Chapter III: Classification of Foods (1)

In the previous chapters, we have given the classification of the elements in foods (foodstuffs) which supply the body needs. In this chapter the foods commonly used are classified according to the predominance of these elements.

_CARBONACEOUS FOODS_

While all foods contain a combination of elements, some contain a greater proportion of carbohydrates and fats, and are classed as _carbonaceous_.

* * * * *

[Sidenote: Roots and Tubers]

Of the carbohydrates, next in importance to the sugars and to the starches in their purest form (cornstarch, tapioca, sago, and arrowroot), come the roots and tubers, such as potatoes, sweet potatoes, beets, parsnips, turnips, and onions.

The following table shows the proportion of various foodstuffs in these vegetables. The skins of the vegetables are included.

TABLE I

ROOTS AND TUBERS

——————————————+—————————+—————————+—————————+—————————+—————+——————————
| Water | Protein | Fat |Carbo- | Ash |Food Value
FOOD MATERIALS|per cent.|per cent.|per cent. hydrates |per |per pound
| | | |per cent.|cent.| Calories
——————————————+—————————+—————————+—————————+—————————+—————+——————————
Sweet Potatoes| 69.4 | 1.5 | 0.3 | 26.2 | 2.6 | 440
White Potatoes| 75.0 | 2.1 | 0.2 | 22.0 | 0.7 | 295
Parsnips | 64.4 | 1.3 | 0.4 | 10.8 | 1.1 | 230
Onions | 86.0 | 1.9 | 0.1 | 11.3 | 0.7 | 225
Beets | 87.0 | 1.4 | 0.1 | 7.3 | 0.7 | 160
Carrots | 88.2 | 1.1 | 0.4 | 8.2 | 6.0 | 210
Turnips | 92.7 | 0.9 | 0.1 | 0.1 | 0.6 | 120
——————————————+—————————+—————————+—————————+—————————+—————+——————————

_Potatoes._ It will be noted from the table given above that sweet potatoes contain a larger percentage of carbohydrates, hence they produce more heat and energy than any other vegetable; next to the sweet potato comes the Irish or white potato.

While the white potato contains two per cent. of protein, this is almost all located in a very thin layer immediately beneath the skin, so that when the potato is peeled in the ordinary way, the protein is removed. This is true of many vegetables. They lose their distinctive flavor, as well as their value as tissue-building foods, when the skins are removed, especially before cooking. Many vegetables may be peeled after being cooked and their value in nutrition is thus increased. All tubers gain in dietetic value if they are cooked in their skins, the thin outer covering being removed after the cooking process is completed. The ordinary cook, however, is unwilling to take the trouble to prepare them in this way.

In vegetables as usually prepared for the table the proportion of carbohydrates is increased and the proportion of protein is diminished. The skins render many of the foods unsightly, hence they are discarded in the preparation for cooking.

When a potato is baked the outer skin is readily separated from the less perceptible layer containing the protein. Potatoes boiled in their skins retain the protein.

In the white potato, of the twenty-two per cent. of carbohydrates, three and two-tenths per cent. is sugar and eighteen and eight-tenths per cent. is starch. In the sweet potato ten and two-tenths per cent. is sugar and sixteen per cent. is starch.

Since sugar digests more quickly than starch, the sweet potato digests more quickly than the white. Because of the large percentage of carbohydrates in each, it is a mistake to eat these two vegetables at the same meal, unless the quantity of each is lessened. For the same reason, bread and potatoes, or rice and potatoes, should not be eaten to any extent at the same meal, unless by one who is doing heavy manual labor, requiring much energy.

_Onions._ Only about four per cent. of the onion represents nourishment; the eleven and three-tenths per cent. of carbohydrates is made up of two and eight-tenths per cent. sugar and the rest of extractives. Of the extractives the volatile oil, which causes the eyes to water when onions are peeled, is the most important.

The onion is not, therefore, so important for its actual nourishing qualities as for its relish and flavor, and for this it is to be commended.

It is a diuretic, encouraging a free action of the kidneys. Because of its diuretic value it is commonly called a healthful food. An onion and lettuce sandwich stimulates the action of the kidneys and is a nerve sedative.

The volatile oil makes the raw onion difficult for some to digest and, in that case, should be omitted from the diet.

_Beets._ There is no starch in beets, their seven and three-tenths per cent. of carbohydrates being sugar. They possess, therefore, more nutritive value than onions, and they are easily digested. It will be noted that it takes many beets to make a pound of sugar.

There are no more delicate or nutritious greens than the stem and leaf of the beet. These greens contain much iron and are valuable aids in building up the iron in the blood, thus aiding in the correction of anemia.

_Carrots._ Carrots are valuable as food chiefly on account of their sugar. They are somewhat more difficult of digestion than beets and they contain more waste. They make a good side dish, boiled and served with butter or cream.

_Turnips._ Turnips have little value as a food. Their nutriment is in the sugar they contain. For those who enjoy the flavor they are a relish, serving as an appetizer, and, like the onion, are to be recommended as a side dish for this purpose.

_Parsnips._ Like carrots, parsnips are chiefly valuable for their sugar and for the extractives which act as appetizers.

Since turnips, carrots, onions, and parsnips owe a part of their nutritive value to the extractives which whet the appetite for other foods, it follows that, if one does not enjoy their flavor or their odor, these vegetables lose in value to that individual as a food. If one does enjoy the flavor, it adds to their food value, therefore _taste for the flavors of all foods should be cultivated_.

* * * * *

[Sidenote: Green Vegetables]

The question may be asked with reason: “Why do we eat green vegetables?” They contain only about four per cent. nutriment, as will be seen in Table II, and are mostly made up of water and pulp. It will be noted that they are distinctly lacking in protein and in carbohydrates; hence, they have little food value.

Some of them, however, contain acids which tend to increase the alkalinity of the blood, and salts which are needed by the system.

Their merit lies in the fact that they have distinct flavors and thus whet the appetite. Another reason why green vegetables are thoroughly enjoyed is because they come in the spring, when the appetite is a little surfeited with the winter foods.

