Effect of Roasting Time on Aroma Quality of Shuixian Wuyi Rock Tea (Camellia Sinensis)

Roasting is an important process in determining the quality of Wuyi rock tea (WRT). This study used the traditional charcoal roasting method at 120 ± 5°C to process Wuyi Shuixian raw tea. The roasting process lasted 12 h, with samples collected at 2 h intervals (0~12 h). The aroma compounds of the different roasting time samples were analyzed using comprehensive two-dimensional gas chromatography-olfactory-mass spectrometry (GC×GC-O-MS) technology. 21 key aroma-active compounds were identified through aroma extraction dilution analysis (AEDA) and odor activity value (OAV). Multivariate statistical analysis identified ten key differential aroma active compounds to distinguish aroma differences in tea samples with varying roasting times. These compounds include phenylacetaldehyde, linalool, β-ionone, 2,2,6-trimethylcyclohexanone, 6-methyl-5-hepten-2-one, octanal, (E)-nerolidol, 2-ethyl-5-methylpyrazine, β-myrcene, and pentanal. The aroma characteristics of Wuyi Shuixian tea (WSXT) were significantly impacted by roasting time. Through the integration of electronic nose technology and descriptive sensory analysis, the optimal roasting time was 10 h. These results provided valuable insights for enhancing the production process of WSXT.