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.