DISPERSION STATE OF PROTEIN-STABILIZED EMULSIONS

The stability of concentrated benzene-in-water emulsions emulsified by bovine serum albumin (BSA) in the presence of various concentrations of sodium chloride has been measured in the light of the coalescence kinetics. On the acid and alkaline sides of the isoelectric point of BSA (pH 4.9), the rate of coalescence between globules decreased and approached that at the isoelectric point of BSA with increasing concentrations of sodium chloride. In these systems, the interfacial tension at the benzene/aqueous BSA solution interface, and the globule size distribution in the emulsions, reached the values observed at the isoelectric point when the concentration of sodium chloride was above about 50 mM. The role of the adsorbed film of BSA on the surface of dispersed globules is considered in relation to the dissociation state of the BSA molecules.