Key Laboratory of Tea Biology and Resource Utilization of Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Key Laboratory of Tea Biology and Resource Utilization of Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China.
Food Chem. 2021 Jun 1;346:128906. doi: 10.1016/j.foodchem.2020.128906. Epub 2020 Dec 24.
Various dark teas are quite different in their volatile profiles, mainly due to the huge differences in the phytochemical profiles of dark raw tea and the diverse post-fermentation processing technologies. In this study, gas chromatography-mass spectrometry (GC-MS), qualitative GC-olfactometry (GC-O), and enantioselective GC-MS coupled with multivariate analysis were applied to characterise the volatile profiles of various dark teas obtained from the same dark raw tea material. A total of 159 volatile compounds were identified by stir bar sorptive extraction (SBSE) combined with GC-MS, and 49 odour-active compounds were identified. Moreover, microbial fermentation could greatly influence the distribution of volatile enantiomers in tea, and six pairs of enantiomers showed great diversity of enantiomeric ratios among various dark teas. These results suggest that post-fermentation processing technologies significantly affect the volatile profiles of various dark teas and provide a theoretical basis for the processing and quality control of dark tea products.
不同的黑茶在挥发性成分上有很大的不同，主要是由于黑茶原料的植物化学特征和不同的后发酵加工技术存在巨大差异。本研究采用顶空固相微萃取结合气相色谱-质谱联用技术（HS-SPME-GC-MS）、定性气相色谱-嗅闻技术（GC-O）和手性气相色谱-质谱联用技术（Chiral-GC-MS）结合多元分析方法，对同一种黑茶原料加工得到的不同黑茶的挥发性成分进行了分析。通过顶空固相微萃取结合气相色谱-质谱联用技术共鉴定出 159 种挥发性化合物，其中 49 种为嗅感活性化合物。此外，微生物发酵可以极大地影响茶叶中挥发性对映体的分布，并且有 6 对对映体在不同黑茶中的对映体比值具有很大的多样性。这些结果表明，后发酵加工技术对不同黑茶的挥发性成分有显著影响，为黑茶产品的加工和质量控制提供了理论依据。
