关键词: 西湖龙井茶, 钱塘龙井茶, 越州龙井茶, 香气差异, 聚类分析

Abstract: 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 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 roducing regions can be disclosed based on the appropriate parameters and multivariate analysis.

Key words: Xihu Longjing tea, Qiantang Longjing tea, Yuezhou Longjing tea, difference in aromatic style, cluster analysis