Influence of xanthan and CMC mixture on the stability of sodium caseinate emulsions

The influences of the ratio of xanthan gum(XG) to sodium carboxymethyl cellulose(CMC) mixture and the pH on the behavior of oil-in-water caseinate emulsion were investigated.Zeta-potential,droplet size,viscosity,creaming behavior and the microstructure of the emulsion were detected to reveal the possible mechanisms of the stability or instability of the emulsion.Results show that,under neutral condition,both anionic polysaccharides were not absorbed to the surface of the caseinate-coated droplet,which caused the depletion flocculation.The creaming behavior of visual separation was quickly observed during the storage time.Under acid condition,xanthan gum or sodium carboxymethyl cellulose was absorbed to the droplet surface and increased both the electrostatic and steric repulsion of the emulsion.At certain polysaccharide concentrations(CMC∶XG = 1∶1,3∶1,the total addition amount of the emulsion is 0.4 wt%),the stability of the emulsion was enhanced,and during two weeks room temperature storage there was no notable creaming phenomenon.