Characterization of volatile sulfur compounds in soy sauce aroma type Baijiu and changes during fermentation by GC × GC-TOFMS, organoleptic impact evaluation, and multivariate data analysis

An analytical method based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS) was developed to characterize volatile sulfur compounds (VSCs) in soy sauce aroma type Baijiu (SSAB) and soy sauce aroma type rounds Baijiu (SSARB). Using this method, 19 VSCs were identified and quantified. The aroma contribution of VSCs was evaluated by odor activity values (OAVs) and perceptive interactions. Seven VSCs had concentrations higher than their corresponding odor thresholds. In particular, the presence of methyl furfuryl disulfide (OAV: 7-11) and 2-methyl-3-(methyldisulfanyl)furan (OAV: 9-18) with relatively high OAVs in Baijiu was reported for the first time, and they could be the important aroma contributors to SSAB. Moreover, sensory analysis revealed that dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide enhanced the perception of fruity aromas in the matrices studied. Partial least-squares discriminant analysis (PLS-DA) analysis indicated that the VSCs could be used to distinguish SSARB.