Abstract: Egg yolk is an important food ingredient because of its outstanding nutritional value and emulsifying properties. The insoluble particle structure present in egg yolk and heat treatment during food processing may lead to poor stability of egg yolk emulsion. Hydrolysis, as a safe, efficient and low-energy modification method, has been widely used in studies on improving the emulsifying properties of egg yolk. In this paper, the effects of hydrolysis on the molecular structure, physicochemical properties and emulsifying characteristics of egg yolk are reviewed. Taking into account the actual needs of production, the formation mechanism and removal process of off-flavor in egg yolk hydrolysis products are discussed. Finally, this review summarizes the application of the emulsifying properties of egg yolk in the field of food processing, with a view to providing theoretical references for research on the hydrolytic modification of egg yolk.

Key words: egg yolk; protein; limited enzyme hydrolysis; emulsifying properties; off-flavor