Effect of rainy-day harvesting on the aroma profile of Wuyi rock tea based on GC-MS and chemical analysis.

Wuyi Rock Tea (WRT), a premium oolong tea, exhibits weather-dependent aroma profiles due to environmental influences during processing. This study investigated volatile organic compounds (VOCs) in WRT produced under sunny and rainy conditions using HS-SPME-GC-MS. A total of 132 VOCs were identified, with significantly higher concentrations in sunny day samples. Alcohols, aldehydes, and aromatics dominated the volatile profiles. Orthogonal partial least squares discriminant analysis (OPLS-DA) revealed 15 key discriminators (VIP > 1), including geraniol and linalool, driving aroma divergence. Odor activity value (OAV) prioritization identified 13 aroma-active compounds (OAV > 1), with β-ionone (floral) and (E)-nerolidol (ripe fruity) as major contributors to WRT's floral-fruity attributes. Rainy conditions reduced critical volatiles by 40-70 %, correlating with sensory-documented aroma dilution and increased astringency. These findings elucidate climate-driven metabolic shifts in WRT aroma formation, emphasizing the need for weather-adaptive processing strategies to optimize tea quality.