Rapid characterization of the volatile profiles in Pu‐erh tea by gas phase electronic nose and microchamber/thermal extractor combined with TD‐GC‐MS

Abstract Aroma plays an important role in the quality of Pu‐erh tea. However, the quality evaluation of Pu‐erh tea aroma is heavily relied on the experience of sensory evaluation, and the theoretical research is relatively scarce. In the present work, the volatile compounds in Pu‐erh tea were characterized by using gas phase electronic nose (e‐nose) and microchamber/thermal extractor (µ‐CTE) combined with thermal desorption coupled to gas chromatography‐mass spectrometry (TD‐GC‐MS). A satisfactory discrimination model ( R 2 Y = 0.95, Q 2 = 0.807) was obtained by using orthogonal partial least squares discriminant analysis (OPLS‐DA) based on the odor fingerprint of different brands of Pu‐erh tea. In addition, based on the double criterion of multivariate analysis with VIP >1.0 and univariate analysis with p ≤ 0.001, 39 volatile components were identified to contribute greatly to the discrimination of five brands of Pu‐erh tea. The results suggested that gas phase e‐nose and µ‐CTE combined with TD‐GC/MS were simple, rapid techniques to characterize the volatile compounds in Pu‐erh tea and were allowed to effectively distinguish different brands of Pu‐erh tea, which would provide an important reference on the quality assessment of Pu‐erh tea. Practical Application This work demonstrates that the volatile compounds in Pu‐erh tea are simply and rapidly characterized by using µ‐CTE/TD‐GC/MS and gas phase e‐nose, allowing to effectively distinguish different brands of Pu‐erh tea, which can provide an important reference for the quality assessment and authentication of Pu‐erh tea.