They are diuretic, helping the kidneys and the skin to rid the system of waste.

Because of their bulk of waste they are useful in constipation as they act as a stimulus to the peristaltic action of the bowels; thus they are more laxative to the intestines than the root vegetables, partly because of the salts which they contain and partly because of the undigested vegetable fiber. This vegetable fiber, being coarse, assists in cleansing the mucous lining of the stomach and intestines. They are diuretic and, if for no other reason than for this cleansing of the kidneys, and to make the stomach and intestines more efficient, the use of green vegetables is to be commended, and it is well to eat freely of them.

TABLE II

GREEN VEGETABLES

—————————+—————+—————————+—————+—————————+———————+—————————+—————————
|Water|Nitro- | Fat |Carbo- |Mineral|Cellulose| Fuel
FOOD | per |genous | per |hydrates |Matter |per cent.|Value per
MATERIALS|cent.|Matter |cent.|per cent.| per | | pound
| |per cent.| | | cent. | |Calories
—————————+—————+—————————+—————+—————————+———————+—————————+—————————
Cabbage |89.6 | 1.80 | 0.4 | 5.8 | 1.3 | 1.1 | 165
Spinach |90.6 | 2.50 | 0.5 | 3.8 | 1.7 | 0.9 | 120
Vegetable| | | | | | |
Marrow |94.8 | 0.06 | 0.2 | 2.6 | 0.5 | 1.3 | 120
Tomatoes |91.9 | 1.30 | 0.2 | 5.0 | 0.7 | 1.1 | 105
Lettuce |94.1 | 1.40 | 0.4 | 2.6 | 1.0 | 0.5 | 105
Celery |93.4 | 1.40 | 0.1 | 3.8 | 0.9 | 0.9 | 85
Rhubarb |94.6 | 0.70 | 0.7 | 2.3 | 0.6 | 1.1 | 105
Water | | | | | | |
Cress |93.1 | 0.70 | 0.5 | 8.7 | 1.3 | 0.1 | 110
Cucumbers|95.9 | 0.80 | 0.1 | 2.1 | 0.4 | 0.5 | 10
Asparagus|91.7 | 2.20 | 0.2 | 2.9 | 0.9 | 2.1 | 110
Brussels | | | | | | |
Sprouts |93.7 | 1.50 | 0.1 | 3.4 | 1.3 | 0.4 | 95
Beans | | | | | | |
(string)| 8.92| 2.3 | 0.3 | 7.4 | 0.8 | 7.0 | 195
Beans | | | | | | |
(dried) |12.6 | 22.5 | 1.8 | 59.6 | 3.5 | 0.0 | 1605
Peas | | | | | | |
(green, | | | | | | |
shelled)|74.6 | 7.0 | 0.5 | 16.9 | 1.0 | 0.0 | 465
—————————+—————+—————————+—————+—————————+———————+—————————+—————————

In larger cities, fresh vegetables are in the markets the year around, but if they are raised in greenhouses, or in any way forced, they lack the flavor which comes with natural maturity and they also lack the full amount of iron given by the rays of the sun. If raised in the south and shipped from a distance, they are not fresh and they do not have as good an effect on the system as when fresh and fully matured by the sun.

_Greens_, as spinach, chard, dandelions, and beet tops, as previously stated, contain iron and build red blood corpuscles.

_Cabbage_, of which there are many varieties, contains much sulphur. If fermentation exists in the intestines the sulphur unites with hydrogen causing gas of an unpleasant odor.

They promote the formation of calcium oxalate in the urine and should be avoided as a food by any one inclined to gout, rheumatism, or gall-stones.

Cabbage is usually not well digested by invalids.

Eaten raw, because of its bulk, it is laxative. Some dyspeptics, who cannot digest cooked cabbage, digest raw cabbage readily.

_Celery_ is wholesome when cooked, because of the milk and butter in which it is prepared. Eaten raw the fiber is hard for the digestive juices to dissolve and should be thoroughly masticated. It has little nutritive value save for its appetizing flavor.

Because of the salts, largely sulphates and phosphates, which it contains, celery has been called a nerve food, but the proportion of these is so small that their food value is negligible.

_Tomatoes_ are easily digested and are refreshing. They are not well borne by some and on account of the oxalic acid they contain should not be used by those having an excess of uric acid.

_Asparagus_, because of its delicate flavor and appearance early in spring, is a vegetable universally liked. It is easily digested and may be eaten by invalids; they usually greatly relish it. Its particular food value lies in its sulphur and in its value as an appetizer.

_Rhubarb_ is one of the most wholesome of vegetables and is being much more widely used. Thoroughly cooked it is digestible and a natural laxative.

Its tart flavor and appearance in early spring render it a pleasant change from the ordinary diet. Eaten in excess, like cabbage, it produces calcium oxalate in the urine and should not be eaten in large amounts by those inclined to gout.

All fresh vegetables should be masticated to almost a fluid consistency; otherwise, they are difficult of digestion, containing, as they do, so much fiber.

* * * * *

[Sidenote: Fruits]

Technically speaking, fruits include all plant products which bear or contain a seed. They are valuable for their acids and organic salts—citrates, malates, or tartrates of potassium, sodium, magnesium, and calcium.

They are composed for the most part of starch, sugar, water, and various organic acids, cellulose, and pectin. (Pectin is the substance which jellies under heat.) Fruits which do not contain pectin must be combined with others which do, or with gelatin, if jelly from them is desired.

The organic acids in fruits are readily split up in the body, and form alkalis. For this reason acid fruits are useful in certain acid conditions of the stomach, because they combine with the stomach acids, liberating substances which cause an alkaline reaction.

The citrus fruits—oranges, lemons, grapefruit and limes—are rich in citric acid.

Malic acid is found in gooseberries, peaches, pears, apples, currants, and apricots.

Tartaric acid is prominent in grapes.

The value of fruits as a food depends largely on the amount of starch and sugar they contain, though their agreeable odor and taste, by furnishing variety in the diet, render them, also, of great value as appetizers.

As a rule they contain too much water to be of great food value if eaten alone.

