Effect of CaCl 2 and KCl on Physiochemical Properties of Model Nutritional Beverages Based on Whey Protein Stabilized Oil‐in‐Water Emulsions

Calcium chloride (0 to 10 mM) and potassium chloride (0 to 600 mM) were added into model nutritional beverage emulsions containing 7% (w/w) soybean oil droplets and 0.35% (w/w) whey protein isolate (pH 6.7). The particle size, surface charge, viscosity, and creaming stability of the emulsions then were measured. The surface charge decreased with increasing mineral ion concentration. The particle size, viscosity, and creaming instability of the emulsions increased appreciably above critical CaCl 2 (3 mM) and KCl (200 mM) concentrations because of droplet flocculation. The origin of this effect was attributed to reduction of the electrostatic repulsion between droplets due to electrostatic screening and ion binding. CaCl 2 promoted emulsion instability more efficiently than KCl because Ca 2+ ions are more effective at reducing electrostatic repulsion than K + ions.