CARBOHYDRATE IN MEAT.--In the liver and all muscle fibers of animals is stored a small supply of carbohydrate in a form that is called glycogen, or muscle sugar. However, there is not enough of this substance to be of any appreciable value, and, so far as the methods of cookery and the uses of meat as food are concerned, it is of no importance.

WATER IN MEAT.--The proportion of water in meat varies from one-third to three-fourths of the whole, depending on the amount of fat the meat contains and the age of the animal. This water carries with it the flavor, much of the mineral matter, and some food material, so that when the water is removed from the tissues these things are to a great extent lost. The methods of cookery applied to meat are based on the principle of either retaining or extracting the water that it contains. The meat in which water is retained is more easily chewed and swallowed than that which is dry. However, the water contained in flesh has no greater value as food than other water. Therefore, as will be seen in Fig. 1, the greater the amount of water in a given weight of food, the less is its nutritive value.

MINERALS IN MEAT.--Eight or more kinds of minerals in sufficient quantities to be of importance in the diet are to be found in meat. Lean meat contains the most minerals; they decrease in proportion as the amount of fat increases. These salts assist in the building of hard tissues and have a decided effect on the blood. They are lost from the tissues of meat by certain methods of cookery, but as they are in solution in the water in which the meat is cooked, they need not be lost to the diet if use is made of this water for soups, sauces, and gravies.

EXTRACTIVES IN MEAT.--The appetizing flavor of meat is due to substances called extractives. The typical flavor that serves to distinguish pork from beef or mutton is due to the difference in the extractives. Although necessary for flavoring, these have no nutritive value; in fact, the body throws them off as waste material when they are taken with the food. In some methods of cookery, such as broiling and roasting, the extractives are retained, while in others, such as those employed for making stews and soups, they are drawn out.

Extractives occur in the greatest quantity in the muscles that the animal exercises a great deal and that in reality have become tough. Likewise, a certain part of an old animal contains more extractives than the same part of a young one. For these reasons a very young chicken is broiled while an old one is used for stew, and ribs of beef are roasted while the shins are used for soup.

Meat that is allowed to hang and ripen develops compounds that are similar to extractives and that impart additional flavor. A ripened steak is usually preferred to one cut from an animal that has been killed only a short time. However, as the ripening is in reality a decomposition process, the meat is said to become "high" if it is allowed to hang too long.