Protein interactions and filler effects in heat-set gels based on egg

The effect of incorporation of emulsified oil with yolk on the strength of gel network systems, produced by heating of egg yolk or egg white dispersions, was investigated. The yolk gels exhibited a decrease in their mechanical strength as a result of oil incorporation. The white-based gels, on the other hand, showed a higher strength, following incorporation of oil droplets, the result depending on the droplet size but more on oil levels. The interaction between the globular proteins of egg white and the lipoprotein-covered oil droplet surfaces was established by applying SDS-PAGE electrophoresis. The results are discussed in terms of the differences in structure between the yolk and the white proteins that may affect the way they denature and interact following heating.