The texture formation mechanism of protein-based gel

Abstract

Food texture perception critically influences consumer acceptance through complex physico-sensory transformations. This study investigated the correlation mechanism between the bolus properties, biomimetic mechanical parameters and texture perception of whey protein isolate (WPI)/low-acyl gellan gum (LGG) mixed gels by using biomimetic mastication and multiscale characterization based on oral processing. The results showed that pure WPI and WPI continuous phase gels exhibited rigid-brittle characteristic (peak displacement D_F ≈ 14.7 mm; strain hardening index n_C ≈ 0.16), LGG continuous phase gels showed flexibility (D_F ≈ 20.7 mm; energy recovery ratio≈0.42), and bicontinuous phase gels demonstrated optimal strength-toughness balance (elastic modulus K_B ≈ 16 kPa; fracture toughness A_F≈14.3 kJ/m³). Water retention capacity and energy recovery rate correlated with D_F (r = 0.97), governing springiness and compressibility. For firmness perception, K_B (r = 0.66), n_C (r = 0.72), A_F (r = 0.50) and fracture force F_F (r = 0.50) were key factors. Bolus fragment characteristics strongly correlated with the biting and fracture displacement rate k_D (r = −0.72), indicating brittleness depended on fragmentation behavior. Adhesiveness and cohesiveness synergized with water retention (r = −0.9). Based on this, the sensory evaluation regression model established (springiness: MSE = 0.07, R² = 0.99; cohesiveness: MSE = 0.397, R² = 0.966, etc.) provided a theoretical basis for designing protein/polysaccharide gel textures.