The organic acids and salts contained in fruits are of value as they stimulate the activity of the kidneys and lessen the acidity of the urine. The urine may even be rendered alkaline by them; hence, when a test shows evidence of too much uric acid, acid fruits are used to neutralize the acids in the tissues, particularly the acids of the citrus fruits.

The fruit juices are readily absorbed and the potassium calcium, sodium, and magnesium they contain are liberated with the formation of alkaline carbonates.

These alkalis are largely eliminated through the kidneys, which accounts for the diuretic effect of fruits, their acids and salts stimulating the activity of the kidneys.

The seeds in the small fruits are not digested, but they serve the purpose of increasing intestinal peristalsis and of assisting the movement of the contents of the intestines. The skin and the fiber of fruits also assist the intestines in this way, just as the fiber in vegetables does.

All acid fruits—particularly lemons, limes, grapefruit, and oranges—stimulate the action of the skin as well as the kidneys and whenever the kidneys and skin are not sufficiently active, these fruits should be eaten freely.

In case of an excess of hydrochloric acid in the stomach, lemon juice or citrus fruits are valuable about half an hour _before_ a meal, as when taken on an empty stomach they decrease the secretion of hydrochloric acid.

When the secretion of hydrochloric acid is limited, acids are given _after_ a meal to supplement the deficiency, or stimulate the glands to activity.

_Sweet_ or _bland_ fruits are those containing a lesser percentage of acids. Among these are pears, raspberries, grapes, bananas, blackberries, blueberries, melons, and some peaches, apples, and plums.

Of this class of fruits, dates, figs, prunes, and grapes (raisins), furnish most nutriment, because, as will be noted by Table III, these fruits contain a large amount of carbohydrates in the form of sugar.

The protein in these sweet fruits is largely in the seeds and, as the seeds are not digested, they have no real food value for the individual.

Figs and prunes, peaches, apples, and berries are laxative—probably the laxative action of figs and berries is due to the seeds, and of the others to the salts and acids they contain, and to the cellulose or fibrous material which furnishes bulk.

TABLE III

FRUITS

———————————————+—————+———————+———————+————————+—————+—————————+—————
FOOD |Water|Protein|Ether |Carbo- |Ash |Cellulose|Acids
MATERIALS |per |per |Extract|hydrates|per |per cent.|per
|cent.|cent. |per |per |cent.| |cent.
| | |cent. |cent. | | |
———————————————+—————+———————+———————+————————+—————+—————————+—————
Apples |82.50| 0.40 | 0.5 | 12.5 | 0.4 | 2.7 | 1.0
Apricots |85.00| 1.10 | 0.6 | 12.4 | 0.5 | 3.1 | 1.0
Peaches |88.80| 0.50 | 0.2 | 5.8 | 0.6 | 3.4 | 0.7
Plums |78.40| 1.00 | 0.2 | 14.8 | 0.5 | 4.3 | 1.0
Cherries |84.00| 0.80 | 0.8 | 10.0 | 0.6 | 3.8 | 1.0
Gooseberries |86.00| 0.40 | 0.8 | 8.9 | 0.5 | 2.7 | 1.5
Currants |85.20| 0.40 | 0.8 | 7.9 | 0.5 | 4.6 | 1.4
Strawberries |89.10| 1.00 | 0.5 | 6.3 | 0.7 | 2.2 | 1.0
Whortleberries |76.30| 0.70 | 3.0 | 5.8 | 0.4 | 12.2 | 1.6
Cranberries |86.50| 0.50 | 0.7 | 3.9 | 0.2 | 6.2 | 2.2
Oranges |86.70| 0.90 | 0.6 | 8.7 | 0.6 | 1.5 | 1.8
Lemons |89.3 | 1.00 | 0.9 | 8.3 | 0.5 | 1.5 | 1.8
Pineapples |89.3 | 0.04 | 0.3 | 9.7 | 0.3 | 1.5 | 7.0

Pears |83.90| 0.40 | 0.6 | 11.5 | 0.4 | 3.1 | 0.1
Blackberries |88.90| 0.90 | 2.1 | 2.3 | 0.6 | 5.2 | 1.6
Raspberries |84.40| 1.00 | 2.1 | 5.2 | 0.6 | 7.4 | 1.4
Mulberries |84.70| 0.30 | 0.7 | 11.4 | 0.6 | 0.9 | 1.8
Grapes |79.00| 1.00 | 1.0 | 15.5 | 0.5 | 2.5 | 0.5
Watermelons |92.90| 0.30 | 0.1 | 6.5 | 0.2 | 1.0 | 0.5
Bananas |74.00| 1.50 | 0.7 | 22.9 | 0.9 | 0.2 | 0.5

Dates, dried | 2.08| 4.40 | 2.1 | 65.1 | 1.5 | 5.5 | 7.0
Figs, dried | 2.00| 5.50 | 0.9 | 62.8 | 2.3 | 7.3 | 1.2
Prunes, dried | 2.64| 2.40 | 0.8 | 66.2 | 1.5 | 7.3 | 2.7
Raisins |10.60| 2.50 | 4.7 | 74.7 | 3.1 | 1.7 | 2.7
———————————————+—————+———————+———————+————————+—————+—————————+—————

The astringent and acid taste of unripe fruits is due to the tannin and the acids. Oxygen is necessary to ripen fruits and the slow natural maturing of the fruit on the tree enables the oxygen to enter into combination with these substances, lessening their reaction and altering the starch into glucose or levulose.

Fruits ripened artificially lack this chemical action of sun and oxygen, hence the decreased palatability and digestibility of fruits so ripened. If underripe fruits are freely eaten they ferment in the alimentary tract and this fermentation causes the colic, vomiting, and diarrhea so often experienced. Overripe fruit, from the decomposition products which have already begun to form and which are further released in the stomach or bowels, may produce the same results.

Care should therefore be exercised to select thoroughly ripe fruits which have not begun to decay.

In order to reach their destination in fair condition, outwardly, many fruits are picked before they are ripe. Bananas are commonly picked green, because they decay so quickly that if they were picked ripe they would spoil before reaching the northern markets.

