Characterizing sensory defect in Nuodeng ham: Differences in volatile compounds and physicochemical properties from normal ham using GC-IMS and GC-TOF-MS

In the production of Nuodeng ham, sensory defects occasionally occur, yet underlying molecular mechanisms differentiating defective from normal hams remain poorly understood, particularly regarding flavor-related metabolic profiles. To address this gap, this study systematically compared the physicochemical properties, volatile flavor compounds, and small-molecule metabolites between sensory defect (DH) and normal (NH) Nuodeng hams using an integrated approach combining GC-IMS and GC-TOF-MS. Our results revealed that defective hams exhibited higher moisture content, lower salt and nitrite levels, and deteriorated color and texture, with enhanced proteolysis and lipid oxidation. Flavoromics analysis identified 12 volatile markers, among which hexanal and benzeneacetaldehyde were significantly elevated in DH. Metabolomics demonstrated that the accumulation of organic acids and the reduction of flavor amino acids and precursors were associated with defect formation. These findings provide insights into the metabolic basis of sensory defects in dry-cured ham and offer references for flavor quality improvement in traditional meat products. • Differences in quality between sensory defect and normal ham were compared. • The degree of protein hydrolysis and lipid oxidation of defective ham increased. • A total of 12 characteristic flavor markers were screened out. • Amino acids and organic acids were key biomarkers for defective hams. • The formation mechanism of defective ham was summarized and analyzed.