Gelation behavior of egg white protein modulated by polysaccharide charge characteristics: Molecular mechanisms from hydration perspective

This study systematically investigated the regulatory mechanisms of polysaccharides with distinct charge characteristics, including zwitterionic carboxymethyl chitosan, cationic chitosan, anionic carboxymethyl cellulose, and neutral hydroxypropyl methylcellulose, on the heat-induced gelation behavior of egg white protein. A combination of rheological measurements, water state analysis, texture characterization, and microscopic imaging was employed. The results demonstrated that anionic, cationic and neutral polysaccharides delayed gelation while promoting the development of tightly structured three-dimensional networks. In contrast, zwitterionic polysaccharides uniquely reduced gelation temperature and modified hydrogen bond distribution, thereby significantly enhancing water-holding capacity and producing softer gel textures. At the molecular level, it was found that the charge characteristics of polysaccharides influenced gel properties through two mechanisms involving the modification of system hydration states and the regulation of intermolecular interactions. These findings provide new insights into polysaccharide-protein interactions and offer potential strategies for precise texture modulation in protein-based food systems.