Effect of low-temperature treatment on the physicochemical, interfacial, and foaming properties of wheat gliadin nanoparticles.

Wheat gliadin nanoparticles are promising food-grade foam stabilizers; however, their response to low temperatures remains inadequately characterized. This study evaluated the effects of low-temperature treatment (4, 0, -20, -40, and -80 °C, 15 h) on the microstructure, interfacial behavior, and foaming properties of gliadin nanoparticles. Zeta potential remained within a narrow range (∼14-22 mV) across treatments, whereas particle size increased from 106.13 ± 0.503 nm to 522.83 ± 21.15 nm at pH 5.7 after -80 °C treatment. Gliadin nanoparticles remained interfacially active, especially at pH 5.7, exhibiting a rapid adsorption rate and forming strong viscoelastic films. Foam half-life increased from 3308 ± 39.6 to 4200 ± 169.7, accompanied by thicker lamella from 15.2 ± 1.81 to 21.27 ± 2.89 μm. These findings offer useful insights into low-temperature treatments, particularly at -80 °C, improving foam stability and supporting their future applications in foam-based food systems.