pH Effect on Viscoelastic Behavior and Physiochemical Properties of Walnut Oil Emulsions

Abstract

The influence of pH of walnut oil emulsions on droplet morphology, droplet size distribution, time and temperature stability, and rheological properties has been studied. It has been found that walnut oil based emulsions form a metastable gel-like microstructure at steady conditions revealed by a linear viscoelastic response at low deformations. Flow curves of investigated emulsions demonstrated shear thinning behavior at moderate shear rates with a tendency to a limiting viscosity at higher loads. The most stable emulsion was formed at weakly acidic conditions (pH = 6), which favors the formation of fine uniform droplets with no visible tendency to coagulation at ambient conditions.

Keywords

• emulsion stability
• viscoelasticity
• viscosity
• shear thinning
• ph effect
• droplet morphology