The interaction of sodium caseinate with monoglyceride and diglyceride at the oil-water interface in corn oil-in-water emulsions and its effect on emulsion stability

The slow rate of drop coalescence at 5 C in concentrated corn oil-in-water emulsions stabilised with sodium caseinate, glyceryl monostearate and glyceryl distearate was deduced from changes in the drop size distribution. Both pH and the monoglyceride/diglyceride ratio influenced coalescence. At any pH minimum coalescence was observed at a 5/2 monoglyceride/diglyceride ratio. This was attributed to association of caseinate with a previously formed complex of monoglyceride and diglyceride, so supporting an interpretation previously proposed on the basis of rheological data for the emulsions and for films of caseinate-glycerides at the oil-water interface.