Bird eggs are a common food and one of the most versatile ingredients used in cooking. They are important in many branches of the modern food industry.The most commonly used bird eggs are those from the chicken. Duck and goose eggs, and smaller eggs such as quail eggs are occasionally used as a gourmet ingredient, as are the largest bird eggs, from ostriches. Gull eggs are considered a delicacy in England,as well as in Scandinavian countries, particularly in Norway. In some African countries, guineafowl eggs are commonly seen in marketplaces, especially in the spring of each year. Pheasant eggs and emu eggs are perfectly edible but less widely available.Sometimes they are obtainable from farmers, poulterers, or luxury grocery stores. Most wild bird's eggs are protected by laws in many countries, which prohibit collecting or selling them, or only permit these during specific periods of the year.
Most commercially produced chicken eggs intended for human consumption are unfertilized, since the laying hens are kept without roosters. Fertile eggs can be purchased and eaten as well, with little nutritional difference. Fertile eggs will not contain a developed embryo, as refrigeration prohibits cellular growth for an extended amount of time.
Chicken eggs are widely used in many types of dishes, both sweet and savory. Eggs can be pickled, hard-boiled, scrambled, fried and refrigerated. They can also be eaten raw, though this is not recommended for people who may be especially susceptible to salmonella, such as the elderly, the infirm, or pregnant women. In addition, the protein in raw eggs is only 51% bio-available, whereas that of a cooked egg is nearer 91% bio-available, meaning the protein of cooked eggs is nearly twice as absorbable as the protein from raw eggs. As an ingredient egg yolks are important emulsifier in the kitchen, and the proteins in eggs white makes all kinds of foams and aerated dishes possible.
Quail eggs are considered a delicacy in many countries. They are used raw or cooked as tamago in sushi. In Colombia, quail eggs are considered less exotic than in other countries, and a single hard-boiled quail egg is a common topping on hot dogs and hamburgers, often fixed into place with a toothpick.
A boiled egg can be distinguished from a raw egg without breaking the shell by spinning it. A hard-boiled egg's contents are solid due to the denaturation of the protein, allowing it to spin freely, while viscous dissipation in the liquid contents of a raw egg causes it to stop spinning within approximately three rotations.
The albumen, or egg white contains protein but little or no fat. It is used in cooking separately from the yolk, and can be aerated or whipped to a light, fluffy consistency. The albumen is the healthiest bit of the egg. Beaten egg whites are used in desserts such as meringues and mousse. Ground egg shells are sometimes used as a food additive to deliver calcium. Boiled eggs that are difficult to peel are usually too fresh. Fresh eggs have a lower pH, and this does not allow the shell to separate easily from the underlying albumen. When put into vinegar the shell will dissolve slowly. |