INFLUENCE OF OIL AND EMULSIFIER CONCENTRA TIONS ON THE RHEOLOGICAL PROPERTIES OF OIL-IN-WATER SALAD DRESSING FOOD EMULSIONS

The viscous and viscoelastic behaviour of food emulsions containing a mixture of egg yolk and sucrose stearate as a function of oil and sucr ose stearate concentrations were studied. Oil concentrations ranged be tween 40-55% w/w for emulsions containing 5% w/w sucrose stearate and sucrose ester concentrations varied between 0-10% w/w for emulsions co ntaining 50% w/w oil. Steady flow, linear oscillatory shear tests and droplet size distribution measurements were carried out. An increase i n oil or emulsifier concentration produced an increase in both the ste ady-state viscosity and in the viscoelastic functions. The results hav e been explained on the basis of the relationship between the structur al parameters and the theology of the emulsions studied.