Uncovering the key volatile compounds affecting the roasted aroma in sauce-flavor baijiu and their perceptual interactions

ABSTRACT The roasted aroma is a key flavor characteristic shaping the quality of sauce-flavor baijiu (SFB). However, the key volatile compounds responsible for the roasted aroma in SFB and their perceptual interactions remain ambiguous. In this study, SFB samples were categorized into high roasted (HR) aroma and low roasted (LR) aroma groups based on intensity, as determined by quantitative descriptive analysis. Sixteen pyrazines were identified and quantified using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), and the combined application of the aroma activity value method and aroma omission experiments demonstrated that 2,3,5-trimethylpyrazine, 2-ethyl-6-methylpyrazine, and 2-ethyl-3,5-dimethylpyrazine significantly contributed to the roasted aroma ( p < 0.05). A total of 67 principal volatile compounds were identified by headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS) and quantified by gas chromatography flame ionization detector (GC-FID). Esters were found to be the major class of compounds distinguishing HR from LR samples. Multivariate statistical analysis further identified 11 key volatile compounds that effectively discriminated between the two groups. Perceptual interactions between 2-ethyl-3,5-dimethylpyrazine and six volatiles associated with roasted aroma (r > 0.5) were investigated via the σ-τ method, revealing additive or synergistic effects of propionic acid and ethyl propionate on the roasted aroma at different concentration levels.