3. As far as the composition of fruits is concerned, it is such that most fresh fruits are not particularly high in food value. However, they are characterized by other qualities that make up for what they lack in this respect; then, too, what they contain in the way of heat-producing or tissue-building material is easily digestible. Most fruits contain considerable acid, and this food substance makes them stimulating to the appetite. Advantage of this fact is taken when fruits are served at the beginning of a breakfast or when several of them are combined in a fruit cocktail and served before luncheon or dinner. This acid produces real stimulation in the stomach, resulting in a flow of gastric juice from the glands of the stomach walls. In addition, the delightful color, the fragrant odor, or the pleasant taste of fruit, although a mental effect, is just as real and just as valuable as the actual stimulation of the acids.
4. Many fruits are eaten raw, while others are cooked either because they require cooking to make them appetizing or because it is desired not to use them in their raw state. The cooking of fruits has a variety of effects on them, being sometimes advantageous and other times detrimental. The flavor is always changed by the application of heat, and in some cases the acid that fruit contains becomes stronger. On the other hand, the fibrous material, or cellulose, of fruits is softened by cooking and thus becomes more digestible. Then, too, the sugar that is usually added to fruits in their cooking increases their food value. Because of these facts, cooked fruits have considerable value and, like raw fruits, should have an important place in the diet. Those fruits which are dried and usually eaten raw, such as figs and dates, supply much nourishment in an easily digestible form.
5. The medicinal value of fruit has long been considered to be of importance, but this may be almost entirely disregarded, for, with the exception of the fact that most fruits are valuable as a laxative, there is nothing to consider. However, several fruits, such as blackberries and bananas, have an anti-laxative effect, and large quantities of these should for the most part be avoided, especially in the feeding of children.
6. In general, fruits are divided into two classes, namely, food fruits and flavor fruits. As their names imply, food fruits are valuable as food, whereas flavor fruits are those distinguished by a characteristic flavor. It should be remembered that the flavors, as well as the odors, of fruits, are due chiefly to what is known as their volatile, or ethereal, oils. Fruits in which these oils are very strong are often irritating to certain persons and cause distress of some sort after eating.
7. In this Section, it is the purpose to acquaint the housewife with the relative value and uses of the various kinds of fruit, to teach her the best methods of preparation, and to supply her with recipes that will encourage her to make greater use of this valuable food in her family's diet. In this discussion, however, the general classification of fruits is not followed. Instead, the various fruits are arranged alphabetically under the headings Berries, Non-Tropical Fruits, Citrus Fruits, Tropical Fruits, Melons, and Dried Fruits, in order to simplify matters. While it is hardly possible to use fruits too extensively, they must not be allowed to take the place of other more nourishing foods that are required by the body. Therefore, in order to make proper use of them, their value in the diet should not be overlooked.
NATURE OF FRUITS
ADVANCE IN FRUIT CULTIVATION
8. It is sometimes difficult to distinguish between vegetables and fruits. For instance, the tomato is in reality a fruit, but it is commonly used as a vegetable, and rhubarb is more of a vegetable than a fruit, but it is always used as a fruit. It can therefore be seen that the line between vegetables and fruits is not clearly drawn. It is well to remember that fruit is usually the edible pulpy mass covering the seeds of various plants and trees, and that it is generally cooked or eaten raw with sugar, whereas vegetables are seldom sweetened in cooking.
9. Great strides have been made in the cultivation of fruit. Many varieties that formerly grew wild are now commonly cultivated. Most of the cultivated fruits are superior to the same kind in the wild state, at least in size and appearance, but often there seems to be a loss of flavor. Through cultivation, some fruits that were almost inedible in their wild state on account of containing so many seeds have been made seedless. Also, through cross-cultivation, varieties of fruit different from what formerly existed have been obtained. An example of such fruit is the loganberry which is a cross between a red raspberry and a blackberry and retains many of the qualities of each. However, some small fruits, such as blueberries, or huckleberries, are still grown wild and marketed only from their wild source.