Co-decoding dynamics in volatiles and sensory profiles of Zhaiji millet vinegar during aging by integrating multiple flavor characterization techniques and chemometrics

Zhaiji millet vinegar (ZJMV) is a signature acidic condiment. To investigate the effect of aging on the flavor of ZJMV, here gas chromatography–mass spectrometry (GC–MS), gas chromatography-ion mobility spectrometry (GC-IMS), electronic nose, electronic tongue, and quantitative descriptive analysis were used to characterize the flavor profiles of ZJMV for five aging years (2 to 10 years). GS-MS and GC-IMS identified 84 and 44 volatile organic compounds (VOCs), with the most abundant alcohols and esters ( p  < 0.05). Notably, the number of VOCs in the ZJMV gradually decreased with increasing aging time, while the overall concentration peaked in the third year. Sensory evaluation indicated that aging enhanced roasty and umami and moderated other attributes such as spice-like. Additionally, 15 potential flavor markers ( p  < 0.05, variable importance projection ≥1.2) and 23 odor-active compounds (odor activity values ≥1) were screened. Our results provide new insights for improving the ZJMV flavor quality.