Effect of sugar on the rheological properties of sunflower oil–water emulsions Original Research Article

The rheological properties of sunflower oil–water emulsions were studied at constant oil (79%), with varying sugar concentrations (0.0–8.0%) and different temperatures (25–65°C). Sugar improved the emulsion stability. The empirical power law fitted the apparent viscosity-rotational speed data. All emulsions exhibited pseudoplastic behaviour. An average flow behaviour index of 0.49±0.03 was proposed as power law index for all emulsions. The consistency index was influenced by the sugar content and temperature. This dependency was described by an exponential equation. The effect of temperature on consistency of emulsions followed an Arrhenius type equation. Depending on the sugar content, the activation energy values varied from 31077 to 10716 kJ/kg mol.