IMPROVEMENTS IN PREPARATIONS OF MILK APPLICABLE FOR CHILDRENS' AND INVALIDS' USE AND IN THE MANU- FACTURE OF THE SAME
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
"
I WALTER HENRY THEW of Liverpool in the County of Lancaster do hereby
declare the nature of my said Invention for IMPROVEMENTS IN PREPARATIONS
OF MILK APPLICABLE FOR CHILDRENS' AND INVALIDS' USE AND IN THE MANU-
FACTURE OF THE SAME" to be as follows:-
Instead of directly condensing milk and preserving it by the addition of sugar
or by exposure of the milk to high temperatures I subject the milk in the first
place to a preliminary process of digestion by the aid of solutions containing the
active principles of the pancreas. I then raise the temperature of the milk
sufficiently to destroy the activity of the pacreatic ferments and subject the milk
to condensation.
The effect of the above named process of digestion as it is carried on by me is to
convert a portion of the casein and other proteid matters of the milk into so
called peptones which are bodies much moro readily absorbed by the alimentary
canal than the substances from which they are derived.
To the product of the above operation I give the name of condensed peptonized
milk. The peptonized milk in the event of its being desired to preserve it
indefinitely is before or during condensation treated with cane or other sugar as is
customary in the preparation of sweetened condensed milk or (if desired) it is
sterilized and preserved by being subjected for a sufficient time to a temperaturo
above 100 degrees centigrade or by successive heatings at lower temperatures.
When it is not required to preserve the condensed peptonized milk indefinitely
I prefere not to add to it considerable quantities of sugar but usually add sınall
quantities of pure milk sugar.
The following is the process which I adopt in the essential part of the operation.
The milk is heated in an open pan provided with rotary stirers to a temperature
varying between 40 degrees and 65 degrees centigrade though I prefer a tempera-
ture varying between 55 degrees and 60 degrees centigrade. Either before being
raised to this temperature or after, it is mixed with one third or one fourth of its
volume of water and the temperature of the mixture raised as above mentioned.
I then add to the warm dilute of milk bicarbonate of soda in the proportion of
120 grains to half an ounce to the gallon of the milk employed. I then add a
solution made either by the aid of water or spirit and water or glycerine from the

page_text: pancreas or pancreatic fluid taking care that the strength of the solution is such
that when a small quantity (any two ounces to the gallon of milk) is added to the
warm milk it will lead to the production of a slightly but perceptablo bitter taste
in a period varying between 15 and 30 minutes preferably in 20 minutes.
The production of a distinct bitter taste indicates that a portion of the casein
and other proteids of the milk are peptonized. I then heat the peptonized milk to
a temperature sufficient to destroy the added pancreatic ferments. Usually I heat
to 93 degrees centigrade or 95 degrees centigrade for 10 or 15 minutes. The
temperature is then allowed to fall to 70 degrees centigrade and the milk is then
condensed either in an open pan provided with revolving stirers to keep the milk
in motion or in a vacuum pan.
The product is improved in quality if the cream is separated by a rapid process
from the milk before it is peptonized and again added to the milk after the process
of peptonizing is completed.
Partially peptonized cows milk is of special use in the feeding of infants as in
addition to the fully digested proteid (peptone) present the casein which has not been
peptonized is in a condition which resembles very closely that in woman's milk.
I prepare a condensed peptonized milk for infant use by the following process:
The milk employed is of a composition known by previous analysis. I then
treat it with one third of its volume of water and peptonize it as has been already
described. I then add to it a quantity of cream sufficient to raise the amount of
butter to 35 per cent of the mixture and I then hent to 95 degrees centigrade for
10 minutes. I then add milk or cane sugar but preferably milk sugar in such
proportion as to raise the amount of sugar to between 5 and 6 per cent and
condense the product until it contains not more than 50 per cent of water.
The condensed product, which will keep for some days at a cool temperature
must be diluted so as to have the same volume as the original. milk after it has
been diluted with one third its volume of water.

