Abstract: In this study, the volatile components and key aroma-active compounds of Gongmei white tea were comprehensively analyzed using two-dimensional gas chromatography-time-of-flight-mass spectrometry (GC × GC-TOFMS) combined with gas chromatography-olfactometry-mass spectrometry (GC-O-MS). A total of 236 volatile compounds were identified, mainly including aldehydes (38.46%) and alcohols (25.58%), and the major volatile components were benzaldehyde (147.27‰), (E)-2-hexenal (90.14‰), linalool (79.80‰), phenethyl alcohol (50.76‰), 2-pentyl-furan (46.23‰), geraniol (39.06‰), methyl salicylate (37.80‰), dimethyl sulfide (36.69‰), decane (31.68‰), hexanal (29.39‰), phenethyl alcohol (25.06‰), and benzyl alcohol (22.15‰). GC-O-MS analysis revealed 26 aroma-active compounds, of which 21 compounds were identified, including nine alcohols, five aldehydes, four ketones, two esters and one aromatic hydrocarbon; and these odorants mostly presented clean (green), fresh, floral, fruity, or sweet aromas. Taken together, the GC × GC-TOFMS and GC-O-MS results showed that high proportions of alcohols and aldehydes responsible for natural green, fresh, floral, fruity, or sweet aromas could form the basis for the aroma characteristics of Gongmei. The results in this study will contribute to in-depth understanding of the aroma quality chemistry of Gongmei, and provide a theoretical guidance for improving the aroma quality of Gongmei in processing practices.

Key words: Gongmei; aroma; white tea; two-dimensional gas chromatography-time-of-flight-mass spectrometry; gas chromatography-olfactometry-mass spectrometry