One test of a naturally ripened apple is to cut it with a steel knife—if the blade turns black, or if the cut surface of the apple turns brown in a few minutes, it should not be eaten, for it indicates an excess of tannin. It is this tannin which gives the small boy excruciating pains from his green apples.

It will be recalled that the tannin from the bark of trees toughens the skin of animals and forms leather. The effect on the membrane of the stomach and intestines, from the tannin in food, is not so pronounced, because of the activity and resistance of living matter.

The juice of lemons and oranges is most valuable in seasickness and scurvy, and is of benefit in nausea. A slice of lemon will often clear a coated tongue and give a refreshing sense of cleanliness to the mouth, especially in feverish conditions. Sour lemonade is one of the best drinks in summer because of its thirst-allaying qualities.

Table III shows that _bananas_ contain nearly twenty-three per cent. of carbohydrates, which, in an immature state, are largely starches. The natural ripening process changes the starch to sugar, thus making them more easily digested. The starch globules, when not matured on the tree, are not easily broken and are thus difficult of digestion.

Bananas should not be given to children under two years of age because before this age the ptyalin and pancreatin are not sufficiently developed to digest the starch.

Many of the inhabitants of the tropics use bananas almost to the exclusion of other food and appear well nourished. They obtain them from the tree when the fruit has thoroughly ripened, the starch having been transformed by Nature into an easily digested product.

The reason many find they cannot digest bananas, as purchased in our markets, is due to the fact that the fruit is immature and unripe.

The banana meal or flour is usually thoroughly digestible, is nourishing, and has an agreeable taste. Invalids can often take banana meal in the form of gruel; it makes an appreciated addition to a limited diet. Made into a porridge and eaten with cream it is valuable in conditions of inflammation of the gastro-intestinal tract. The addition of a few drops of lemon juice renders it palatable to those who like an acid flavor. Children enjoy it as a variation from cereals. It is relished by typhoid fever patients as a change from milk.

It must be carefully cooked and well prepared as, like oatmeal, it can be spoiled by insufficient or poor cooking. Owing to the limited demand it is not obtainable in all markets, as it has not yet become popularized.

_Grapes_, because of their wholesome qualities, are useful to the system, as they contain sodium, iron, magnesium, potassium, and calcium. Because of their appetizing flavor they are universally enjoyed, and because they are cheap are universally used. The skins and seeds are indigestible and, if swallowed, may cause severe irritation or obstruction of the intestines. Grapes are rich in sugar, and on this account must not be eaten by diabetics.

Grape juice, when unfermented, is a valuable drink, in health, or for the convalescent. It is agreeable in taste and is mildly laxative. Added to other fruit juices, as lemon or orange, it allays thirst and furnishes a pleasant flavor, but on account of its high percentage of sugar does not allay thirst when used alone.

_Apples_, so universally used, are easily digestible when ripe, and may be prepared in so many ways that they constitute a valuable addition to the diet. Their laxative qualities, when taken on an empty stomach, as before breakfast, or just before retiring, are well known. They are thus valuable in constipation, and in some forms of dyspepsia may, with benefit, be eaten raw.

Apples should be thoroughly masticated.

The apple peel contains potassium salts and should be eaten with the fruit.

Most invalids digest apples better if they are cooked, especially baked. Stewed apples may have the beaten white of eggs whipped into them and invalids who revolt against eggs can take them thus prepared.

Because of the sugar necessary in cooking them they should be avoided by diabetics, and in conditions in which there is irritation of the gastro-intestinal tract.

_Quinces_ are indigestible when raw, but well baked and eaten with cream are appetizing and nourishing.

_Pineapples_, if thoroughly ripe, contain a ferment which will digest protein, rapidly softening and disintegrating the tissue of meat. Like the pancreatic ferment it acts in both alkaline and acid mediums. Pineapple juice, therefore, is exceedingly valuable as an addition to the diet. The coarse fibers also have a laxative action. Care must be taken, however, to use this fruit only when it is well ripened, as when green, it is indigestible.

The juice of pineapple, because of the action of the ferment in dissolving tissue, is valuable in many forms of sore throat, particularly when accompanied by an ulcerous condition. The effort should be made to hold it in the mouth, allowing it to trickle down the throat by degrees.

_Dried fruits_ are less palatable than fresh. Many of them, as prunes and raisins, are nourishing, but others, as citron, are indigestible, and should be finely chopped if used as flavoring.

Dried or evaporated fruits, through the action of heat, either artificial or from the rays of the sun, have lost the water they contained, and are preserved by their own sugar.

Dried grapes, or raisins, because of their sugar, soon satiate the appetite if eaten raw, but if cooked or added to cereals, puddings, or breads, enhance the palatability and nourishing qualities of these foods.

Dates and figs used in the same way, in cereals or puddings, are equally valuable.

Dried currants are the most indigestible of the dried fruits, owing to their large amount of skin in proportion to the nutriment.

_NITROGENOUS FOODS_

As previously stated, in a mixed diet, meat and eggs are the chief sources of nitrogenous foods. Next to these come the legumes.

* * * * *

[Sidenote: Meat]

Meat is composed largely of muscle fiber and contains connective tissue and fat. It has been estimated that beef contains one-third nutritive material, the other two-thirds being water and bone. Fat meat contains less nitrogenous material and less water than lean meat.

Lean meat is almost entirely digested in the stomach by the gastric juice, which changes it into peptone. It is needless to say that it should be thoroughly masticated, that the gastric juice may promptly act on it. If any part passes into the intestine undigested, the process is continued by the trypsin of the pancreatic juice.

The peptone is absorbed and carried by the blood and lymph to all tissues of the body, where it is used for growth and repair. As stated under “Heat and Energy,” any excess of protein above that needed for growth and repair is oxidized if sufficient oxygen is breathed, yielding energy and heat, and the waste is eliminated through the kidneys and the bile.

For purposes of comparison, one pound of beef has been said to equal in nutritive value, two and one-half pints or five glasses of milk, one-half pound (two-thirds of an ordinary baker’s loaf) of bread, and three eggs. However, these values vary.

