Eggs (uova) are among the most nutritious foods on earth. One large egg contributes approximately 6.5 grams of protein (about 13 percent of the average daily requirement), as well as substantial amounts of thiamin, iron, phosphorous, and vitamins A, D, and E. The yolk contains most of the fat, cholesterol, vitamins, and protein, while the egg white is composed mostly of water and albumen.
Chicken eggs may be the most commonly used in restaurant cooking, but the eggs of several game birds are popular, too. Duck eggs are slightly larger than chicken eggs and contain slightly more fat, which imparts a rich flavor. Goose eggs are significantly larger even than duck eggs, averaging 184 to 200 grams (6½ to 7 ounces). They have a more pronounced flavor than chicken eggs and a very hard, chalky-white shell. Speckled-shell turkey eggs are roughly the same size as duck eggs. Pigeon eggs are small, weighing about 14 grams (½ ounce) each. Tiny, speckled quail eggs are popular for their delicate, creamy texture. Ostrich eggs weigh slightly over 450 grams (1 pound) and have a distinctive flavor, but are often difficult to open.