PHYSICAL-PROPERTIES OF WHEY-PROTEIN STABILIZED EMULSIONS AS RELATED TO PH AND NACL

Corn oil-in-water emulsions (20 wt%, d(32) approximate to 0.6 mu m) st abilized by 2 wt% whey protein isolate were prepared with a range of p H (3-7) and salt concentrations (0-100 mM NaCl), and particle size, rh eology and creaming were measured at 30 degrees C. Appreciable droplet flocculation occurred near the isoelectric point of whey protein (pH 4-6), especially at higher NaCl concentrations. Droplet flocculation i ncreased emulsion viscosity and decreased stability to creaming. Resul ts are related to the influence of environmental conditions on electro static and other interactions between droplets.