Effects of whey protein isolate heating temperature on formation and stabilization of arabinoxylan-whey protein isolate based Pickering emulsions

Protein-polysaccharide complexes are widely regarded as ideal stabilizers for Pickering emulsions due to their synergistic stabilization mechanisms. Among these, the arabinoxylan (AX) and whey protein isolate (WPI) complex exhibits exceptional emulsification potential. While thermal processing modulates WPI’s aggregation, hydrophobicity, and interfacial film-forming capacity, the influence of WPI’s heating temperature on WPI-AX composite particle formation and subsequent emulsion stability remains unclear. In this study, WPI-AX particles were prepared at varying WPI heating temperatures (unheated, 60°C, 80°C, and 100°C). Their physicochemical properties including particle size, ζ-potential, microstructure, interfacial behavior, and spectroscopic traits were systematically characterized, along with surface hydrophobicity and emulsifying activity. Pickering emulsions stabilized by these particles were then prepared and assessed. Results demonstrated that heating temperature significantly influenced interfacial behavior, protein conformation, and emulsification capacity of WPI-AX composite particles. Emulsions stabilized by WPI-AX composites exhibited excellent stability when prepared with unheated WPI or WPI heated at 60°C or 80°C. In contrast, emulsions with WPI heated at 100°C showed poor stability due to excessive protein aggregation and structural disruption, which increased interfacial tension and weakened hydrogen bonding. This study systematically elucidates the stability evolution of WPI-AX-stabilized Pickering emulsions under thermal processing, offering critical process parameters and technical guidance for industrial applications. • Heating temperature of WPI significantly determines the interfacial properties of resulting WPI-AX composite particles. • Emulsions stabilized by WPI-AX particles (formed with unheated, 60°C-, or 80°C-heated WPI) exhibited excellent stability, whereas those containing 100°C-heated WPI showed significant destabilization. • Provides key thermal processing guidelines for optimizing WPI-AX-based Pickering emulsions.