普洱市不同产茶区普洱生茶香气成分差异性分析

采用顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)结合气相色谱-质谱联用仪(gas chromatography-mass spectrometry,GC-MS)分别对普洱市5个产茶区的普洱生茶香气组分进行分析。结果表明,42个普洱生茶样品中共检测出83种香气成分,其中醇类化合物23种,碳氢类化合物20种,酯类化合物12种,甲氧基苯类化合物8种,酮类化合物8种,酸类化合物4种,酚类化合物3种,醛类化合物3种,含氮类化合物2种。不同产茶区普洱生茶中醇类、碳氢类和醛类化合物相对百分含量差异均不显著,甲氧基苯类化合物含量差异显著性比例较大,酯类、酮类、酚类、酸类和含氮类化合物含量差异显著性比例较小。以83种香气成分相对百分含量为变量进行偏最小二乘判别分析(partial least squares-discriminant analysis,PLS-DA),不同产茶区的普洱生茶样品呈现明显的分离趋势,变量重要性因子(variable importance in the projection,VIP)分析,33种香气成分对不同产茶区普洱生茶样品区分起主要作用(VIP> 1),33种香气成分中甲氧基苯类、酮类、酯类和醇类物质占比最大。

Comparative Study on The Aroma Components of Raw Pu-erh Tea Among Different Producing Areas of Pu'er City

The aroma components of raw Pu-erh tea samples obtained from five tea producing areas of Pu’er City were analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry(HSSPME-GC-MS). A total of 83 aroma components were tentatively identified in 42 samples,including 23 alcohols,20 hydrocarbons,12 esters,8 methoxy-phenolic compounds,8 ketones,4 acids,3 phenols,3 aldehydes and 2 nitrogen compounds. There was no significant difference in the relative content of alcohols,hydrocarbons and aldehydes in raw Pu-erh tea samples obtained from different producing areas of Pu’er City.The significant difference proportion of methoxy-phenolic compounds was larger,while the significant difference proportion of esters,ketones,phenols,acids and nitrogen compounds was smaller. Partial least squares discriminant analysis(PLS-DA)was conducted with the relative content of 83 aroma components. The raw Pu-erh tea samples obtained from different producing areas showed a distinct separation trend. The variable importance in the projection(VIP) analysis showed that 33 aroma components played a major role in the differentiation of raw Pu-erh tea samples obtained from different producing areas(VIP > 1),methoxy-phenolic compounds,ketones,esters and alcohols accounted for largest proportion in 33 aroma components.