Storing of Eggs in the Refrigerator
Eggs begin to deteriorate as soon as they are laid and lose quality very rapidly at room temperature. To ensure the freshness of whole or liquid eggs, they may be refrigerated, frozen, or dried.
Storing in the Refrigerator
Whole Eggs. Several signs distinguish fresh eggs from those that have aged. Changes in proteins over time cause egg whites to thin. Fresh eggs also have more prominent, viscous chalazae on either side of the yolk than older eggs. In the process of aging, the vitelline membrane weakens and the yolk migrates or breaks. The size of an egg’s air cell provides another indication of its age. The air cell gap between the membranes increases in size as the egg ages because moisture and carbon dioxide escape through the porous shell.
Proper refrigeration of eggs helps to delay these changes and protects them from microbial growth, thus helping to maintain their quality. Many home refrigerators have built-in egg containers, but eggs retain their moisture better and keep longer if stored in the carton. Eggs should sit in the carton with their large ends up to prevent the air cell from moving toward the yolk. Washing eggs is not recommended, because this will remove the oil coating applied by the processor to prevent microbial growth and moisture loss.
Refrigerated whole eggs should stay fresh for about a month. Separated egg yolks may be stored under water in the refrigerator, but should be used within two days. Egg whites kept tightly covered in a glass container will last up to four days.
Storage Eggs. Restaurants, food service institutions, and other food manufacturers must be especially careful about storing eggs, because they purchase such large quantities. Storage eggs, used by commercial food service establishments, are usually used within a month, but can be stored for up to six months. They are not available at the retail level. The coating of oil or plastic prevents microbial invasion and any loss of moisture or carbon dioxide.
Liquid Pasteurized Eggs. Another type of egg product available to commercial outlets is refrigerated liquid eggs that have been pasteurized. Typical processed food products that may incorporate pasteurized liquid egg whites include baked goods, candies, and chilled or frozen desserts. The USDA regulations require that all liquid, frozen, or dried eggs be pasteurized or otherwise treated to protect against Salmonella. After being pasteurized, the advantages of liquid eggs over whole eggs or even frozen egg blends are convenience, consistent quality, microbial safety, and costs savings in terms of space, labor, and freezing.