TABLE IV

ANIMAL FOODS

——————————————————+—————+———————+—————+—————————+—————+——————————
FOOD MATERIALS |Water|Protein|Fat |Carbo- |Ash |Fuel Value
|per |per |per |hydrates |per |per pound
|cent.|cent. |cent.|per cent.|cent.|Calories
——————————————————+—————+———————+—————+—————————+—————+——————————
Beef, Fresh | 54.0| 17.0 | 19.0| .... | 0.7 | 1105
Flank | 54.0| 17.0 | 19.0| .... | 0.7 | 1105
Porterhouse | 52.4| 19.1 | 17.9| .... | 0.8 | 1100
Sirloin steak | 54.0| 16.5 | 16.1| .... | 0.9 | 975
Round | 60.7| 19.0 | 12.8| .... | 1.0 | 890
Rump | 45.0| 13.8 | 20.2| .... | 0.7 | 1090
Corned beef | 49.2| 14.3 | 23.8| .... | 4.6 | 1245
| | | | | |
Veal: | | | | | |
Leg cutlets | 68.3| 20.1 | 7.5| .... | 1.0 | 695
Fore quarter | 54.2| 15.1 | 6.0| .... | 0.7 | 535
| | | | | |
Mutton: | | | | | |
Leg, hind | 51.2| 15.1 | 14.7| .... | 0.8 | 890
Loin chops | 42.0| 13.5 | 28.3| .... | 0.7 | 1415
Lamb | 49.2| 15.6 | 16.3| .... | 0.85| 967
| | | | | |
Ham: | | | | | |
Loin chops | 41.8| 13.4 | 24.2| .... | 0.8 | 1245
Ham, smoked | 34.8| 14.2 | 33.4| .... | 4.2 | 1635
| | | | | |
Sausage: | | | | | |
Frankfurter | 57.2| 19.6 | 18.6| 1.1 | 3.4 | 1155
| | | | | |
Poultry: | | | | | |
Fowls | 47.1| 13.7 | 12.3| .... | 0.7 | 765
Goose | 38.5| 13.4 | 29.8| .... | 0.7 | 1475
Turkey | 42.4| 16.1 | 18.4| .... | 0.8 | 1060
| | | | | |
Animal Viscera: | | | | | |
Liver (sheep) | 61.2| 23.1 | 9.0| 5.0 | ....| ....
Sweetbreads | 70.9| 16.8 | 12.1| .... | 1.6 | ....
Tongue, smoked | | | | | |
and salted | 35.7| 24.3 | 31.6| .... | 8.5 | ....
| | | | | |
Brain: | 80.6| 8.8 | 9.3| .... | 1.1 | ....
| | | | | |
Fresh Fish: | | | | | |
Bass large- | | | | | |
mouthed| | | | | |
Black, dressed | 41.9| 10.3 | 0.5| .... | 0.6 | 215
Cod steaks | 72.4| 16.9 | 0.5| .... | 1.0 | 335
Shad roe | 71.2| 23.4 | 3.8| .... | 1.6 | 595
Whitefish, | 46.1| 10.2 | 1.3| .... | 0.7 | 245
dressed | | | | | |
Preserved Fish: | | | | | |
Halibut, salted, | | | | | |
smoked and dried | 46.0| 19.1 | 14.0| .... | 1.9 | 945
Sardines, canned | 53.6| 24.0 | 12.1| .... | 5.3 | 955
Salmon, canned | 59.3| 19.3 | 15.3| .... | 1.2 | 1005
| | | | | |
Mollusks: | | | | | |
Oysters, solid | 88.3| 6.1 | 1.4| 3.3 | 0.9 | 235
Round clams | | | | | |
removed from | 80.8| 10.6 | 1.1| 5.1 | 2.3 | 340
shell | | | | | |
Mussels | 42.7| 4.4 | 0.5| 2.1 | 1.0 | 140
| | | | | |
Crustaceans: | | | | | |
Lobster, in shell| 31.1| 5.5 | 0.7| .... | 0.6 | 130
Crab, in shell | 34.1| 7.3 | 0.9| 0.5 | 1.4 | 185
Shrimp, canned | 70.8| 25.4 | 1.0| 0.2 | 2.6 | 520
Terrapin, turtle,| 17.4| 4.2 | 0.7| .... | 0.2 | 105
etc. | | | | | |
——————————————————+—————+———————+—————+—————————+—————+——————————

The amount of fat in meat varies from two to forty per cent., according to the animal and to its condition at the time of killing.

The best meats are from young animals which have been kept fat and have not been subjected to any work to toughen the muscles.

It is possible to combine the fat and the lean of meat so as to meet the requirements of the body without waste. About ninety-seven per cent. of meat is assimilated by the system, while a large part of the vegetable matter consumed is excreted as refuse.

The compounds contained in animal foods are much like those of the body, therefore they require comparatively little digestion to prepare them for assimilation—this work having been done by the animal—while the vegetable compounds require much change by the digestive system before they can be used in the body.

The proportion of _albuminoids_, _gelatinoids_, and _extractives_ in meat vary with different meats and with different cuts of the same meat.

The _albuminoids_ of meat include the meat tissue, or the muscle cells. These constitute by far the greater part of the meat.

The _gelatinoids_ are derived from the connective tissue forming the sheath of the muscle and of bundles of muscles, the skin, tendons, and the casing of bone. Gelatins are made from these and, if pure and prepared in a cleanly manner, they are wholesome.

Gelatin is distinguishable in rich meat soups, which jelly when cool.

The gelatinoids alone have not a large nutritive value; they serve to spare the albumin from being used, though they cannot replace albumin in the diet. They also, to some extent, keep the muscles from being consumed when starches, sugars, and fats are lacking.

The _extractives_ are found most abundantly in the flesh of animals and birds noted for their muscular activity, as in game. Some of them exert a stimulant action on the nervous system and others are appetizers, giving to cooked meats, broths, etc., their pleasing flavor. In case of anemia, in which it is necessary to build red blood corpuscles, the blood of beef, the thought of which is usually repellent, may be made very palatable if it is heated sufficiently to bring out the flavor of the extractives, and then seasoned.

