasmade by Zhuye population and changes of the aroma components duringthe processing procedures were investigated by GC and GC/MS.The maincomponents of the Qimen black tea were hexanal,1-penten-3-ol,(E)-2-hexenal,(Z)-3-hexenal,linalool oxide Ⅱ,linalool,geraniol and nerolidol.During the processing procedures,the content of geraniol was increased 28times in contrast to that in the steamed leaf at rolling procedure.Theresults were compared with Auhui No.7 variety grown in the same area.Thearoma compoments were not so much difference between Zhuye populationand Anhui No.7 variety,except for geraniol.The former contained above 30times of geraniol as much as the latter.Upon the experimental results,geraniol was considered to be responsible for the characteristic aroma ofQimen black tea,and it might be released from glycosidicallybound geraniolthrough enzymatic hydrolysis.