Abstract: Bilayer emulsion is a multilayer emulsion, and it is generally prepared by layer-by-layer self-assembly technique. Bilayer emulsion forms double interface layers that consist of some biopolymers (such as proteins and polysaccharides) or phospholipids and small molecular surfactants (Tween) via electrostatic adsorption or covalent bond on the surface of emulsion droplets. Compared with the traditional single layer emulsion, bilayer emulsion has more advantages in stability, resistance to environmental stresses (such as pH, temperature, and ionic strength) and the ability to protect encapsulated bioactive substances and control their release for use as a delivery system. Because of its unique advantages, bilayer emulsion has broad prospects for application in the food industry and functional foods. The present article reviews the preparation, interface layer components and stability of bilayer emulsions. The advantages and applications of bilayer emulsions in food industry are also presented.

Key words: bilayer emulsion, proteins, polysaccharides, electrostatic adsorption, covalent bonds, delivery systems