关键词: 绿茶, 新陈茶鉴定, 陈气物质, 气质联用法

Abstract: For the purpose of studying and confirming the characteristic aromatic components of stale tea to distinguish the new green tea from the stale Wenzhou green tea, the simultaneous distillation extraction—gas chromatography—mass spectrometry (SDE-GC/MS) was used to analyze seven kinds of tea samples from seven areas of Wenzhou. The results showed that (z)-2-penten-1-ol, 2,4-Heptadiene-1-al and 3,5-Octadien-2-one were not detected in the new tea, however, the three compounds could be detected and reveal a regular increasing tendency with the tea getting stale by going through normal temperature storage, refrigerated storage and frozen storage. Especially, the relation between the content of (z)-2-penten-1-ol and storage duration differed significantly under different storing condition. By employing research instruments such as standard curve, recovery rate, precision and detecting limit, we found that (z)-2-penten-1-ol could be an effective distinguishing indicator of new and stale tea, and 2,4-Heptadiene-1-al and 3,5-Octadien-2-one could be used as auxiliary identifying material, which laid the theoretic foundation of and provided data support to the identification of new and stale Wenzhou green tea.

Key words: green tea, identification of fresh and stale tea, stale tea aroma, GC/MS