Enhancing the physicochemical and textural properties of goat milk yogurt using Cordyceps militaris polysaccharide and polymerized whey protein composite hydrogels

This study investigated the physicochemical and textural improvement of goat milk yogurt using composite hydrogels prepared from polymerized whey protein (PWP, 10 %, w/v) and Cordyceps militaris polysaccharides (CMP, 0–6 %, w/v). Goat milk yogurt typically suffers from a weak gel network, low water-holding capacity, and poor texture. Increasing CMP concentration enlarged the hydrogel particle size by 41.7 ± 0.54 nm to 86.1 ± 2.70 nm (+147.3 %) and enhanced its stability, as indicated by higher absolute zeta potential (−32.4 mV to −50.8 mV) and improved thermal resistance (endothermic peak: 86.3–114.3 °C). Microscopy revealed a denser and more ordered three-dimensional porous network. Simultaneous rheology and Fourier transform infrared spectroscopy analysis showed stronger hydrogen bonding (amide I band shift: 1636 to 1631 cm −1 ), while molecular interaction and correlation analyses confirmed hydrogen bonding and hydrophobic interactions as the main forces. Incorporating PWP-CMP into goat yogurt delayed acidification and improved water-holding capacity (54.56 ± 2.60 % to 57.2 ± 1.41 %) and improved viscosity, viscoelastic behavior, and textural behavior. These findings demonstrate that CMP promotes the formation of stable PWP hydrogels and effectively alleviates the weak gel network and poor water-holding capacity of goat yogurt, providing a feasible strategy to enhance its physicochemical and textural quality. • Simultaneous rheology and infrared spectroscopy monitored structural evolution of protein-polyaccharide hydrogel. • Two-dimensional correlation spectroscopy resolved spectral overlaps and confirmed intermolecular hydrogen bonding. • Molecular docking revealed stable protein-polyaccharide binding by multiple hydrogen bonds. • Composite hydrogel improved yogurt water retention and stability, enhancing product quality.