INFLUENCE OF TRISTEARIN CRYSTALS ON THE APPARENT INTERFACIAL SHEAR VISCOSITY OF AQUEOUS LYSOZYME-HYDROCARBON MODEL SYSTEMS

An automated Couette-type torsion-wire surface shear viscometer was us ed to measure the apparent interfacial shear viscosity of a pH 7 (I = 0.05 M) phosphate-buffered lysozyme solution in contact with n-tetrade cane at a planar interface. When tristearin crystals were present in t he oil phase and lysozyme in the aqueous phase, a higher initial appar ent interfacial shear viscosity resulted than would be expected from t he individual contributions of lysozyme and crystals alone. It is sugg ested that this synergism is due to the adsorption of hydrophobic grou ps of the lysozyme to tristearin crystals at the interface. Interactio ns between proteins and fat crystals are thought to be of significance in the stabilization of many food emulsions. (C) 1994 Academic Press, Inc.