Emulsifying Properties of Food Proteins: Bovine Serum Albumin

Emulsifying activity (EA) of bovine serum albumin (BSA), at concentrations of 0.07 to 0.45 mM, was maximum at oil:water ratios (o:w) <2:8, in the pH range 4 to 8. At pH 8, the EA was greater than that at pH values below, i.e., < pH 7, but the energy required to form emulsions was higher., EA and emulsion stability (ES) were directly related and improved in NaCl; ES was maximum at pH 4. Surface load was directly related to the o:w and the increase in viscosity with protein load apparently reflected protein unfolding that was marked at an energy input of 680 10 6 J m ‐3 . Data indicate that some native structure and flexibility of the BSA molecule are required for optimum emulsifying properties.