WATER IN FRUIT

The juice of fruits that contain very little sugar and a large quantity of acid, such as the lemon, may be used for the seasoning of food in much the same way that vinegar is used. It may also be diluted with other liquids and used for a beverage.

Then, again, various kinds of fruit juices are subjected to a process of fermentation and, through the production of another acid, are made into vinegar and wines. When apples are treated in this way, the fermentation produces acetic acid and, in addition, a certain amount of alcohol.

It is on this principle that the making of wines depends.

WATER IN FRUIT.--The water content of fresh fruits is very high, reaching 94 per cent. in some varieties. Dried fruits, on the other hand, contain much less water, their content being in some cases as low as 15 to 20 per cent.

It naturally follows that the fruits low in water are high in food value, while those containing considerable water have in their composition less of the material that adds food value. The high percentage of water in fresh fruits, together with the acids they contain, accounts for the fact that these fruits are so refreshing.

Fruits of this kind, in addition to having this refreshing quality, help to provide the necessary liquid in the diet.

Just as fruits vary in their composition, so do they vary in their food value. 21. EFFECT OF RIPENESS ON FRUITS. --There is a very marked difference between ripe and green fruits as to their composition, flavor, texture, palatability, and digestibility. Green fruits, containing more acid than ripe ones, serve some purposes for which ripe fruits of the same variety cannot be used so well.

For instance, a very much better jelly can be made from grapes that are not entirely ripe than from those which have completely ripened. Green fruits contain less sugar than do ripe ones, and so they are more sour to the taste.

In some cases, the carbohydrate found in green fruits is partly in the form of starch, which in the process of development is changed to sugar. The cellulose of green fruits, especially that distributed throughout the pulp of the fruit itself, is usually tougher and harder than that which is found in the same fruit after it has ripened.

DIGESTIBILITY OF FRUITS.--The ripeness and freshness of fruits determine their digestibility to a great extent, but the peculiarities of each person have much to do with this matter.

Many times a particular fruit will agree with almost every one but a few exceptional persons, and, for no apparent reason except their own peculiarities of digestion, it disagrees very badly with them. Abnormal conditions of the alimentary tract, however, cannot be taken into consideration in a general discussion on the digestibility of foods, for it is a subject that cannot be treated except from a dietetic standpoint.

A safe rule to follow when a fruit is found to disagree with a person is to omit it from that person's diet. This need not prove a hardship, for the wide range, or variety, of fruits makes it possible to find one or more kinds that will agree with each person.