西湖龙井茶HS-SPME/GC-MS香气指纹图谱研究

Analysis of Aroma Fingerprint of Xihu Longjing Tea Using HS-SPME/GC-MS

摘要:

西湖龙井茶产于浙江省杭州市西湖区，是我国传统的历史名茶之一，其香气品质优异，为众多消费者所青睐。采用顶空固相微萃取-气相色谱联用质谱法（HS-SPME/GC-MS）分析了24个西湖龙井茶的香气成分，建立了西湖龙井茶的气相色谱-质谱（GC-MS）指纹图谱。结果表明，本研究中西湖龙井茶香气的HS-SPME最佳萃取条件为采用50/30 μm CAR-DVB-PDMS的萃取头，在60 ℃的水浴温度下萃取30 min。所建立的西湖龙井茶香气成分的GC-MS指纹图谱中共鉴定出24个特征指纹峰，其峰面积占总峰面积的76.20%。采用夹角余弦法和相关系数法对指纹图谱进行了分析，发现24个西湖龙井茶样品具有较好的相似性。聚类分析表明，不同等级的西湖龙井茶样品得到了较好的聚类。GC-MS指纹图谱结合聚类分析法能够对西湖龙井茶的香气质量评价提供科学参考。

Abstract:

Xihu Longjing tea, one of the famous teas of China, has a long history and superior aroma quality, is and originally produced in Xihu district, Hangzhou city, Zhejiang Province. It is greatly favored by many consumers. The aroma components of 24 Xihu Longjing tea samples were investigated by solid phase micro-extraction gas chromatography-mass spectrometry (HS-SPME/GC-MS), and their GC-MS fingerprints were established. Optimal extraction for HS-SPME in this study was achieved with 50/30 μm CAR-DVB-PDMS fiber and extraction for 30 min with a water bath temperature of 60 ℃. In the GC-MS fingerprints established for the aroma components of Xihu Longjing tea, a total of 24 characteristic peaks were identified, and their peak areas accounted for 76.20% of the total peak area. The GC-MS fingerprints were analyzed by cosine and correlation coefficient methods, and a high similarity among different Xihu Longjing tea samples was observed. Cluster analysis demonstrated that Xihu Longjing tea samples with different grades could be grouped into one cluster. Thus, this method, which is based on GC-MS fingerprints combined with cluster analysis, can provide a scientific reference for aroma quality evaluation of Xihu Longjing tea.