The heat stability of milk protein-stabilized oil-in-water emulsions: A review

The knowledge on the factors affecting the heat-induced physicochemical changes of milk proteins and milk protein stabilized oil-in-water emulsions has been advanced for the last decade. Most of the studies have emphasized on the understanding of how milk-protein-stabilized droplets and the non-adsorbed proteins determine the physicochemical and rheological properties of protein-concentrated dairy colloids. The physical stability of concentrated protein-stabilized emulsions (i.e., against creaming or phase separation/gelation after heat treatment) can be modulated by carefully controlling the colloidal properties of the protein-stabilized droplets and the non-adsorbed proteins in the aqueous phase. This article focusses on the review of the physical stability of concentrated milk protein-stabilized oil-in-water emulsions as influenced by physicochemical factors, interparticle interactions (i.e., protein-protein, and droplet-droplet interactions) and processing conditions. Emphasis has been given to the recent advances in the formation, structure and physical stability of oil-in-water emulsions prepared with all types of milk proteins, reviewing in particular the impact of pre- and post-homogenization heat treatments. In addition, the importance of common components found in the continuous phase of heat-treated nutritional emulsions that can promote aggregation (polymers, sugars, minerals) will be highlighted. Finally, the routes of manipulating the steric stabilization of these emulsions to control heat-induced aggregation-through protein-surfactant, protein-protein, protein-polysaccharide interactions and through the incorporation of protein based colloidal particles-are reviewed. (C) 2017 Elsevier Ltd. All rights reserved.