A Review of the Application and Antifreeze Mechanism of γ-Polyglutamic Acid in Frozen Foods

Foods are subject to deterioration caused by ice crystal formation and recrystallization during storage and transportation. At present, adding antifreeze is an effective means to delay the deterioration of frozen foods and maintain food quality. γ-Polyglutamic acid (γ-PGA) is an anionic polypeptide polymer whose molecular chain contains a large number of carboxyl groups connecting water molecules through hydrogen bonds, which can reduce water migration, inhibit the growth of ice crystals, and thus has excellent antifreeze effect. Additionally, γ-PGA has the advantages of low salt, low calorie, and promoting mineral absorption, and can better meet consumer demands for reduced sugar, reduced fat, reduced salt foods than traditional commercial antifreeze. Based on the current status of γ-PGA research, this paper reviews the basic structure and antifreeze mechanism of γ-PGA and its application in the food industry in order to provide a theoretical reference for the development and application of food-grade γ-PGA antifreeze in the food field.