Comparison of the effects of three different phosphatidylcholines on casein-stabilized oil-in-water emulsions
- 134 Downloads
Soy oil-in-water emulsions, stabilized by casein, but incorporating one of three different phosphatidylcholines (PC), namely egg-PC, di-palmitoyl phosphatidylcholine (DPPC) and di-oleyl phosphatidylcholine (DOPC), have been studied by photon correlation spectroscopy, light scattering, fast protein liquid chromatography, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Egg-PC enhanced the stability of emulsions made with low casein concentration, and it competed for space with casein at the oil-water interface during the emulsification process, but no further displacement of protein was found. DPPC had little effect on emulsion stability nor did it show a detectable competition at the interface with casein during or after emulsification. DOPC, however, not only competed with casein at the interface during emulsification, it also removed casein from the interface during storage of the emulsion. The displacement of casein caused instability of the emulsions. Adding DOPC to emulsions also led to displacement of casein from the interface and caused instability of the emulsion, but the process was much slower and occurred to a smaller extent compared to emulsions prepared with DOPC. The different behavior of egg-PC, DPPC, and DOPC on the oil-water interface was in good agreement with their relative solubility in the oil phase as measured by spectrophotometry. All three lipids modified the hydrodynamic thickness of the adsorbed casein layer corresponding to their modification of the surface concentration of casein.
Key WordsCasein lecithin lipid protein interaction oil-water interface
Unable to display preview. Download preview PDF.
- 1.Graf, T., and L. Meyer, Use of Lecithin in Food,Int. Flavours Food Additives 7:218–221 (1976).Google Scholar
- 2.Szuhaj, B.F., and G.R. List,Lecithins, American Oil Chemists' Society, Champaign, 1985.Google Scholar
- 4.Dickinson, E., and G. Iveson, Adsorbed Films of β-Lactoglobulin + Lecithin at the Hydrocarbon-Water and Triglyceride-Water Interface,Food Hydrocoll. 6:533–541 (1993).Google Scholar
- 5.Bergenstahl, B.A., and P.M. Claesson, Surface Forces in Emulsions, inFood Emulsions, 2nd edn., edited by K. Larsson and S.E. Friberg, Dekker, New York, 1990, pp. 41–96.Google Scholar
- 7.Muir, D.D., and A.W.M. Sweetsur, Production and Properties of In-Can Sterilised Concentrated Milk with 39% Solids: Process Optimisation,Milchwissenshaft 47:80–83 (1992).Google Scholar
- 8.Hardy-Lloyd, E.E., A.W.M. Sweetsur, I.G. West, and D.D. Muir, Preparation and Properties of Sterilized Concentrated Milk Incorporating Lecithin,Milchwissenshaft 41:470–473 (1986).Google Scholar
- 9.De Feijter, J.A., J. Benjamins, and M. Tamboer, Adsorption Displacement of Proteins by Surfactants in Oil-in-Water Emulsions,Colloids Surf. 27:243–266 (1987).Google Scholar
- 13.Heertje, I., J. Nederlof, H.A.C.M. Hendrickx, and E.H. Lucassen-Reynders, The Observation of the Displacement of Emulsifiers by Confocal Scanning Laser Microscopy,Food Structure 9:305–316 (1990).Google Scholar
- 18.Dickinson, E., and V. Galazka, Emulsion Stabilization by Ionic and Covalent Complexes of β-Lactoglobulin with Polysaccharides,Food Hydrocoll. 5:281–296 (1991).Google Scholar
- 19.Johansson, D., and B. Bergenstahl, Lecithins in Oil-Continuous Emulsions. Fat Crystal Wetting and Interfacial Tension,J. Am. Oil Chem. Soc. 72:205–211 (1995)Google Scholar
- 24.Chen, J.S., E. Dickinson, and G. Iveson, Interfacial Interactions, Competitive Adsorption and Emulsion Stability,Food Structure 12:135–146 (1993).Google Scholar