Bird eggs are a common food source. The most commonly used bird eggs are those from the chicken, duck, and goose, but smaller eggs such as quail eggs are occasionally used as a gourmet ingredient, as are the largest bird eggs, from ostriches. Most commercially produced chicken eggs intended for human consumption are unfertilized, since the laying hens are kept without any 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.
Chicken eggs are widely used in many types of cooking. Dishes that use eggs range from both sweet to savoury dishes. Eggs may be pickled; hard-boiled, scrambled, fried and refrigerated; or eaten raw, though the latter is not recommended for people who may be susceptible to salmonella, such as the elderly, the infirm, or pregnant women. In addition, the protein in raw eggs are only 51% bio-available, whereas 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.[1]
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 the inertia of the liquid contents of a raw egg causes it to stop spinning within approximately three rotations.
