Objective Key aromatics of the signature orchid-fragrance of the famed Wuyi rock tea were analyzed.

Methods Aromatics in 7 Wuyi Shuixian tea samples were tested by quantitative descriptive analysis (QDA) using the headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS).

Results A total of 677 volatile metabolites were identified in the samples. The chemicals included mostly esters, terpenes, aldehydes, and heterocyclic compounds. Among them, 23 imparting floral and fruity scents, which made up the basis of Wuyi Shuixian tea aroma, were indole, β-ionone, benzaldehyde, decyl acetate, benzyl alcohol, geraniol, and dehydrolinalool. There were 115 compounds with an odor activity value (OAV) greater than 1, and 5 of them significantly correlated with the intensity of the orchid-fragrance (P＜0.05) according to the K-means clustering, OPLS-DA modeling, and correlation analysis (|Cor| ≥ 0.70). They were linalool (OAV=12.06-25.91), geraniol (OAV=162.59-437.92), (Z)-dec-2-enal (OAV=1.20-3.18), (Z)-2-methylbutyl 2-methylbutyrate (OAV=5.14-13.16), and 8-nonenal (OAV=985.59-2503.44), and consequently, could serve as markers for the characteristic aroma of Wuyi Shuixian tea.

Conclusion Chemistry of the distinctive orchid-fragrance of the acclaim Wuyi Shuixian tea was detailed by the HS-SPME-GC-MS analysis to aid the product quality assessment.