The Logan Republican. [volume] (Logan, Utah) 1902-1924, 1916-02-19


safer even the most carefully handled
and inspected milk is the conclusion
OF new professional paper OF the
department, in which are set forth
the most recent conclusions of scien
lists in regard to this matter. II
lseems probable. says this paper, tina,
within the next two years a large
proportion of the milk supply in the
large cities will be pasteurized
There is already a marked tendency
in this direction. About ten years
ago only per cent of the milk sup.
ply OF New York City was pasteuriz'
ed. In 1914, SO per cent was treat.
ed in this way. At the present time
80 per cent of the milk supply of
Boston is pasteurized, and there are
corresponding increases in many OF
the smaller cities.
Before the value Of pasteurization
as a hygienic measure was as well
recognized as it is today, 1t was prac.
ticed in secret by number of milk
| dealers as a means of preserving the
milk and preventing it from souring
Its commercial value in this respect
is undoubtedly great, but its chief
function Is the destruction Of disease
producing organisms. Proper pas
teurization should destroy about 90
per cent of all the bacteria in the
milk, although when the bacterial
count Of the raw milk Is low the re-
duction may be somewhat smaller.
The efficiency Of the process, it Is
pointed out, can not be based on the
percentage but rather on the charac
ter OF the bacteria destroyed.
The kinds Of bacteria that remain
alive after pasteurization depend on
the temperature to which the milk is
heated and the species of bacteria
which are in the raw milk. Three
processes of pasteurization, known
respectively as the fash process, the
holder process, and pasteurization In
the bottle, are now practiced in this
country. In the flash process the milk
, Is raised quickly to a temperature
OF about 100 degrees r. or more
held there for from thirty seconds tc
, a minute, and then cooled quickly
In the holder process the milk is
heated to temperature Of from
l40 degrees to $50 degrees F. and
held there for half an hour. When
pasteurization in bottles is practiced
the raw milk is put into bottles with
watertight seal caps which are i'm
mersed in hot water and held for
from 20 to 30 minutes at tempera
ture OF las degrees. In this way the
pasteurized milk is not subjected &c
any danger Of reinfection. On the
other hand, the seal caps must be
absolutely tight. and this involves IN
creased cost. In general, 1t may be
said that the holder process is com
ing into greater favor than either o
the others. This process permits O
the use OF lower temperatures, which
for various reasons, is highly desira
BILE. Another method OF pasteuriza
ton, or q rather modification o
the present holder process, Suggest
ed by the department investigators
is that OF bottling hot pasteurize'
milk. The process consists in pas
teurizing milk by the holder process
at las degrees F. for thirty minutes
then bottling II while hot In hot bot
ties steamed for two minutes imme
diately before filing. After filling
the bottles are capped and may d.
cooled by any OF the systems II
which the caps are protected. Th'
bottles are sprayed with water o
cooled by forced air circulation.
When milk is held at 145 degree
| F. for thirty minutes, all the diseas
producing bacteria, so far as can b.
ascertained, are completely destroy
ed. At the same time larger pei
centage of the bacteria that caus
milk to sour and smaller percent
age of those that cause 1t to rot ar
left than when higher Temperature
Is employed. Pasteurized at 10y
temperature, milk undergoes n
change which affects its nutritiv
value or its digestibility. Subsection
to a temperature OF $50 degrees +
or more, however. does result in Gel
tain chemical changes. Finally, pas
teurization at low temperatures l
more economical because the expens
es OF heating and cooling is less.
This, Of course, does not mea
that insufficient pasteurization shout
ever be tolerated. As a matter @
fact, the process OF pasteurization
frequently performed improperly. Fo
the holder process, 140 degrees f
Is the point at which investigation