Evolution of instrumental flavor profiles in pork with salted vegetable during frozen storage revealed by GC-IMS, E-nose, and E-tongue.

This study investigated the impact of storage duration on the flavor profile of a representative prepared dish, pork with salted vegetable (PSV). E-nose results indicated that the intensity of organic compounds, aromatics, and pungent gases increased with prolonged storage. E-tongue analysis revealed that fresh PSV exhibited the highest sourness and umami, which gradually diminished, while bitterness intensified. A total of 79 volatile compounds were identified, including 33 aldehydes, 8 alcohols, 16 ketones, 10 esters, 1 pyrazine, 1 furan, 3 terpenes, and 7 unidentified compounds. ROAV analysis suggested that several aldehydes and ketones, including pentanal, hexanal, heptanal, n-octanal, n-nonanal, 3-methylbutanal, 2-methylbutanal, 2-phenylethanal, 1-octen-3-one, and 3-penten-2-one, were potential aroma contributors in fresh PSV. Using a Partial Least Squares Discriminant Analysis (PLS-DA) model, 19 compounds with Variable Importance in Projection (VIP) scores greater than 1.0 were identified, mainly aldehydes, ketones, alcohols, and esters. These changes may be associated with lipid oxidation and thermal reaction pathways, although further sensory and chemical validation is required. The experimental results provide instrumental evidence for understanding flavor variation in PSV during storage and may support future studies on flavor quality evaluation in similar prepared dishes.