f a
pound of digestible protein and from 0.4 to 0.6 of a pound of digestible
fat, which is about two thirds as much fat as is found in butter. Bacon
contains nearly as much digestible protein as other meats and from two
to three times as much fat, making it, at the same price per pound, a
cheaper food than other meats. In salt pork there is from 60 to 85 per
cent of fat, and less protein than in bacon. The protein and fat of pork
differ from those in beef not only in percentage amounts, but also in
the nature of the individual proteins and fats. The composition of pork
varies with the nature of the food that is consumed by the animal.
Experiments show that it is possible by judicious feeding in the early
stages of growth to produce pork with the maximum of lean meat and the
minimum of fat. After the animal has passed a certain period, it is not
possible by feeding to materially influence the percentage of nutrients
in the meat. The flavor, too, of pork, as of other meats, is dependent
largely upon the nature of the food the animal consumes. When there is a
scant amount of available protein in the ration, the meat is dry, nearly
tasteless, and contains less of the soluble nitrogenous compounds which
impart flavor and individuality.

133. Lard is prepared from the fat of swine, and is separated from
associated tissue by the action of heat. A large amount of fat is found
lining the back of the abdominal cavity, and this is known as leaf lard.
Slight differences are noticeable in the composition and quality of lard
made from different parts of the hog. Leaf lard is usually considered
the best. Lard is composed of the three fats, olein, stearin, and
palmatin, and has a number of characteristic physical properties, as
specific gravity, melting point, iodine absorption number, as well as
behavior with various reagents, and these enable the mixing of other
fats with lard to be readily detected. Lard is used in the preparation
of oleomargarine, and it is also combined with various vegetable oils,
as cotton-seed oil, in the making of imitation or compound lards.[46]
Lard substitutes differ little in general composition from pure lard,
except in the structure of the crystals and the percentage of the
various individual fats.

134. Texture and Toughness of Meats.--In discussing the texture of
meats, Professor Woods states:[45]

"Whether meats are tough or tender depends upon two things: the
character of the walls of th