Foaming and structural properties of egg yolk components microgel particles and their adsorption characteristics at the air-water interface

In this study, microgel particles of egg yolk and its components were constructed by inducing and modifying their structure via the high-pressure homogenization (HPH). In order to compare their structural characterization and reveal their adsorption mechanism at the air-water interface, yolk components were also combined with egg white protein (EWP) to achieve their microgels for investigation. Results suggested that after HPH, foam stabilities of egg yolk protein microgel (EYM) and egg yolk plasma microgel (EPM) were significantly improved, whereas no significance occurred on egg yolk granules microgel (EGM). Interestingly, after HPH, the adsorption capacity of the microgels from combination of yolk components and EWP exhibited a significant increasing trend. However, their interfacial adsorption stability was poor. Fluorescence spectrum and surface tension revealed that more hydrophilic groups and lower surface tension would occur on EY and EP after HPH, whilst no significant effects would happen on EG, which was consistent with the results of foaming characteristics. SDS-PAGE exhibited that there was no obvious change in the protein bands of egg yolk and its components, indicating that egg yolk and component proteins did not undergo covalent crosslinking or degradation with HPH treatment. In summary, our study prepares for the first time of the microgel particles from egg yolk components for stabilizing the air-water interface. In addition, we have revealed the relationship between the physicochemical properties, microstructures and interfacial adsorption properties of the microgel particles from egg yolk components, and have explored their mechanisms in depth.