Quantitative proteomics provides a new perspective on the mechanism of network structure depolymerization during egg white thinning.

As a typical colloidal solution system, egg white (EW) will naturally thin during storage. This paper discussed mechanism of EW thinning and protein depolymerization from the perspective of "protein composition and molecular structure". The results of rheology showed that viscoelasticity of EW declined substantially. Analysis of EW protein in gel system demonstrated that arrangement of EW thermal gel gradually tightened with dissociation of skeleton protein during storage. Molecular characteristics of EW protein in solution showed that particle size and free sulfhydryl content decreased. The increase of disulfide bonds enhanced intermolecular electrostatic force and hindered molecular aggregation, which improved solubility of molecules and reduced surface hydrophobicity. Quantitative proteomic analysis indicated the reduced abundance of β-ovomucin (OVO) might be the direct cause of EW thinning. Notably, some proteins extensively involved in the aggregation of proteins during later storage. The results can provide scientific basis for depolymerization and aggregation of EW during storage.
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