Integrated Flavoromics Reveals Breed-Associated Flavor Evolution in Dry-Cured Xuanwei Ham During Ripening

Xuanwei ham (XWH), a Protected Geographical Indication (PGI) dry-cured ham traditionally produced from indigenous Xuanhe pigs, is increasingly threatened by substitution with lower-cost hams made from commercial Duroc × Landrace × Yorkshire (DLY) pigs. This study compared XWH- and DLY-derived ham (DLYH) at 1, 2, and 3 years of ripening using an electronic tongue (E-tongue), an electronic nose (E-nose), gas chromatography-ion mobility spectrometry (GC-IMS), and targeted analysis of nucleotides, free amino acids (FAAs), and free fatty acids (FFAs). The results showed that XWH exhibited stronger umami and greater proteolysis, accompanied by greater accumulation of glutamic acid, whereas DLYH showed greater bitterness. After three years of ripening, XWH contained higher total FFAs, oleic acid, and linoleic acid and maintained a more stable UFA/SFA ratio than DLYH. GC-IMS showed prominent 2,5-dimethylfuran and 2-methylpyrazine in XWH, whereas lipid-oxidation-related 2-heptanone and 1-octen-3-ol were more prominent in DLYH. Partial Least Squares Discriminant Analysis (PLS-DA) clearly separated the six ham groups and identified 30 key discriminant markers. These findings reveal distinct breed-associated flavor evolution during ripening and provide potential chemical markers for the quality evaluation and authentication of XWH.