A novel oleogel based on porous microgel from egg white

In this study, oleogel was prepared by oil absorption using egg white microgel (EWM), and the EWM was obtained through microwave hydrothermal treatment, freeze-thawing, ethanol solvent replacement, atmospheric drying and ball milling pulverization. Compared with water bath and hydrothermal method, microwave hydrothermal treatment had higher heating efficiency to form egg white hydrogel (EWH). Ethanol solvent exchange reduced the surface tension from water evaporation, allowing the porous structure of EWH to be maintained during atmospheric pressure drying, while EWH structure collapsed without solvent exchange. Ball milling made EWM present smaller particle size and higher specific surface area than common pulverization, owing excellent oil holding ability (1.24 ± 0.04 g/g) and great ability to form networks in oil. Compared to control oleogel based on microgel without solvent exchange or by common pulverization, EWM oleogel showed higher viscosity and gelatinability, which was beneficial to the improvement of oxidation stability. This oleogel can be further used as the solid fat alternative or bioactive substance delivery carriers in food industry.