Standardized processing reconfigures regional raw material differences into distinct aroma-active compound profiles in raw Anhua dark tea

Fresh leaves from seven regions were processed under identical conditions. • Processing reshaped aroma composition and amplified regional differences. • OAV and multivariate analysis identified 17 region-specific odorants. • Molecular docking suggested different receptor binding capacities among key odorants. Whether standardized tea processing homogenizes regional raw material differences or reconstructs them into distinct aroma profiles of raw Anhua dark tea (RADT) remains unclear. In this study, fresh leaves from seven regions were processed under identical manufacturing conditions to separate the effects of raw material origin from manufacturing process. Sensory evaluation showed that standardized processing did not eliminate regional aroma differences; instead, the resulting tea infusions retained distinct aroma attributes across regions, including roasty/smoky, stale/woody, floral, fruity, and green/fatty notes. GC-O/MS and quantitative analysis identified 48 odorants in fresh leaves and 82 odorants in RADT infusions, indicating that processing substantially reshaped the aroma composition. Alcohols, aldehydes, and terpenoids derived from fresh leaves generally decreased, whereas processing associated acids, phenols, lactones, and heterocyclics increased. Multivariate analysis identified 45 processing responsive odorants, including newly formed heterocyclics, ( E , E )-2,4-heptadienal, and ( E )- β -ionone. By integrating odor activity value with multivariate discrimination, 17 regional key odorants were identified, demonstrating that standardized processing reconfigured regional raw material differences into distinct aroma-active compound combinations rather than homogenizing them. Molecular docking revealed different predicted binding capacities between representative key odorants and selected olfactory receptors, with cedrol and ( E )- β -ionone showing stronger predicted receptor interactions than smaller linear aldehydes, suggesting that regional aroma differences in RADT may also involve receptor level recognition. Overall, these findings reveal that standardized processing acts as a transformative filter that reshapes regional raw material differences into distinct aroma profiles in RADT. Download: Download high-res image (184KB) Download: Download full-size image