CHAPTER II. MEAT: ITS COMPOSITION.
9. Meat, or the flesh of animals used for food, consists of several very distinct substances, each of which possesses different qualities. Some of these substances are hardened, others softened by heat; some dissolved, and others rendered tough by boiling water. It is therefore necessary to understand the nature of these different substances, in order to perform the different operations of cooking in the best and most economical manner.
10. If we take some small shreds of lean meat and wash them repeatedly in clean water, rubbing them at the same time, we shall wash away all the soluble part, and at last there will remain nothing but some white threads which constitute the fibrous part of the flesh of the animal from which they were obtained. We could in this manner obtain about fifteen pounds from every hundred pounds of flesh. This substance of which these threads are composed is termed fibrin; it is an albumenoid (6) article of food. Fibrin also exists dissolved in the blood of
living animals; and when the fresh blood of a pig or other animal is stirred, as is done in making black puddings, the fibrin separates and adheres to the stick in long fibres.
The action of heat on fibrin is very important. It is hardened and contracted by a heat as great as that of boiling water: this is easily shown by pouring some perfectly boiling water on the threads obtained by washing meat, or by cutting a thin shred of meat in the direction of the fibres, boiling it for a few minutes, and then noticing the alteration in its size and the hardening it has undergone.
In water that is considerably less hot than boiling, the fibres of meat become soft, consequently any meat, even if old and tough, can be rendered useful for food by long continued stewing, at a heat much less than that of boiling water.
11. When meat is thoroughly washed to obtain the fibrin, a soluble substance, similar to the white of egg, passes away in the water; this is termed albumen. There are from three to five pounds of albumen in every hundred of meat; it also forms a very large proportion of the brain and of the blood. In cold or warm water it is easily dissolved, but if heated to near the boiling point of water it becomes solid. If a piece of fresh meat is suddenly plunged for a few minutes into water quite boiling, the albumen at the outside is hardened and becoming solid prevents the escape of the juices which form the gravy. Exposed to a heat greater than that of boiling water albumen becomes very horny and indigestible, but when properly cooked it is one of the most valuable articles of diet.
12. The tendinous or gristly parts of the flesh, such as cow's heel, the sinewy parts about the joints, also the skin and the nutritive parts of the bones, consist chiefly of a peculiar substance termed gelatin. This is a valuable albumenoid article of food when used with other substances. Gelatin and gelatinous articles of food may be dissolved by boiling, and the solution becomes a jelly when cold. Gelatin is rendered hard and horny by a dry heat, and therefore the sinewy and tendinous parts of meat are better adapted for stewing or boiling, than for roasting, broiling, or frying.
13. If a quantity of lean meat be chopped up small, and placed in a closely-covered earthen pot, without water, and the pot be then put in a saucepan of water by the side of the fire so as to be very gradually heated, the juice of the flesh will escape. At first this will be of a red colour, being tinged with a little blood, but if heated to a greater degree it will become brown. The juice of the flesh contains many substances of the greatest value as food, and meat from which it is extracted is of very inferior value.
All operations of cookery should be conducted so as to prevent as far as possible any loss of this valuable fluid. When meat is salted a large proportion of the juice of the flesh is extracted and forms the brine. This contains so much albumen as to become partly solid if heated. It is from the loss of this valuable juice that salted meats are so much less nutritious and wholesome than those that are used in a fresh state. What is termed extract of meat is merely the juice of the flesh from which the water has been evaporated so that it is nearly solid.
14. Almost all flesh used for food contains a considerable proportion of fat, which when eaten maintains the warmth of the body. Hence we have a much greater appetite for fat in cold seasons and climates than in those that are warm. Fat is one of the oleaginous foods (7) which are the source of the force we exert; it is also essential to the proper action of the digestive organs. When taken in too great a quantity it accumulates in the body, which thus becomes fattened.
15. The quantity and quality of these different substances vary very much in the different kinds of meat. The flesh of very young animals is not nearly so nutritious as that of those which are of mature age. Lamb and veal contain much less solid food than mutton or beef, and are consequently not so economical, even if purchased at the same cost per pound. Mutton, if in good condition, is one of the most easily digested of the ordinary flesh meats. Pork is not so easily digested as beef or mutton, consequently is unfitted for sick persons, and from the unwholesome manner in which pigs are often kept, is more subject to be diseased than the flesh of sheep or oxen.
16. Some of the internal parts of animals are exceedingly useful as food. The stomach of the ox when cleaned and partially boiled is sold as tripe, an easily digestible and nutritious food. In the tongue the fibres of the flesh are very small and delicate; and if stewed slowly, become very soft and digestible; but tongues are frequently much hardened by salting for a long time. The flesh of the heart of the ox and of the sheep is very firm and solid, and though nutritious, is not very easily digested. Kidney and liver,