xic in
character, but merely irritating. However, the irritation arising from
excessive fermentation in the stomach may lead to gastric disturbances
of a more or less serious nature; hence the amount of carbohydrate
taken under certain conditions must be adjusted carefully.

~The Effect of Heat upon Carbohydrates.~--The changes wrought in the
carbohydrates as a result of heat have already been discussed to a
certain extent. It is seen that the sucrose (cane sugar) is soluble
alike in hot and cold water; the same is true of maltose; but lactose
is much more soluble in hot water than it is in water which has not
been heated. So far as their digestibility is concerned, the
application of heat (boiling) neither increases nor decreases the
utilization of these sugars by the body.

With starch it is an entirely different matter. It has been found that
the application of heat, either as dry heat, or in the presence of
moisture, brings about a definite change in the character of the
foodstuff. Pure starch admixed with water and boiled, passes into a
condition of colloidal dispersion, or semi-solution, known as starch
paste (Sherman). This is graphically illustrated in the cooking of
potatoes, in which the starch and water are mixed in nature; and in
the cooking of cereals and like starchy foods, to which water is added
in preparation for their cooking. In both cases the application of
heat adds greatly to the digestibility of the raw material by reason
of the change which is wrought in these substances, causing them to be
more readily acted upon by enzymes in the digestive juices.

This solubility of carbohydrates in hot water may be utilized in the
washing of utensils in which these substances have been prepared; thus
saving much time and effort on the part of the nurse in either the
diet kitchen or in the home.

FATS

The second member of the organic food group, and one which is almost
as widely distributed throughout animal and vegetable life as the
carbohydrates, is found in the fats. This foodstuff, while composed of
the same chemical elements that go to make up the carbohydrates,
contains these elements in different proportions; that is, fats
contain less oxygen and more hydrogen than carbohydrates.

~Typical Fats.~--The fats (as already shown in the Table on page 5)
are derived from both animal and plant life, but, like the
carbohydrates, do not always occur in the same form. Those of animal
origin include: