Fruits may, like vegetables, be classified as flavor fruits and food fruits, and again these two classes will run together so that we shall have difficulty in deciding where certain ones belong. The apple, the orange, the strawberry, although all having a certain food value, are used so largely for their flavor and to give variety, that these may well be put under the head of the flavor fruits. Bananas form, perhaps, the best common example of the food fruits. Bread fruit, so largely used in the tropics, is another representative of this class.
From a dietetic standpoint the most important function of fruits is that of furnishing mineral salts and organic acids to the body. The potash salts are considered especially important. Some fruits, like the pineapple, contain ferments that are said to be aids to digestion. Fruits are generally laxative in effect, - apples, figs, prunes, peaches and berries are particularly effective in this respect, especially if taken between meals or at the beginning of a meal.
Their chief nutritive value is given to fruits by the carbohydrate group. This is largely in the form of sugar, while the remainder consists chiefly of vegetable gums, among which may be included the "pectin bodies" that give to fruits their power to form jelly. Starch may be present in unripe fruits, but disappears as the fruit ripens. Bananas, as we use them, contain a small amount of starch. Of fresh fruits very few contain more than one per cent of nitrogenous matter, not all of which is proteid.
Dried fruits may be without question put under the food fruits, dates containing sixty-six per cent of carbohydrate, prunes approximately the same amount, figs about sixty-three per cent, while raisins furnish seventy-five per cent. Raisins in this respect stand almost at the head of the list of concentrated foods since they furnish so much nutriment in so small a bulk. When fresh fruits are not obtainable dried fruits may well take their place. These are usually less expensive than fresh fruits, and properly cooked go far to make up for the absence of the fresh varieties.
COMPOSITION OF AN APPLE.
Canned fruits are increasingly used, and many who formerly thought it necessary to put up large amounts of fruit at home, are now purchasing those canned on a commercial scale. Whether this is a wise thing or not depends on the amount of fruit available for the housekeeper at a low cost, the price of sugar, and the time and strength at her disposal. Often the fruit commercially canned is really superior to that prepared at home for the reason that the canning is done where the fruit is easily obtainable in its freshest and most perfect condition. When canned fruit is as reasonable in cost as it is at present, the housekeeper should certainly be very sure that her time cannot be used to better advantage before she undertakes to prepare quantities of fruit at home.
Perhaps no article of diet has increased in use during the last few years so rapidly as fruits. Not only the most hardy, but the more perishable varieties, including berries, are by improved methods of transportation, by the use of refrigerator cars and by increased areas of cultivation made available through a longer season, and at greater distances from the source of supply than ever before. The fruit industries, including the cultivation of the fruit, the great canning and drying establishments, and the transportation of the product, have become of immense importance in the commercial world.