Flavor deterioration and texture changes in mud-packing salted egg yolks: A role of lipid oxidation and fatty acid degradation.

Mud-packing, a traditional salting technique using clay-salt paste, imparts unique characteristics to salted duck egg yolk, yet its impact on storage stability remains understudied. This study investigated quality changes in cooked mud-packing salted duck egg yolks during 28-day ambient storage via integrated physicochemical, structural, and flavor analyses. Extended storage caused significant deterioration: salt content rose from 1.50 ± 0.28% to 2.14 ± 0.35%, moisture fell from 37.36 ± 1.24% to 32.35 ± 0.42%, and hardness increased sharply to 2087.19 ± 78.55 g. Yolk granules compacted, oil exudation decreased, lipid oxidation intensified, and polyunsaturated fatty acids (e.g., DHA, ARA) declined significantly. Volatile profiling revealed reduced desirable esters and alcohols, with increased off-flavor aldehydes and ketones. Oxidation-driven lipid and protein degradation primarily underlies quality decline. These findings emphasize controlling storage time and provide a basis for shelf-life determination, packaging optimization, and quality monitoring in industrial production.