Unless the beef extracts on the market contain the blood tissue, in addition to the extractives, they are not particularly nourishing and are only valuable in soups, etc., as appetizers.

Soups for nourishment should be made by cooking the bones, connective tissue, and a part of the meat. Bones and connective tissue alone make an appetizing soup, but it contains little nutriment.

One reason why meat soups should constitute the first course at dinner is because the extractives stimulate the appetite and start the flow of gastric juices. Bouillons contain no nourishment, but they may be used as stimulant restoratives to the muscles, or as a basis for vegetables, rice, or barley to give them flavor.

Roasted flesh seems to be more completely digested than boiled meat; raw meat is more easily digested than cooked; rare meat is more easily digested than that thoroughly cooked.

Roasted young chicken and veal are tender, easily masticated, and easily and rapidly digested in the stomach. This is one reason why the white meats are considered a good diet for the invalid, though veal is usually avoided in cases of dyspepsia, as, if too young, it may cause diarrhea; if too old, it is less digestible than beef.

Fat meats remain in the stomach a much longer time than lean meats; thus, gastric digestion of pork, which usually contains much fat, is especially difficult, requiring from three and one-half to four hours (see page 22).

Preserved and canned meats should be eaten with the utmost caution, care being taken to know that they are put up by firms which use extreme care in their preparation. Inferior meat is sometimes used in the preparation of these foods. If meats are not fresh and the canning not carefully done, they may become putrid after being put up.

_Fish_ and _sea foods_ are, many of them, rich in protein, as noted in Table IV. They should never be used unless absolutely fresh.

The idea is prevalent that fish is a brain food. Fish is easily digested and builds brain as well as other tissue, but no more readily than beef does, or any easily digested, absorbed and assimilated food which contains a goodly proportion of protein.

_Lobsters_ are difficult of digestion and contain little nutrition, so are not valuable as a food, though they are relished by many on account of their flavor.

_Oysters_, raw, are easier to digest than when cooked. Oysters should not be eaten during the spawning season from May to September.

_Mussels_ are nutritious when well prepared and are rapidly gaining in popularity.

_Clams_ furnish a valuable and nutritious food when prepared in chowder form. Clam broth will often be retained on an irritable stomach when other food is rejected by it.

Care should be taken to ascertain the method of their production as typhoid fever has been contracted from eating shell fish whose feeding beds were near or in polluted water.

* * * * *

[Sidenote: Eggs]

Eggs are excellent articles of food for nutrition and for tissue building. They have practically the same value in the diet as meat, and make a very good substitute for meat. Egg yolk in abundance is often prescribed when it is necessary to supply a very nutritious and easily assimilated diet.

Eggs consist chiefly of two nutrients—protein and fat (ten per cent.). Because they contain so large a proportion of protein they are classified as nitrogenous foods.

The yolk, which is about one-third fat, contains iron, sulphur, potassium, calcium, magnesium, and phosphorus. The white contains some fat and phosphorus. The white and the yolk contain equal quantities of protein. The white of the egg is almost pure albumin.

The dark stain made by eggs on silver is due to the sulphur.

The iron in the yolk is a valuable assistant in building red blood corpuscles.

Eggs, in common with other proteins, are changed, mostly in the stomach, into peptone. That not digested in the stomach, as is the case with other proteins, is changed in the intestine.

If the egg is old, or if its absorption is delayed in the intestine, it decomposes, producing gas, and may cause intestinal disorder. For this reason no stale egg should ever be served, especially to an invalid.

One reason why eggs disagree with some is because too much fat is eaten at the same time. Egg yolk contains fat and if much extra fat is eaten indigestion and fermentation in the intestine may result. This is particularly true in those who digest fat with difficulty.

When eggs seem to disagree or the system does not assimilate them well on account of the fat in the yolk, and eggs are desirable to supply the protein in the diet, the whites, which contain practically no fat, may be used. They should be well beaten and if digestion is weak they may be mixed with fruit juices.

The citric acid in lemons and oranges partially digests the egg, the gastric juice quickly changing it to peptone.

One method of preparing eggs, which is especially valuable for those having delicate stomachs, is in egg lemonade or orangeade. Thoroughly beat the egg, add the juice of half a lemon or orange, sugar to taste, and fill the glass with water.

Grape juice, cream, and cocoa, if assimilated, may be used in place of lemon or orange, in order to give variety when it is necessary to use eggs freely.

Eggnog is another means of taking raw eggs.

One method of testing the freshness of eggs is to drop them into a strong, salt brine made by adding two ounces of salt to a pint of water. A fresh egg will at once sink to the bottom. If the egg is three days old the surface of the shell will be even with the surface of the water and an egg two weeks old will float mostly above the surface.

The opinion is prevalent that a hard-boiled egg is difficult of digestion, but this depends entirely on the mastication. If it is masticated so that it is a pulp before being swallowed, a hard-boiled egg is readily digested.

A soft-boiled egg should not be boiled longer than three or four minutes, or better, should be put into warm water, be allowed to come to a boil, then set off the fire and the egg be allowed to remain in the water for ten minutes. This method cooks the egg through more evenly.

Another method of cooking the yolk evenly with the white is to put the egg in cold water, let the water come to a boil, and again immerse the egg in cold water. The immersing in cold water after boiling makes hard-boiled eggs peel readily.

_CARBO-NITROGENOUS FOODS_

Under this class come cereals, legumes, nuts, milk, and milk products. In these foods the nitrogenous and carbonaceous elements are more evenly proportioned than in either the carbonaceous or nitrogenous groups. The different food elements in this group are so evenly divided that one could live for a considerable length of time on any one food. Some animals build flesh from nuts alone, while the herbivorous animals live on cereals and plants.

* * * * *

[Sidenote: Cereals]

Under cereals, used by man for food, come wheat, oats, rye, barley, rice, and corn. As will be noted by Table V, cereals contain a large proportion of starch and are therefore used largely for heat and energy. Rice contains the largest proportion and next to rice, wheat flour.

