Abstract: To clarify the material basis and evolutionary pattern of aged aroma formation in black tea under controlled temperature and humidity, a saturated-salt resorption device was used to simulate a specific humidity environment, and Gongfu black tea was subjected to accelerated aging. The effects of different treatment durations (10, 20, and 30 days) on the aroma sensory characteristics and volatile compounds of black tea were investigated. The results showed that the intensities of floral and sweet aroma gradually decreased with prolonged treatment, and the aged aroma became perceptible after 20 days. A total of 89 volatile compounds were identified by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Among them, the contents of 10 compounds responsible for floral and fruity aromas including linalool and indole ethane decreased significantly (by 25.8%–75.1%), whereas the levels of two key aged aroma compounds, 2,2,6-trimethylcyclohexanone and dihydro-kiwi lactone, increased markedly (by 37.5% and 42.6%, respectively). Orthogonal partial least squares discriminant analysis indicated significant differences in volatile profiles among treatments. Based on variable importance in projection (VIP > 1), relative odor activity value (ROAV > 1), and Pearson correlation analysis, dihydro-kiwi lactone and 2,2,6-trimethylcyclohexanone were identified as key compounds regulating aged aroma formation and could be used as core markers to characterize the degree of aged aroma development in Gongfu black tea. This study systematically elucidates the dynamic evolution of key aroma constituents during accelerated aging of Gongfu black tea under controlled humidity conditions, providing theoretical support for the precise regulation of the production process for aged aroma-type Gongfu black tea.

Key words: black tea; artificial accelerated aging; humidity control