顶空固相微萃取-气质联用法测定不同陈化时间普洱茶香气成分

Determination of aroma components of aged Pu-erh tea with different storage years based on solid phase microextraction-gas chromatography-mass spectrometry

目的测定不同陈化时间普洱茶的挥发性组分。方法采用顶空-固相微萃取-气质联用法（SPME-GC/MS）测定18个普洱茶挥发性物质。结果从18个普洱茶中共鉴定出98种挥发性物质,包括14种甲氧基酚类、11种醛类、15种醇类、13种酮类、4种酯类、2种呋喃类、2种含N化合物、35种碳氢化合物及2种其他类物质。陈化时间短（4年）的普洱生茶中醇类（31.01%）和碳氢化合物（22.92%）含量高,甲氧基酚类化合物含量低（1.3%）,具有明显的晒青毛茶香气特征。陈化时间长（≥25年）的普洱生茶和普洱熟茶聚成一类,这类普洱陈茶甲氧基酚类化合物含量高（7.52%-39.17%）,且不同陈化时间的普洱茶样本之间香气特征相似,仅通过香气无法推断其陈化时间。结论本研究为消费者正确认识和收藏普洱茶提供一定的参考依据。

Objective To study the volatile compounds of different aged Pu-erh teas. Methods The volatile components were analyzed by solid phase microextraction（SPME） combined with gas chromatography-mass spectrometry（GC-MS）. Results It showed that a total of 98 volatile compounds were identified by matching EI mass spectra and retention indices with the literature data, including 14 methoxy-phenolic, 11 aldehydes, 15 alcohols, 13 ketones, 4 esters, 2 furans, 2 N-containing compounds, 35 hydrocarbons and two others compounds. Aged Pu-erh tea with short storage year（4 years） contained a lot of alcohols（31.01%） and hydrocarbons（22.92%）, while the content of methoxy-phenolic compounds was low（1.3%）, which exhibited drying green raw tea aroma characteristics. Aged Pu-erh raw tea with long storage year（≥25 years） were gathered into a class with Pu-erh ripened tea, which contained high levels of methoxy-phenolic compounds（7.52%-39.17%）, and the aroma characteristics of different Pu-erh teas were similar, which indicated that it was difficult to deduce the concrete storage year of aged Pu-erh raw tea according to the aroma characteristics solely. Conclusion This study provides useful information to objectively evaluate the quality and commercial value of aged Pu-erh teas with different storage years.