Assessing the structural and foaming property changes in egg yolk proteins due to malondialdehyde: Experimental and molecular docking studies.

This study evaluated the effects of varying levels of malondialdehyde (MDA) on the structural and foaming properties of the egg yolk proteins (EYPs), and the interaction between them was explored by molecular docking. The results showed that oxidative modification due to MDA increased the carbonyl content of EYPs by 4.49 times. Simultaneously, the total sulfhydryl content was reduced by 21.47%, and the solubility of EYPs was significantly decreased (p < 0.05). Continuous oxidation disorders the previously ordered structure of EYPs. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that some proteins underwent crosslinking and aggregation with increased MDA oxidation, aligning with changes in particle size and zeta-potential. Moderate oxidation (<1 mmol/L) enhanced the foaming capacity and foam stability of EYPs. Additionally, molecular docking results uncovered favorable interactions between MDA and specific EYPs, primarily through hydrogen bonding. This research offers valuable insights into managing the functional and quality changes of yolk products during processing.

Evaluation of changes in egg yolk lipids during storage based on lipidomics through UPLC-MS/MS.

A comprehensive UPLC-MS/MS-based lipidomics analysis of egg yolk at different storage periods was performed. Through the analysis, 836 lipid species from 27 subclasses were detected, including 159 significantly different lipid species. Glycerolipids (GL) and glycerophospholipids (GP) were the most abundant lipids, followed by fatty acyls (FA), sphingolipids (SP), sterol lipids (ST), and prenol lipids (PR). PCA and OPLS-DA showed that egg yolk lipids changed significantly with prolonged storage. Moreover, glycerophospholipid metabolism and glycerolipid metabolism were key metabolic pathways, as phosphatidic acid (PA), lysophosphatidic acid (LPA), and diglyceride (DG) were key lipid metabolites in the related metabolic pathways of egg yolk during storage. Furthermore, egg yolk quality changed the most when stored up to 21 days. Our study establishes a foundation for the quality control and the lipid oxidation mechanism of eggs during storage.