Abstract
Protein-stabilised emulsions are one example of oil-in-water emulsions. Many proteins are surface active molecules that can adsorb at the oil-water interface to facilitate the formation of an emulsion. The adsorbed proteins form a protective layer surrounding the oil droplets, which provide stability to the emulsion. Due to the biphasic nature of the emulsion, separation of oil and water phases is common during long-term storage. The emulsions can undergo destabilisation mechanisms such as flocculation, creaming, sedimentation and coalescence. Extensive studies have been carried out to understand the destabilisation mechanisms and the factors affecting emulsion stability. Processing parameters (homogenisation and heat treatment), emulsion conditions (pH and ionic strength) and formulation with biopolymers and emulsifiers have been identified as critical factors affecting emulsion stability. Water-soluble and oil-soluble emulsifiers also interact differently with proteins at the interface, thus affecting the physicochemical properties and stability of an emulsion. Studies on the complex interaction between biopolymers and emulsifiers will advance our understanding on stability and shelf life of food emulsions.