TABLE V

CEREALS

—————————————————+—————+———————+—————+—————————+—————————+——————
| | | | _Carbohydrates_ |
| | | +—————————+—————————+
FOOD MATERIALS |Water|Protein|Fat |Starch, |Crude | Ash
|per |per |per | etc. |fiber | per
|cent.|cent. |cent.|per cent.|per cent.| cent.
—————————————————+—————+———————+—————+—————————+—————————+——————
Wheat |10.4 | 12.1 | 2.1| 71.6 | 1.8 | 1.9
Rice |12.4 | 7.4 | 0.4| 79.2 | 0.2 | 0.4
Oats |11.0 | 11.8 | 5.0| 59.7 | 9.5 | 3.0
Rye |11.6 | 10.6 | 1.7| 72.0 | 1.7 | 1.9
Breads and | | | | | |
Crackers: | | | | | |
Wheat bread |32.5 | 8.8 | 1.9| 55.8 | .... | 1.0
Graham bread |34.2 | 9.5 | 1.4| 53.3 | .... | 1.6
Rye bread |30.0 | 3.4 | 0.5| 59.7 | .... | 1.4
Soda crackers | 8.0 | 10.3 | 9.4| 70.5 | .... | 1.8
Graham crackers | 5.0 | 9.8 | 13.5| 69.7 | .... | 2.0
Oatmeal crackers| 4.9 | 10.4 | 13.7| 69.6 | .... | 1.4
Oyster crackers | 3.8 | 11.3 | 4.8| 77.5 | .... | 2.6
Macaroni |13.1 | 9.0 | 0.3| 76.8 | .... | 0.8
Flours and Meals:| | | | | |
Flour, wheat |12.5 | 11.0 | 1.0| 74.9 | .... | 0.5
Corn Meal |15.0 | 9.2 | 3.8| 70.6 | .... | 1.4
Oatmeal | 7.6 | 15.1 | 7.1| 68.2 | .... | 2.0
—————————————————+—————+———————+—————+—————————+—————————+——————

The values as given in the table refer to the whole of the grain. When the outer coverings are removed, as in the white flour and the outer covering of rice, the proportion of carbohydrates is increased and the protein and ash are almost entirely eliminated.

There is no part of the world, except the Arctic regions, where cereals are not extensively cultivated. From the oats and rye of the north, to the rice of the hot countries, grains of some kind are staple foods.

An idea of the importance of cereal foods in the diet may be gathered from the following data, based on the results obtained in dietary studies with a large number of American families: Vegetable foods, including flour, bread, and other cereal products, furnished 55 per cent. of the total food, 39 per cent. of the protein, 8 per cent. of the fat, and 95 per cent. of the carbohydrates of the diet. The amounts which cereal foods alone supplied were 22 per cent. of the total food, 31 per cent. of the protein, 7 per cent. of the fat and 55 per cent. of the total carbohydrates—that is, about three-quarters of the vegetable protein, one-half of the carbohydrates, and seven-eighths of the vegetable fat were supplied by the cereals. Oat, rice, and wheat breakfast foods together furnished about 2 per cent. of the total food in protein, 1 per cent. of the total fat, and 4 per cent. of the carbohydrates of the ordinary mixed diet, as shown by the statistics cited. These percentage values are not high in themselves, but it must be remembered that they represent large quantities when we consider the food consumed by a family in a year.[4]

If one’s work calls for extreme muscular exertion, the cereals may be eaten freely, but if one’s habits are sedentary, and the cereals are used in excess, there is danger of clogging the system with too much starch. Indeed, for one whose occupation is indoors and requires little muscular activity, a very little cereal food, such as bread, cake, etc., will suffice; the carbohydrates will be supplied, in sufficient quantity, in vegetables.

Mineral matter is supplied in sufficient quantity in almost all classes of foods.

Cereals and legumes supply nutrients at less price than any class of foods; therefore a vegetarian diet involves less expense than the mixed diet. An entirely vegetarian diet, however, gradually induces a condition of muscular weakness in many people, resulting in a loss of strength. A well-proportioned mixed diet is best to give strength and activity of both body and mind.

Meat, eggs, and milk, which usually supply the proteins, are the most expensive foods, and when these, for any cause, are eliminated, a large proportion of proteins should be supplied by the legumes.

* * * * *

[Sidenote: Wheat]

Perhaps no food is as commonly used as wheat in its various forms. It is composed of:

1. The nitrogenous or protein compound, chiefly represented in the cerealin and the gluten of the bran. This is removed from white flour and from much of the so-called “whole wheat” flour.

2. The starch—the center or white part of the kernel.

3. The fats, occurring chiefly in the germ of the grain.

4. The phosphorus compounds, iron, and lime, found in the bran.

The kernel of wheat consists of the bran or covering, which surrounds the white, pulpy mass of starch within. In the lower end of the kernel is the germ.

_Flour._ In the old-time process of making flour the wheat was crushed between stones and then sifted, first, through a sieve, which separated the outer shell of the bran; then through bolting cloth, which separated the white pulp from the inner bran coating. It was not ground as fine as in the present process, thus the gluten, phosphorus, and iron (all valuable substances) were, in the old process, nearly all left out of the white flour. The second bran coating, left by the second sifting, was not so coarse as the outer shell but coarser than the inner. Care was not formerly observed in having the grain clean before grinding, the bran containing chaff and dirt, so that it was not used as food but was considered valuable for stock, and was called “middlings.”

In the modern process of crushing the wheat between steel rollers, the white flour of to-day contains more of the protein from the inner coat of the bran than the white flour of the old process; hence, it is more nutritious.

_Bran._ Objection is sometimes made to bran because the cellulose shell is not digested, but bran contains much protein and mineral matter and even though it is crude fiber, as previously stated, this fiber has a value as a cleanser for the lining of the stomach and intestines, and for increasing peristalsis, thus encouraging the flow of digestive juices and the elimination of waste. In bread or breakfast foods, it is desirable to retain it for its laxative effect.

