关键词: 茶叶, 香气, 固相微萃取, 吹扫捕集-热脱附, 搅拌磁子吸附, 气相色谱-质谱分析

Abstract: The volatile flavor compounds in Hangzhou Longjing tea, Huangshan Maofeng tea, Shandong Laoshan Mountain tea and Fujian oolong tea were extracted by solid-phase micro-extraction (SPME), purge and trap-thermal desorption (P&T-TD), stir bar sorptive extraction (SBSE), headspace sorptive extraction (HSSE) and analyzed by GC-MS. The major aromatic constituents of tea consisted of vinyls, aldehydes, alcohols, ketones, esters, acids, aromatic compounds, nitrogen-containing compounds, heterocyclic compounds, sulfur-containing compounds, and phenolic compounds. The four varieties of tea were all rich in vinyls, aldehydes, alcohols, and ketones. Although these compounds indicated the largest content in Fujian oolong tea, Hangzhou Longjing tea, Huangshan Maofeng tea and Shandong Laoshan Mountain tea, belonging to the green tea family, contained higher contents of esters and heterocyclic, aromatic and phenolic compounds. The comparison between HSSE-1 and HSSE-2, where nitrogen purging was carried out over tea and below the liquid level of tea infusion, respectively, indicated that the composition and contents of aromatic compounds in tea presented a slight difference before and after being infused. Therefore, tea can reveal dramatic differences in their aromatic components according to different geographic origins and different varieties.

Key words: tea, flavor, solid-phase microextraction (SPME), thermal desorption, stir bar sorptive extraction (SBSE), gas chromatography-mass spectrometry (GC-MS)