Effects of onion skin extract on lipid oxidation and volatile flavor compounds of low-salt dry-cured ham during ripening

This study investigated the effects of integrating a novel low-sodium formula, comprising 70% sodium chloride, 18% potassium lactate, and 12% lysine, into an onion skin extract (OPE)-coated lard system on the nutritional, sensory, and flavor quality of low-salt dry-cured ham onion skin extract (OPE) and compare them to those of the positive control quercetin (QCT). Results showed that the OPE and QCT groups significantly reduced peroxide value (POV) by 35.82% and 25.37%, respectively, and thiobarbituric acid reactive substances (TBARS) by 28.75% and 30%. Furthermore, the application of OPE or QCT significantly decreased the conjugated diene and carbonyl values ( P < 0.05) but increased the unsaturated fatty acid content in dry-cured ham. All samples contained 42 aromatic compounds, with higher amounts of benzeneacetaldehyde, tetradecanal, and heptane detected in the OPE and QCT groups than in the control (CK) group. Moreover, 24 differential metabolites linked to fatty acid biosynthesis and α-linolenic and linoleic acid metabolism were identified. Sensory evaluation showed that OPE significantly improved aroma, taste, and acceptability, though its scores were lower than QCT, consistent with electronic tongue analysis. This study offers a new approach for applying natural antioxidants as coating materials to improve the quality of dry-cured ham products.