Adsorption kinetics of ovalbumin and lysozyme at the air-water interface and foam properties at neutral pH

The dynamic adsorption properties of ovalbumin and lysozyme at the air-water interface and the macroscopic foam properties at neutral pH were reported in this work. The maximum turbidity (81.32%) was observed at a 5:5 ratio of ovalbumin to lysozyme, which might imply a more stable foam structure. This conclusion was corroborated by the results of zeta potential analysis. Furthermore, it could be inferred from the results of UV-Vis and CD spectra that appropriate ovalbumin/lysozyme ratio was essential for the relaxation of the spatial structure of the protein complex as well as the mechanical structure of the interfacial composite protein membrane was dynamically changing. By intrinsic fluorescence spectroscopy, ovalbumin/lysozyme ratio was found to be closely related to the polarity of the microenvironment in which the tryptophan was located. The molecular flexibility results confirmed the conclusion of the foam properties analysis that the ratios of 3:7 and 5:5 had the maximum foam capacity (135.0%) and foam stability (95.2%), respectively. Finally, the determination of the interface adsorption kinetics indicated that the synergy between ovalbumin and lysozyme existed in the dynamic evolution of the interface protein membrane. This research provided the theoretical basis for precise regulation of processing properties in interface-dominated food systems.