in addition to fat, casein and appreciable
amounts of mineral matter. The composition varies with the character of
the milk from which the cheese was made. Average milk produces cheese
containing a larger amount of fat than proteids, while cheese from
skimmed or partially skimmed milk is proportionally poorer in fat.
Ordinarily there is about 35 per cent of water, 33 per cent of fat, and
27 per cent of casein, and albumin or milk proteids, the remainder being
ash, salt, milk sugar, and lactic acid. Cheese is characterized by its
large percentage of both fat and protein, and has high food value. It
contains more fat and protein than any of the meats; in fact, there are
but few foods which have such liberal amounts of these nutrients as
cheese.

The odor and flavor of cheese are due to workings of bacteria which
result in the production of aromatic compounds. The purity and condition
of the milk, as well as the method of manufacture and the kind of
ferment material used, determine largely the flavor and odor. Cheese is
generally allowed to undergo a ripening or curing process before it is
used as food. The changes resulting consist mainly in increased
solubility of the proteids, with the formation of a small amount of amid
and aromatic compounds.[42]

122. Digestibility.--Cheese is popularly considered an indigestible
food, but extended experiments show that it is quite completely
digested, although in the case of some individuals not easily digested.
In general, about 95 per cent of the fat and 92 per cent and more of the
protein is digested, depending upon the general composition of the
cheese and the digestive capacity of the individual. As far as total
digestibility is concerned, there appears to be but little difference
between green and well-cured cheese. So far as ease of digestion is
concerned, it is probable that some difference exists. There is also but
little difference in digestibility resulting from the way in which milk
is made into cheese, the nutrients of Roquefort, Swiss, Camembert, and
Cheddar being about equally digestible.[13] The differences in odor and
taste are due to variations in kind and amount of bacterial action. When
combined with other foods, cheese may exercise a beneficial influence
upon digestion in the same way as noted from the use of several foods in
a ration. No material differences were observed in digestibility when
cheese was used in small amounts, as for condimental purposes, or