Emulsifying capacity

The amount of oil that a given quantity of an emulsifier or emulsifying ingredient can hold in a stable emulsion before the emulsion breaks. A practical functional measure used to compare proteins, lecithins and other surface-active ingredients when formulating dressings, sausages, batters and margarines. It is determined by titrating oil into an emulsifier solution under standardised shear until phase inversion or breakage occurs, and results are expressed as millilitres of oil per gram of emulsifier. Capacity falls as pH approaches the protein’s isoelectric point or as salt screens electrostatic repulsion — practical constraints in sausage and dressing formulation.