Comparison of gum arabic, modified starch, and whey protein isolate as emulsifiers:: Influence of pH, CaCl2 and temperature

The particle size and zeta potential of model beverage emulsions (0.01 wt% soybean oil-in-water emulsions, d approximate to 1 mm) stabilized by gum arabic, modified starch, or whey protein isolate (WPI) were studied with varying pH (3 to 9), CaCl2 concentration (0 to 25 mM), and temperature (30degreesC to 90degreesC). Temperature, pH, CaCl2 strongly influenced emulsions stabilized by WPI because its stabilizing mechanism was mainly electrostatic repulsion, but not those stabilized by gum arabic or modified starch because their stabilizing modes of action were mainly steric repulsion. This study may have important implications for the application of WPI as an emulsifier in beverage emulsions.