Frozen Egg Yolk Gelation Mechanism and Inhibition Method: A Review

The egg yolk is rich in nutrients and is a widely used ingredient in processed foods owing to its excellent emulsifying properties. Freezing can maximize the preservation of the original flavor of the egg yolk, inhibit microbial growth, minimize quality decline during transportation and storage, and extend its shelf life. However, upon thawing, the fluidity of the frozen yolk decreases, viscosity increases, and gelation occurs. Gelation makes it difficult to mix the yolk with other food ingredients, thereby reducing its dispersibility and functionality. To better understand the phenomenon of frozen yolk gelation, herein, this paper reviews up-to-date research on the mechanisms through which frozen yolk gelation occurs, including the formation of ice crystals, lipoprotein aggregation during freezing, and the influence of environmental factors. Various methods to inhibit frozen yolk gelation are also explored, including physical, chemical, and enzymatic methods. Because different methods inhibit frozen yolk gelation through different mechanisms, understanding the causes of frozen yolk gelation and the mechanisms underlying the methods of its inhibition can provide theoretical bases for improving the useability of frozen yolks in food preparation.