Structure formation in casein-based gels, foams, and emulsions

The exceptional surface-active and stabilizing properties of casein have been recognized from the earliest days of colloid science, and casein has long been employed as a functional ingredient in food processing. With its unique physico-chemical properties, this natural polymeric surfactant has potential for even greater use in formulation science and nanoscale processing technology. Gels may be produced from solutions of sodium caseinate, from micellar casein dispersions, and from casein-stabilized emulsions by a variety of treatments, including heating, acidification, and high-pressure processing. The temperature dependence of the interactions and the state of aggregation can be controlled by systematically varying the ionic composition of the system. By incorporating air bubbles into gradually flocculating caseinate-stabilized emulsions via simultaneous whipping and slow acidification, aerated emulsion gels of good foam stability can be formulated.