Varieties of Meat.
BEEF TONGUE.
Beef tongue is a tender form of meat, but contains too much fat to agree well with people of delicate digestion.
VEAL.
Veal, when obtained from animals killed too young, is apt to be tough, pale and indigestible, but good veal is considered fairly nutritious.
It contains more gelatin than beef, and in broth is considered valuable, especially for the sick.
MUTTON.
Mutton is considered to be more digestible than beef, that is well fed mutton from sheep at least three years old; but as it is more difficult to obtain tender mutton than beef, the latter is more generally preferred. Mutton broth is wholesome and valuable in sickness.
LAMB.
Lamb, when tender and of the right age, is quite as digestible as beef or mutton, but the flesh contains too large a proportion of fat.
[Ill.u.s.tration: FIG. 1.--Diagram of cuts of beef.]
[Ill.u.s.tration: FIG. 2.--Diagram of cuts of veal.]
[Ill.u.s.tration: FIG. 3.--Diagram of cuts of pork.]
[Ill.u.s.tration: FIG. 4.--Diagram of cuts of mutton.]
VENISON.
Venison is a tender meat with short fibres, which is very digestible when obtained from young deer, but is considered to be rather too stimulating. Its chemical composition is similar to lean beef.
PORK.
Pork is a tender-fibred meat, but is very indigestible owing to the high percentage of fat, which is considerably more than the nitrogenous material it contains. Pork ribs may have as much as 42 per cent. of fat.
HAM AND BACON.
Ham is more digestible when well boiled and eaten cold. Bacon is more easily digested than either ham or pork; when cut thin and cooked quickly--until transparent and crisp--it can often be eaten by dyspeptics, and forms an excellent food for consumptives.
FOWL.
Chicken is one of the most digestible of meats, contains considerable phosphorus and is particularly valuable as food for invalids. Turkey is somewhat less digestible than chicken. Ducks and geese are difficult of digestion, unless quite young, on account of the fat they contain.
GAME.
Game, if well cooked, is fairly digestible.
SWEETBREAD.
Sweetbread, which is thymus gland of the calf, is a delicate and agreeable article of diet, particularly for invalids. Tripe, heart, liver and kidneys are other forms of animal viscera used as food--valuable chiefly as affording variety.
FISH.
The chief difference in fish is the coa.r.s.eness of fibre and the quant.i.ty of fat present. Fish which are highly flavored and fat, while they may be nutritious, are much less easy of digestion than flounder, sole, whitefish, and the lighter varieties. The following fish contain the largest percentage of alb.u.minoids:--Red snapper, whitefish, brook trout, salmon, bluefish, shad, eels, mackerel, halibut, haddock, lake trout, ba.s.s, cod and flounder. The old theory that fish const.i.tuted "brain food," on account of the phosphorus it contained, has proved to be entirely without foundation, as in reality many fish contain less of this element than meat. The tribes which live largely on fish are not noted for intellectuality. Fish having white meat when broiled or boiled--not fried--are excellent food for invalids or people of weak digestion. Fish should be well cooked.
OYSTERS.
Oysters are a nutritious food, and may be eaten either raw or cooked.
Lobsters, crabs and shrimps are called "sea scavengers," and unless absolutely fresh are not a desirable food.
MILK.
Milk contains all the elements which are necessary to maintain life; and const.i.tutes a complete diet for infants. It will sustain life in an adult for several months. Although milk furnishes a useful food, it is not essential to a diet required for active bodily exercise. It is seldom given to athletes while in active training. Adults who are able to eat any kind of food are kept in better health by abstaining from milk, except as used for cooking purposes. An occasional gla.s.s of hot milk taken as a stimulant for tired brain and nerves is sometimes beneficial. Milk is composed of water, salts, fat, milk sugar or lactose, alb.u.men and casein. Average milk has from 8 to 10 per cent.
of cream. Good milk should form a layer of cream about 2-1/2 in. thick as it stands in a quart bottle. Lactose (milk sugar) is an important ingredient in milk. It is less liable to ferment in the stomach than cane sugar. In the presence of fermenting nitrogenous material it is converted into lactic acid, making the milk sour. Casein is present in milk chiefly in its alkaline form, and in conjunction with calcium phosphate. Milk absorbs germs from the air and from unclean vessels very readily. Good, clean, uncontaminated milk ought to keep fresh, exposed in a clean room at a temperature of 68 F., for 48 hours without souring. If the milk is tainted in any way it will sour in a few hours. Boiled milk will keep fresh half as long again as fresh milk. Milk absorbs odors very quickly, therefore should never be left in a refrigerator with stale cheese, ham, vegetables, etc., unless in an air-tight jar. It should never be left exposed in a sick room or near waste pipes. Absolute cleanliness is necessary for the preservation of milk; vessels in which it is to be kept must be thoroughly scalded with boiling water, not merely washed out with warm water.
_Methods of Preserving Milk._
STERILIZED MILK.
Milk to be thoroughly sterilized and germ free must be heated to the boiling point (212 F.). This may be done by putting the milk into perfectly clean bottles and placing in a rack, in a kettle of boiling water, remaining until it reaches the necessary degree of heat. The bottle should be closely covered _immediately_ after with absorbent cotton or cotton batting in order to prevent other germs getting into the milk.
PASTEURIZED MILK.
The difference between pasteurizing and sterilizing is only in the degree of heat to which the milk is subjected. In pasteurizing, the milk is kept at a temperature of 170 F. from 10 to 20 minutes. This is considered a better method for treating milk which is to be given to young children, as it is more easily digested than sterilized milk.
All milk should be sterilized or pasteurized in warm weather, especially for children.
CHEESE.
Cheese is one of the most nutritious of foods, and when meat is scarce makes an excellent subst.i.tute, as it contains more protein than meat.
Cheese is the separated casein of milk, which includes some of the fats and salts.
EGGS.
Eggs contain all the ingredients necessary to support life. Out of an egg the entire structure of the bird--bones, nerves, muscles, viscera, and feathers--is developed. The inner portion of the sh.e.l.l is dissolved to furnish phosphate for the bones. The composition of a hen"s egg is about as follows (Church):--
----------------------+------------++---------------------+------------ | White--In || | Yolk--In | 100 parts. || | 100 parts.
----------------------+------------++---------------------+------------ Water | 84.8 || Water | 51.5 Alb.u.men | 12.0 || Casein and alb.u.men | 15.0 Fat, sugar, | || Oil and fat | 30.0 extractives, etc. | 2.0 || Pigment | Mineral matter | 1.2 || extractives, etc. | 2.1 | || Mineral matter | 1.4 ----------------------+------------++---------------------+------------
The alb.u.men--or the "white"--of an egg is greatly altered by cooking.
When heated beyond boiling point it becomes a very indigestible substance. Eggs cooked at a temperature of about 170 F., leaving the whites soft, are easily digested. A raw egg is ordinarily digested in 1-1/2 hour, while a baked egg requires from 2 to 3 hours. Eggs _baked_ in puddings, or in any other manner, form one of the most insoluble varieties of alb.u.men.
GELATIN.
Gelatin is obtained from bones, ligaments, and other connective tissues. In combinations with other foods it has considerable nutritive value. The place given to it by scientists is to save the alb.u.men of the body; as it does not help to form tissue or repair waste it cannot replace alb.u.men entirely. Gelatin will not sustain life, but when used in the form of soup stock, etc., is considered valuable as a stimulant.