oth to
remove any superficial dust which may be adhering to them. Every time
a portion of the milk is removed thereafter the tops should be again
cleansed before the milk is poured out. This is a wise precaution, and
often prevents contamination from the hands, etc.
The amount of water in milk prevents its being an adequate food for
adults except in certain pathological conditions. However, it
furnishes a supplementary food unequaled by any other beverage known.
There are fortunately only a few individuals who are unable to drink
milk. There are many who fancy they cannot do so, but if the nurse has
the ingenuity to utilize some of the various methods whereby milk is
made more digestible, it will generally be found that the patient can
take it without trouble. In cases of personal dislike, if the milk is
flavored or colored or made up into soup, cocoa, chocolate, junket,
custards, blanc-mange, etc., it will usually prove acceptable.
~Application of Heat.~--A word as to the changes which are brought
about as the result of heat as applied to milk. These changes are
demonstrated in the two methods commonly used in the preparation of
milk known as "pasteurization" and "sterilization." Pasteurization is
rather an indefinite term to use, unless the time and the temperature
to which the milk is subjected are given. According to Morse and
Talbot "the term sterilization should never be applied to the
processes used in the preparation of milk for the feeding of infants,
because the milk is never rendered bacteriologically sterile by
them."[31]
As a rule the flavor and odor of milk are not changed by heat until
the temperature reaches nearly to the boiling point. A scum then
forms on boiling milk, composed of casein 50.86%, fatty matter 45.42%,
ash 4.72% (Rosenau). Prolonged boiling changes the color of milk from
a creamy white to a yellowish brown which deepens with boiling. This
is due to the caramelization of the milk sugar. Cream will not rise
(or its rise will be very slow) on milk which has been subjected to a
temperature of 150 deg. F. for thirty minutes or more because the fat
droplets are broken down so that they cannot hold together at that
temperature and become more completely distributed throughout the
fluid.[32]
~Pasteurization~ is acknowledged to be preferable to sterilization in
milk used for infant feeding because the higher the temperature the
greater the change in the chemical composition of the fluid.
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