Aggregation regulation and foam stability in ovalbumin-lysozyme systems under alkali-heat treatment and charged amino acids.

This study employed Ovalbumin-Lysozyme (OVA-Lz) complexes as a model system to investigate the effects of alkali-heat treatment combined with charged amino acids on foaming behavior, interfacial properties, and foam destabilization mechanisms. Foaming properties, foam half-life, foam microstructure, foam rheology, surface tension, interfacial protein content, and QCM-D responses were evaluated. Alkali-heat treatment induced the conversion of OVA into S-ovalbumin (S-OVA), increasing molecular flexibility and surface hydrophobicity. S-OVA exhibited a higher foaming capacity than native OVA, whereas Lz addition markedly reduced the foam stability and half-life of the S-OVA system. Basic amino acids suppressed excessive aggregation, improved complex dispersion and foam structural integrity, and prolonged foam half-life, whereas acidic amino acids had limited effects on foam stability. The combined analyses suggested that foam stability was closely associated with the continuity, viscoelastic response, and dynamic restructuring ability of the foam/interfacial structure, rather than being determined solely by the amount of protein associated with the foam phase. This study further links aggregation regulation with foam functionality, providing a theoretical basis for balancing thermal stability and functionality in protein-based foams.