The interaction of sodium caseinate with monoglyceride and diglyceride at the oil-water interface and its effect on interfacial rheological properties

The viscoelasticity at a corn oil-water interface of films of sodium caseinate, and of sodium caseinate plus glyceryl monostearate (GMS) and glyceryl distearate (GDS), have been examined. Caseinate films exhibited little viscoelasticity, but in the presence of GMS and GDS significant viscoelasticity developed. The magnitude of the viscoelasticity parameters was influenced by the GMS/GDS ratio employed at any caseinate concentration. Optimum values of the parameters were obtained at a 5/2 GMS/GDS ratio. This was attributed to association of caseinate with the glycerides, which had themselves entered into some form of association prior to adsorption of caseinate.