Molecular mechanism of protein-lipid interactions in steamed egg gelation and deterioration: A quantitative proteomic...

Steamed egg (SE), a traditional egg dish, exhibits steaming time-dependent textural properties. This study investigated the molecular mechanisms underlying SE gel formation and deterioration using quantitative proteomics combined with physicochemical characterization. Results showed optimal gel formation at 11 min steaming, while prolonged steaming (23 min) led to gel cracking and sensory deterioration. Textural analysis showed the hardness of SE increased continuously with the increase of steaming time, but the water-holding capacity decreased significantly. Quantitative proteomic analyses revealed that lysozyme and ovomucin may play a key role in SE formation by influencing protein aggregation through their chargeability and high glycosylation. In addition, the extension of the steaming time disrupted the structure of apolipoproteins, especially low-density lipoprotein (LDL), under the influence of NaCl. The protein parts of LDL were partially involved in the gel structure while the lipid parts were partially free, which might be the main reasons for the creation of voids in the egg custard gels and the decrease of the water-holding capacity. Our findings provide molecular insights into SE gel formation and deterioration, offering theoretical guidance for improving the texture of commercial SE products.