Emulsifying Properties of Food Proteins: Development of a Standardized Emulsification Method

A recirculating valve-homogenizer was used to compare the emulsifying properties of bovine serum albumin and milk proteins. The energy input per unit volume was directly obtained from the mean maximum valve head pressure per stroke. The mean maximum velocity of the emulsion in the valve head was 83m sec^?1 during a valve opening time of 150 × 10 ^?3 sec reflecting a large velocity gradient per stroke of 4.2 × 10^?6 m³ The method detected changes in the emulsifying activity of proteins resulting from chemical modification, and from process or environmental factors, e.g., ionic strength. The valve-head pressure profile was used to compare the fluidity of the emulsions at different levels of energy input per unit volume (E) and an apparent viscosity index (AVI) has been proposed.