Synergistic Interactions of Polymerized Whey Protein and Okra Polysaccharide: Combining Molecular Dynamics and Simultaneous Rheology and FTIR for Designing Enhanced Functional Goat Milk Yogurt with Sensory Profiling

The present study aimed to investigate the gel characteristics of hydrogels formed by 10% (w/v) polymerized whey protein (PWP) and 0-0.75% (w/v) okra polysaccharide (OPS) through heat-induced gelation. The potential application of these hydrogels as thickening agents in goat yogurt was also assessed. Results demonstrated that the addition of OPS promoted the formation of a stable three-dimensional network structure in the PWP-OPS hydrogels, mediated by hydrogen bonding and hydrophobic interactions. Simultaneous rheology and FTIR spectroscopy analysis revealed conformational changes and the burial of aromatic amino acid residues during the heating process. Molecular docking and molecular dynamics simulations further confirmed the spontaneous polymerization and stable complex formation between PWP and OPS. The PWP-OPS hydrogels exhibited superior physicochemical properties and gelation characteristics compared to the individual components. When applied in goat milk yogurt, the incorporation of 1% PWP-OPS hydrogel (comprising 10% PWP and 0.75% OPS) significantly improved (P < 0.05) the texture, sensory attributes, and microstructure, as determined by texture profile analysis, electronic nose and tongue, and scanning electron microscopy. These findings provide a fundamental theoretical basis for the development and application of protein-polysaccharide hydrogels in dairy products.