Suppression of depletion flocculation in oil-water emulsions: a kinetic effect of ß-lactoglobulin

This paper reports on creaming and flocculation in 10% (w/w) oil-in-water emulsions, stabilised by -lactoglobulin (-lg) and flocculated by dextran. Dextran and an additional amount of -lg were added at various concentrations after emulsion formation. A substantial effect of the -lg concentration was observed. At higher -lg concentrations, a larger dextran concentration was required to induce network formation. This effect was explained by a retardation of the flocculation process at larger -lg concentrations, shown by diffusing wave spectroscopy (DWS). This retardation was caused by the unexpectedly high apparent viscosity at low shear-rates of mixed solutions of -lg and dextran