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.

20. TABLE SHOWING COMPOSITION AND FOOD VALUE OF FRUITS.--Just as fruits
vary in their composition, so do they vary in their food value. This
fact is clearly shown in Table I, which gives the percentage of food
substances contained in different fruits and the food value per pound,
in calories, that these fruits contain. As in the table showing the
composition and food value of vegetables given in _Vegetables_, Part 1,
the figures in this table are taken from Atwater's Table of American
Food Materials and refer to the edible part of the material. Reference
to Table I, as progress is made with the study of fruits and their
preparation, will be of much assistance in learning the place that
fruits occupy in the dietary.


FOOD VALUE OF FRUITS

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