Interactions and competitive adsorption effects in egg-based products

Abstract

Differences in structure between egg constituent proteins influence their ability to interact, upon heating, in gel systems or to compete for space at the interface of oil droplets in oil/water (o/w) emulsions. Phase separation phenomena could be the rule in protein network systems where mixtures of egg yolk with egg white or other protein containing materials are employed. In emulsions, apolipoproteins of LDL micelles appear to play a dominant role in adsorption and interfacial membrane formation around the oil droplets. Yolk granular proteins also have the ability to contribute in the building of the adsorbed layer although their adsorption and stabilizing potential seem to depend on factors as such as NaCl content and pH and also on the extent of granular structure disorganization. Egg white and milk whey proteins are competitively displaced from emulsion oil interfaces by yolk lipoproteins due to the globular and rigid structure of the former. Casein proteins also appear to adsorb less effectively in the presence of yolk apolipoproteins in spite of their rather disorganized molecular structure.