Regulatory Mechanism of Humulinone on Protein Foam: applications in whey and pea protein

Foam is one of the most common and important systems in food, contributing to both the visual appeal and sensory experience. This work investigated the impact of humulinone on the foam properties and physicochemical characteristics of two widely used proteins in food systems: whey protein (WP), a traditional animal-derived protein, and pea protein (PP), a novel plant-based protein alternative. The results showed that humulinone significantly enhanced the foamability of both proteins, increasing the foaming capacity of WP by 2.34 times and PP by 1.66 times at a mass ratio of protein to humulinone of 1:0.1, while having limited effect on foam stability. Spectroscopic analysis and molecular docking revealed that humulinone interacted mainly through hydrogen bonding, leading to conformational changes in secondary structure-promoting. Surface tension measurements indicated that humulinone reduced the surface tension of WP and PP, which accelerated the diffusion stage during interfacial adsorption. Additionally, in food matrix models such as milk and commercial pea protein beverages, humulinone showed potential in improving foamability. These findings provide both mechanistic insights and theoretical support for the application of humulinone in foam-based food products.