Abstract

Protein-protein and protein-water interactions, which sequentially determines texture, macroscopic homogeneity of protein-based products, are closely associated with the aqueous diffusion rate of soy proteins. In this study, the particle size evolution and diffusion kinetics of eight commercial soy protein isolates (SPIs) were modeled in an aqueous system under continuous stir and combined ultrasonic perturbations. A first-order exponential kinetic model, D(t) =D_∞+(D₀−D_∞)×e^{− k(t− t0 )}, was selected as a parsimonious model for describing particle size evolution after comparison with alternative empirical kinetic models. Pearson correlation analysis revealed that the rate of approaching equilibrium particle size of stir (k_stir) or that stir combined ultrasonication (k_us) exhibited significant correlations with the initial particle size, water-holding capacity (P<0.05). Stepwise regression analysis identified calcium content as the major positive statistical predictor positively associated with kstir, whereas disulfide bond content was the major negative predictor of k_us. Δk = (k_us − k_stir) /(k_us + k_stir), was formulated to compare the differential responses of SPI aggregates to stirring and ultrasonication Based on this index, hierarchical cluster analysis grouped the tested SPIs into three kinetic response patterns, descriptively termed. “weak non-covalent dominated” (Δk > 0.2), “strong non-covalent-dominated” (Δk < 0), and “covalentdominated” (0< Δk <0.2). These findings suggest that the kinetic parameters of particle size evolution under sequential physical perturbations, when interpreted together with physicochemical indicators, can provide a phenomenological descriptor associated with the structural heterogeneity and aqueous diffusion behavior of commercial SPI aggregates.

Food Hydrocolloids.August 2026,IF=13.8

DOI:10.1016/j.foodhyd.2026.113238