Interface synergy in aqueous Pickering foams: Effects of food gums and sodium Caseinate on the interfacial properties of fat crystal.

Aqueous Pickering foams offer promising opportunities in the aerated food sector but are often limited by low foaming efficiency and poor long-term stability. Fat crystal (SLPs) derived from fully hydrogenated soybean oil (FH), stabilized with either Tween 40 (FH-T40-SLPs) or sodium caseinate (FH-SC-SLPs), were developed to address these challenges. To better mimic real food systems, food gum (FG), sodium caseinate (SC), and their combinations were incorporated to investigate their effects on particle characteristics, interfacial behavior, and foam performance. FH-T40-SLPs (271.7 ± 1.90 nm) exhibited rough, polyhedral structures with mixed α and β polymorphs, higher viscosity, relying on the formation of rigid, interconnected interfacial crystalline layers and gel-like particle networks to reinforce the interface and enhance both foamability and stability. In contrast, smooth, α-crystal FH-SC-SLPs (289.0 ± 1.40 nm) were more sensitive to additive-induced changes due to flexible, loosely packed interfacial films. FG and SC modulated particle size, zeta potential, and interfacial properties, with FH-T40-SLPs maintaining structural uniformity and forming stable interfacial networks. Foams stabilized by FH-T40-SLPs with FG, SC, or their mixtures exhibited smaller and more uniform bubbles, higher bubble density, and enhanced viscoelastic moduli (G' and G″) compared to FH-SC-SLP-stabilized foams. Notably, the synergistic effects of FG and SC extended foam shelf life from 15 to 45 days by reinforcing interfacial layer formation and stabilizing multilayered fat crystal networks. This work provides insights into designing ultra-stable edible foams using lipid-based Pickering stabilizers and food-grade additives.