The effect of heat and pressure treatment at different pH levels on the foaming properties and surface properties of soy protein isolate and mung bean protein

This study explored the effect of hot-pressing soybean and mung bean proteins at different pH values on their structural, interfacial, and foaming properties. Hot-pressing enhanced the protein foaming capacity at all pH values without affecting stability. At pH 5, isoelectric precipitation caused protein aggregation and increased the particle size, turbidity, and sedimentation. This led to less efficient protein adsorption on the air-bubble surfaces and a lower foaming capacity. Spectroscopy showed that proteins were more flexible under alkaline conditions, reducing the air - water surface tension and increasing the foaming capacity. Optimizing the treatment pH allows hot pressing to improve the foaming properties of plant proteins, thereby expanding their application in the food industry.