Bran has three coats—the tough, glossy outside, within this a coat containing most of the coloring matter, and a third coat, containing a special kind of protein, known as cerealin. The two outer layers contain phosphorus compounds, lime, and iron. All three coats contain gluten.

_Gluten flour_ is made of the gluten of wheat. It is a valuable, easily digested food, containing a large proportion of protein and little starch. Gluten bread is used by those who wish to reduce in flesh and in diabetic cases.

_Whole wheat_ flour does not contain the whole of the wheat, as the name implies; it, however, does contain all the proteins of the endosperm and the gluten and oil of the germ, together with all of the starch. As a flour, therefore, it is a more balanced food than the white flour, because it contains more nitrogenous elements.

_Graham flour_ is made from the entire wheat kernel with the exception of the outermost scale of the bran. It contains the starch, gluten phosphorus compounds, iron, and lime. It is the most desirable of the flours because, containing the bran, it assists in digestion and elimination, and the phosphorus, iron, and lime, are valuable body builders.

_Nutri meal_ is much the same as Graham flour, the chief difference being that the bran is ground finer. The wheat is ground between hot rollers, the heat bringing out the nutty flavor of the bran. Bread made from it is not only nutritious, but delicious in flavor. It contains all of the nutrition of the wheat.

_Bread._ As must be implied from the foregoing, the nutri meal, or graham flours are necessary for bread if it is to be used as a complete food, the “staff of life.” The white bread is made from flour which is almost pure starch; the lime, phosphorus compounds, and iron are removed.

Perhaps no form of prepared food has been longer in vogue than bread. It has been known since history began. When the entire wheat kernel is used it probably maintains and supports life and strength better than any single food, but bread is not the “staff of life” unless the entire kernel is in the flour.

Children should be given Graham bread or Graham crackers containing the whole of the grain in order to obtain the balanced food and the nutritive materials which are not obtained in bread made of white flour. Lime for the teeth and the growing bones is in the bran.

The more porous the bread the more easily it digests. When full of pores, it is more readily mixed with the digestive juices.

The pores in bread are produced by the effort of the gas, released by the yeast, to escape. When mixed with water, the flour forms a tenacious body which, when warm, expands under the pressure of the gas from the yeast, until the dough is full of gas-filled holes. The walls of gluten do not allow the gas to escape, and thus the dough is made light and porous. The more gluten the flour holds, the more water the dough will take up and the greater will be the yield of bread; hence, the more gluten, the more valuable the flour. If the bread is not porous, the fermentation is not complete, and the bread is heavy.

The albumin in the walls of the expanding bubbles causes substances which contain beaten eggs to be more porous when baked.

_Yeast_ is a plant fungus. In its feeding, the plant consumes sugar, changing it into alcohol and carbon dioxid. If the bread contains no sugar the yeast plant will change the starch in the flour into sugar for its feeding.

Many housewives, realizing that the bread begins to “rise” quicker if it contains sugar, put a little into the sponge. Unless a large quantity of sugar is put in, the yeast will consume it and the bread will not have an unduly sweet taste.

As the yeast causes fermentation, alcohol forms in the dough. This is driven off in the baking. If the bread is not thoroughly baked, fermentation continues and the bread turns sour.

Bread is not thoroughly baked until fermentation ceases. It is claimed that fermentation does not entirely cease with one baking; this is the basis of the theory, held by some, that bread should be twice baked. The average housekeeper bakes an ordinary loaf one hour.

Time must be given for the products of fermentation to evaporate, during the cooling of the bread, before it is eaten.

Hot or insufficiently cooked bread is difficult of digestion, because it becomes more or less soggy on entering the mouth and the stomach, and the saliva and gastric juices cannot so readily mix with it.

The best flour for bread is that made from the spring wheat, grown in cooler climates, because it is richer in gluten than the winter wheat. The winter wheat flour is used more for cakes and pastries.

Bread made with milk, is, of course, richer and more nutritious than that made with water, and bread made with potato water contains more starch; both of these retain their moisture longer than bread made without them.

_Mold_, which sometimes forms on bread, is, like the yeast, a minute plant. It is floating about everywhere in the air, ready to settle down wherever it finds a suitable home. Moisture and heat favor its growth; hence bread should be thoroughly cooled before it is put into a jar or bread box. The bread box should be ventilated and kept in a cool place.

_Rye bread_ contains a little more starch and less protein than wheat bread. It contains more water and holds its moisture longer.

_Biscuits._ The objection to eating hot bread does not hold for baking powder or soda biscuits, if well cooked, because these cool more rapidly and they do not contain the yeast plant; hence, they do not ferment as does the bread.

_Baking powder_ is made from bicarbonate of soda (baking soda) and cream of tartar. When these are brought in contact with moisture, carbon dioxid is liberated, and in the effort to escape it causes the dough to expand and become light.

Breads made with pure baking powder are wholesome and, when light, are digestible. When made with cheap baking powder, however, in which alum or ammonia is employed, the stomach may be irritated by the chemical substances contained.

The reason that the cook attempts to bake her biscuits, or anything made with baking powder, as quickly as possible after the baking powder comes in contact with the moisture, is that the dough may have the full effect of the expansion of the gas. If the room in which she mixes her dough is cool, or if her biscuit dough is left in a cool place, this is not important, as heat and moisture are both required for full combustion. Enough baking powder biscuit dough may be mixed at one time to provide biscuits every morning for a week, if buried in flour immediately after mixing so that it is kept cool and from the air. A portion may be cut off each morning and the remainder again buried in the flour.

_Macaroni_ and _spaghetti_ are made from a special wheat flour known as Durum. They contain about seventy-seven per cent. of starch, little fat, and little protein. They may take the place of bread, rice, or potato at a meal.

_Rice_ is a staple cereal in all tropical and temperate climates. It requires special machinery to remove the husk and the dark, outer skin of the kernel.

The polished rice commonly used, is almost pure starch, and, like white flour, lacks the nutritive qualities contained in the husk or covering.

It is seldom eaten within three months after harvesting and it is considered even better after two or three years. It requires thorough cooking.