Egg

(Chicken) Eggs are oval shaped bodys laid by hens, naturally for reproduction of offspring. Eggs are used as food for their high protein value. They are sold unfertilized in most cases, and different recipes of post-processing exist; most eggs are cooked before eating.

An egg consists mainly of a protective eggshell, the albumen (egg white) and the yellow or orange egg yolk.

Eggs are mostly carried in egg cartons, in numbers of 6, 10 or 12.

Egg Size Scales
There are different scales for grading egg sizes, Chicken eggs are graded by size, for the purpose of sales. The United States Department of Agriculture sizing is based by weight per dozen. The most common US size of chicken egg is 'Large' and is the egg size commonly referred to for recipes. The following egg masses have been calculated on the basis of the USDA sizing:

In Europe, modern egg sizes are defined as follows:

In Australia, the Australian Egg Corporation defines the following sizes in its labelling guide.

In Western Australia, two additional sizes are also standardized by the Golden Eggs Corporation

In New Zealand sizes are based on the minimum mass per egg:

History
Bird eggs have been valuable foodstuff since prehistory, in both hunting societies and more recent cultures where birds were domesticated. In Thebes, Egypt, the tomb of Haremhab, built about 1420 BCE, shows a depiction of a man carrying bowls of ostrich eggs and other large eggs, presumably those of the pelican, as offerings.[11] In ancient Rome, eggs were preserved using a number of methods, and meals often started with an egg course.[11] The Romans crushed the shell in their plate to prevent evil spirits from hiding there.[1] In the Middle Ages, eggs were forbidden during Lent because of their richness.[1] It is possible that the word mayonnaise was derived from moyeu, the medieval French word for the yolk meaning center or hub.[1]

Egg scrambled with acidic fruit juices were popular in France in the 17th century; this may have been the origin of lemon curd.[6]

The dried egg industry developed in the 19th century, before the rise of the frozen egg industry.[12] In 1878, a company in St. Louis, Missouri started to transform egg yolk and white into a light-brown, meal-like substance by using a drying process.[12] The production of dried eggs significantly expanded during World War II, for use by the United States Armed Forces and its allies.[12]