3个不同地域龙井茶香气组成异同的解析

Analysis on Similarities and Differences of Aromatic Composition in Longjing Teas from Three Producing Regions

选西湖产区、钱塘产区和越州产区12个龙井茶,以SDE法提取茶叶香气,用GC-MS配合标准样品定性和定量分析,再以聚类分析探讨产区之间茶叶香气组成及含量的差异。分析结果表明:西湖产区龙井茶香气组分的数量较多、香气含量较高,尤其是芳樟醇、己酸叶醇酯、β-紫罗兰酮、橙花叔醇、苯甲醛、壬醛、香叶醇、雪松醇和反式呋喃型芳樟醇氧化物9种重要香气组分的含量较高。以这9种组分的含量为变量,以茶样为实体,作聚类分析。将13个茶样分为两组,来自西湖产区的6个龙井茶样和来自钱塘产区、越州产区的茶样各1个茶样聚为一组;其余5个茶样聚为一组。双浦镇虽属于西湖产区,但该地龙井茶香气和西湖产区的龙井茶样有一定差异;敬亭绿雪不能和西湖产区龙井茶聚为一类。据此认为:(1)原产地的西湖龙井茶香气的成分多、含量丰富;钱塘产区和越州产区龙井茶香型比较接近,各有一个优质茶样与西湖产区龙井茶聚为一类;敬亭绿雪距离原产地远,其香气组成与西湖产区龙井茶差别大。(2)可以选用合适参数,再以多元分析方法明确揭示几个茶区龙井茶香气的差异。

Twelve tea samples were chosen from Xihu producing region, Qiantang producing region, and Yuezhou producing region. Their essential oils were extracted by SDE （Simultaneous Distillation and Extraction） method, and qualitatively and quantitatively analyzed by GC-MS, and combined with the retention time of the authentic standards. In succession, similarities and differences of aromatic composition of them were analyzed by cluster analysis. The results showed that the aroma of Longjing teas from Xihu producing region held the most individual number and the most contents of the aroma compounds within the three producing regions, especially, with abundant typical component linalool, cis-3-hexenyl caproate, β-ionone, nerolidol, benzaldehyde, nonanal, geraniol, cedrol, trans-furanoid linalool oxide. By using the 9 components as variables and 13 tea samples as entities, a cluster analysis was conducted, which divided the 13 tea samples into 2 groups. The 6 tea samples from Xihu producing region clustered together as a group, which still contained one tea sample from Qiantang producing region and Another tea＆amp;nbsp;sample from Yuezhou producing region. The other 5 tea samples clustered together as another group. Although Shuangpu Town belonged to Xihu producing region, the aroma of its tea samples were different from those of other 6 tea samples from Xihu producing region. Oblate shaped tea-Jintinglvxue could not be clustered into Xihu producing region group. It was regarded that： （1） Xihu Longjing teas from the original production place held the most individual number and the most abundant contents of aromatic components than those from other producing regions. The aromatic style of Qiantang producing region appeared similarly with that of Yuezhou producing region, in which one or two tea samples were high grade and similar with Xihu Longjing tea, accordingly, included into Xihu Longjing group, the production place of Jingtinglvxue tea was far from that of Xihu Longjing tea, and its aromatic style was obviously different from that of Xihu Longjing tea. （2） the difference among the aroma of Longjing teas from the several producing regions can be disclosed based on the appropriate parameters and multivariate analysis.