为探究3个代表性乌龙茶品种关键香气成分,采用搅拌棒吸附萃取结合气相色谱-嗅闻-质谱(gas chromatography-olfactory-mass spectrometry,GC-O-MS)联用技术对黄旦、铁观音、金观音3个代表性乌龙茶品种关键香气成分进行鉴定和描述,结合香气活性值(odor activity value,OAV)、香气特征影响值和感官审评进行对比分析.感官审评表明,3个品种乌龙茶各表现出明显的品种特征香气,黄旦花香显,略带奶香,铁观音花香浓郁,金观音具甜果香,略带木质香.结合OAV及GC-O-MS鉴定结果表明,香叶醇、植醇、茉莉酸甲酯、反式-橙花叔醇、2-壬酮、苯乙醇等物质是黄旦的关键香气成分,赋予黄旦花香清高、奶香显的香气特征;铁观音中的芳樟醇、3,5-辛二烯-2-酮、氧化芳樟醇、顺式茉莉酮、脱氢芳樟醇、α-松油醇等物质呈多元性的花香,与其品种特征香气密切相关;金观音中的关键香气成分包括芳樟醇、藏花醛、香叶基丙酮、顺式茉莉酮、异丁子香酚等物质,是形成其甜果香与木质香品种特征香气的关键物质.
Stir bar sorptive extraction(SBSE)combined with gas chromatography-olfactory-mass spectrometry(GC-O-MS)was used to identify and describe the key aroma components of three representative oolong tea varieties,Huangdan,Tieguanyin and Jinguanyin.Comparative analysis was conducted in terms of odor activity value(OAV),aroma character impact(ACI)value and sensory evaluation.The sensory evaluation showed that each variety showed obvious aroma characteristics.Huangdan oolong tea had an obvious floral aroma as well as a slight milky aroma.Tieguanyin oolong tea had a strong floral aroma.Jinguanyin oolong tea had a sweet fruity aroma as well as a slight woody aroma.According to the results of OAV and GC-O-MS analysis,geraniol,phytol,methyl jasmonate,trans-nerol tertiary alcohol,2-nonone,and phenyl ethanol were identified as key aroma components in Huangdan oolong tea,which provided it with clean and high floral aroma and obvious milky aroma characteristics.In Tieguanyin oolong tea,linalool,3,5-octylodiene-2-one,linalool oxide,cis-jasmonone,dehydrolinalool,and α-terpineol showed diverse floral aromas,which were closely related to the characteristic aroma of Tieguanyin oolong tea.The key aroma components identified in Jinguanyin oolong tea included linalool,canalaldehyde,geranyl acetone,cis-jasmonone and isoeugenol,which were responsible for the characteristic sweet floral and woody aromas of Jinguanyin oolong tea.