The sodium hyaluronate/sodium caseinate complex improves the emulsifying stability of EPA algae oil by forming an interface network.

Eicosapentaenoic acid (EPA)-rich algal oil is widely used in functional dairy products due to its favorable functional properties. However, its limited restricts broader application in the food industry. In this work, sodium hyaluronate (SH) was combined with sodium caseinate (SC) to form an aqueous network as an emulsifier for EPA. The binding mechanism between SC and SH was investigated via fluorescence spectroscopy and thermodynamic analysis, revealing that van der Waals forces and hydrogen bonds dominate the SC-SH interaction. When used as an emulsifier, the SC/SH complex effectively encapsulated EPA-rich algal oil. The resulting emulsions exhibited significantly enhanced stability against environmental stresses-including storage, ionic, and oxidative stresses-with more uniform droplet size distribution. The SC/SH complex thus demonstrates potential as a stabilizer for functional lipid-delivery systems.