meat, term for the flesh of animals used for food, especially that of cattle, sheep, lambs, and swine, as distinct from game, poultry, and fish; sometimes it is inclusive of all animal flesh. The chief constituents of meat are water, protein, and fat. Phosphorus, iron, and vitamins are also contained in meat, especially in some of the edible organs (e.g., liver). Although meat is digested more slowly than starches or sugars, it has a high food value, with more than 95% of the protein and fat being digested; the fattier meats (e.g., pork) take somewhat longer to digest than the leaner ones. The edible parts of a carcass include lean flesh, fat flesh, and edible glands or organs, such as the heart, liver, kidneys, tongue, tripe, brains, and sweetbread. The comparative toughness of meat depends on the character of the muscle walls and connective tissue, the part of the animal from which the meat is taken, and the age and condition of the animal. Ripening meat, i.e., hanging it for a time at a temperature just above freezing (or, in a more recently developed technique, at a high temperature) permits enzyme action and the formation of lactic acid, which tenderizes it. Good meat may be recognized by a uniform color; a firm, elastic texture; being barely moist to the touch; and having a scarcely perceptible, clean odor. The choicer cuts should be of fine texture and well marbled with fat. Cooking meat not only softens tissues, kills parasites and microorganisms, and coagulates blood and albumen, but makes the meat more palatable by developing its flavors or introducing new ones by means of seasonings and sauces. Meat, where available, has been a staple food since prehistoric times. The meat supply, obtained at first by using the raw flesh of animals found dead, was augmented by trapping; then, as humans developed their tools and a community life, by hunting; and finally, by the domestication of animals. Meat has been subject to prohibitions (see vegetarianism), as well as to butchering regulations on religious and hygienic grounds. Meat consumption has been commonly based on the supply, lamb and mutton being preferred in the Middle East, veal in Italy, and pork and beef in most of Europe and the Americas. The leading producers of meat for export are Argentina, Australia, and New Zealand.