Structure-dependent regulation of cod protein interfacial behavior and interfacial proteome by lipid oxidation-derived aldehydes.

Lipid oxidation is a common phenomenon in aquatic multi-interface food systems, and the reactive aldehydes generated are considered key factors affecting protein functionality and system stability. However, existing studies have primarily focused on bulk phase, leaving a lack of systematic understanding of how lipid oxidation-derived aldehydes with varying structures regulate protein interfacial behavior and interfacial-enriched protein composition. This study systematically investigated the effects of different lipid oxidation-derived aldehydes on the oil-water interfacial behavior and interfacial-enriched protein composition of cod protein (CP). Interfacial adsorption kinetics and extensional rheological analyses revealed that aldehyde structure significantly influences protein diffusion, penetration, and rearrangement at the interface. Among these, 4-hydroxy-2-nonenal (HNE), characterized by its hydrophobic long chain and reactive functional groups, exhibited stronger interfacial regulatory capacity compared to acrolein (ACR), significantly enhancing protein adsorption and reshaping the viscoelastic properties of interfacial films. Furthermore, we innovatively conducted untargeted quantitative proteomics analysis of interfacial-enriched protein and non-adsorbed protein in the simulated system, revealing that CP exhibits distinct selective adsorption characteristics at the oil-water interface. HNE treatment increased the abundance of interfacial-enriched protein and significantly altered interfacial-enriched protein composition, whereas ACR primarily disrupted the equilibrium of protein distribution between the interface and the aqueous phase. GO enrichment analysis indicated that the differentially regulated proteins were mainly associated with membrane targeting, protein localization, and myofibril assembly. These results suggest that lipid oxidation-derived aldehydes synergistically regulate the formation of CP interfacial films through structure-dependent protein modification and interfacial enrichment effects, providing new insights into the oxidative instability mechanisms in aquatic product.