earticle

영어

The stability of corn oil-in-water emulsions coated by milk proteins, sodium caseinate (CAS), or whey proteinconcentrate (WPC), was compared under the environmental stress of pH change. Emulsions were prepared at 0.1 of protein:oilbecause the majority of droplets were relatively small (d32=0.34 and 0.35µm, d43=0.65 and 0.37µm for CAS- and WPC-emulsions, respectively) and there was no evidence of depletion flocculation. As the pH of the emulsions was graduallydropped from 7 to 3, there was no significant difference in the electrical charges of the emulsion droplets between the 2 typesof emulsions. However, laser diffraction measurements, microscopy measurements, and creaming stability test indicated thatWPC-emulsions were more stable to droplet aggregation than CAS-emulsions under the same circumstance of pH change. Itimplies that factors other than electrostatic repulsion should contribute to the different magnitude of response to pH change.