Effects of sodium hyaluronate with different molecular weights on whey protein-sodium hyaluronate complexes and...

Whey protein is widely used in yogurt, fermented milk, and other formulated dairy products, but its applications are often limited by phase separation, weak gel structure, and insufficient stability during processing and storage. This study evaluated the effects of sodium hyaluronate with different molecular weights and concentrations on whey protein-sodium hyaluronate complexes, emulsion gels, and their application in yogurt. Sodium hyaluronate interacted with whey protein through noncovalent forces, including electrostatic interactions and hydrogen bonding, and altered protein conformation and interfacial characteristics. Among the tested concentrations, 0.8% sodium hyaluronate provided the best interfacial performance and was selected for subsequent emulsion gel and yogurt experiments. The resulting emulsion gels showed predominantly elastic behavior and shear-thinning properties, and their viscosity, gel strength, and network-forming capacity increased with sodium hyaluronate molecular weight. When incorporated into yogurt, these emulsion gels improved texture and water-holding capacity, with the greatest improvement obtained from sodium hyaluronate with a molecular weight of 800 to 1,500 kDa. Under the formulation and processing conditions tested, these results demonstrate that regulating sodium hyaluronate molecular weight can improve the structure, gel functionality, and yogurt application performance of whey protein-based dairy systems.