# Processing technology as aroma architect: OAV fingerprints decode differentiation and compatibility of key odorants in Fuding Dabai tea via GC×GC-TOF-MS and sensomics

## TL;DR

This study shows how tea processing techniques influence aroma profiles in Fuding Dabai tea, using advanced analytical methods to identify key odorants and their relationships with processing steps.

## Contribution

The study introduces a novel integration of sensomics and GC×GC-TOF-MS to decode aroma differentiation and compatibility in tea processing.

## Key findings

- Fermentation degree is the primary factor driving aroma divergence in tea processing.
- Sweet aroma correlates strongly with benzeneacetaldehyde and (E)-2-hexenal, while aged aroma correlates with (E,E)-2,4-heptadienal.
- Processing techniques reconfigure aroma profiles through enzymatic inhibition, oxidative conversion, and microbial fermentation.

## Abstract

This study systematically investigates the regulatory role of processing technology in the aroma differentiation of Fuding Dabai tea (Camellia sinensis). Using an integrated sensomics approach combining quantitative descriptive analysis and GC × GC–TOF–MS, we deciphered aroma formation in green (GT), white (WT), black (BT), and dark (DT) teas. Among 187 volatiles detected, WT exhibited the highest VOC content (2349.42 μg/L) and the most key odorants (30 of 36). Multivariate statistical modeling identified fermentation degree as the primary factor driving aroma divergence, clearly discriminating fermented (BT/DT) from non/light-fermented (GT/WT) teas. OPLS-DA selected 12 marker compounds (VIP > 1), predominantly alcohols and aldehydes. Sweet aroma exhibited strong correlations with benzeneacetaldehyde (r = 0.91) and (E)-2-hexenal (r = 0.92), while aged aroma correlated strongly with (E,E)-2,4-heptadienal (r = 0.92) (all p < 0.001). We demonstrate that processing reconfigures aroma profiles through enzymatic inhibition, oxidative conversion, and microbial fermentation pathways. These results provide a biochemical basis for aroma-oriented optimization in tea processing and establish the superior suitability of Fuding Dabai for white tea production.

•Processing techniques reshape tea aroma through enzyme inhibition-oxidation-fermentation biochemical axis.•Comprehensive chromatography identified 187 volatile compounds dominated by alcohols and ketones.•Thirty-five key odorants with odor activity values ≥1 show distinct process-specific distributions.•Fermentation extent explained 53.3% variance as dominant factor in aroma differentiation.

Processing techniques reshape tea aroma through enzyme inhibition-oxidation-fermentation biochemical axis.

Comprehensive chromatography identified 187 volatile compounds dominated by alcohols and ketones.

Thirty-five key odorants with odor activity values ≥1 show distinct process-specific distributions.

Fermentation extent explained 53.3% variance as dominant factor in aroma differentiation.