page_text: B
I, WALTER HENRY THEW, of Liverpool, in the County of Lancaster, do hereby
declare the nature of my said invention for IMPROVEMENTS IN PREPARATIONS
OF MILK APPLICABLE FOR CHILDREN'S AND INVALIDS' USE AND IN THE MANU-
FACTURE OF THE SAME " and in what manner the same is to be performed, to bo
particularly described and ascertained in and by the following statement:-
The use of milk in which the proteids have been rendered more casy of digestion
by being converted in part at least into the bodies called peptones, has of late been
recommended by the medical profession, and has been employed with signal
advantage in cases of disease, and in the feeding of infants.
Hitherto such peptonized milk has been prepared immediately or shortly before
use by adding to the somewhat diluted and warmed milk, a solution of the
pancreatic ferments such as are now sold for this purpose, and allowing the process
to go on according to the directions affixed to or accompanying the preparation.
I believe that hitherto peptonized milk has never been condensed and subjected
to processes whereby it may either (a) bo preserved indefinitely, or (b) condensed
to such a degree as will allow of its being kept for a less period of time, or
(c) prepared so that the condensed peptonized milk has an approximately constant
composition such as is most favorable for the purpose of feeding infants.
When milk is peptonized by this method, it acquires a bitter taste, which if
pronounced, is exceedingly distasteful to many patients.
Completely peptonized milk prepared in the usual way is indeed so repulsive
that no one would think of administering it by the mouth. But besides the bitter
taste, ordinary peptonized milk possesses a property which has much tended to
render it unpopular; very shortly after it has been prepared, the butter separates
out, and floats in oily drops on the surface of the yellowish liquid which in
consequence has lost the characteristic and tempting appearance presented by
ordinary milk. Ordinary peptonized milk has a yellowish tint, and has lost the
characteristic opaque white appearance of natural milk. This feature of the
preparation added to the before mentioned separation of the butter fats in drops,
renders it distasteful to most persons and especially to invalids.
Now I have found that the bitter principle of peptonized milk can, by prolonged
heating, be in some measure eliminated so as to leave the milk not distasteful, also
that while the butter rapidly separates from ordinary peptonized milk so that it
has to be consumed immediately after it is prepared, the butter of the milk
prepared by my process does not separate in this way.
I have further found that by using phosphate of soda instead of bicarbonate of
soda, in peptonizing, the light colour of the milk is retained.
Lastly I have found much difficulty in boiling or condensing peptonized milk,
owing to the great liability to boil over. I therefore use for this purposo deeper
vacuum pans than those ordinarily employed for condensing milk. By this means
this trouble is avoided.
In carrying out my invention, I subject the milk in the first place to a
preliminary process of digestion by the aid of solutions containing the active
principles of the pancreas. I then raise the temperature of the milk to boiling
point so as to destroy the activity of the pancreatic ferments, and after the
addition of sugar condense the milk at a low temperature in vacuo.
The peptonized milk, in the event of its being desired to preserve it indefinitely,
is before or during condensation treated with cane sugar as is customary in the
preparation of sweetened condensed milk, or with maltose or other sugar, or, (if

page_text: desired) it is sterilized and preserved by being subjected after concentration and
sealing in tins for a sufficient time to a temperature above 110 degrees centigrade.
When it is not required to preserve the condensed peptonized milk indefinitely,
I prefer not to add to it considerable quantities of sugar, but usually add small
quantities of cane or milk sugar.
The following is the process which I adopt in the essential part of the
operation:-
The milk is heated in an open pan, provided with rotary stirrers, to a tem-
perature varying between 40 degrees and 65 degrees centigrade, though I prefer
a temperature varying between 55 degrees and 60 degrees centigrade, the stirrers
keep the milk in a state of continued motion.
Either before being raised to this temperature or after, it is mixed with one
third or one fourth of its volume of water, and the temperature of the mixture
raised as above mentioned.
I add to the warm diluted milk bicarbonate of soda, in the proportion of from
120 grains to half an ounce to the gallon of the milk employed or phosphate of
soda (Na, H PO 12 H₂ O) in the proportion of from half an ounce to one ounce to
the gallon of the milk employed. The object of this addition is to neutralize
any acid present in the milk (an acid reaction injuring the action) and to add a
very valuable constituent to the milk; also to prevent the coagulation of any
unpeptonized casein when the milk is subsequently heated.
After the addition of the bicarbonate of soda or of the phosphate of soda, I add
an-active-extract-of- pancreas, preferring a solution made either by the aid of water
or spirit and water, or glycerine from the pancreas, taking care that the strength of
the solution is such, that when a small quantity, say two ounces to the gallon of
milk, is added to the warm milk, it will lead to the production of a slightly but
perceptible bitter taste in a period varying between 15 and 30 minutes, preferably
in 20 minutes. The production of a distinct bitter taste indicates that a portion of
the casein andother proteids of the milk is peptonized. I then heat the peptonized
milk to a temperature sufficient to destroy the added pancreatic ferments and
any living germs of any kind which may be present in it. Usually I boil the
peptonized milk for ten or fifteen minutes, and then having added to the hot milk
the proportion of sugar which I consider desirable, subject it to the process of
concentration which is best carried out in a vacuum pan. The degree to which the
process of peptonizing is carried may be varied. When it is desired that nearly
the whole of the proteids of milk shall be converted into peptones, the process is
allowed to go on, before the ferment is destroyed until such time as acetic acid
produces either no precipitate in a small sample of the liquid, or but a very slight
precipitate.
Partially peptonized cow's milk is of special use in the feeding of infants, as in
addition to the fully digested proteid (peptone) present, the cascin which has not
been peptonized is in a condition which resembles very closely that in woman's
milk.
I prepare a condensed peptonized milk for infant's use by the following process.
The milk employed is of a composition known by previous analysis. I then
treat it with one third of its volume of water and peptonize it, as has been already
described. I then add to it a quantity of cream sufficient to raise the amount of
butter to 30 or 3-5 per cent of the mixture, and I then heat to about 90 degrees
centigrade for 10 minutes; I then add milk or other sugar, but preferably the
sugar obtained by the prolonged action of pancreatic extract upon pure starches in
such proportion as to raise the amount of sugar to between 5 and 6 per cent, and
slowly evaporate the product until it contains not more than 50 per cent of water.
This condensed product, which will if required keep for some days at a cool
temperature, must be diluted before using so as to have the same volume as the
original milk after it had been diluted with one third its volume of water. It may,
if desired, be sterilized and thus preserved by exposure to heat, in the way
previously described.

page_text: I am well aware that condensed milk has for long been known, and that
peptonized milk is also known as a preparation to be prepared as it is wanted for
use; but I do not believe that a condensed well peptonized yet palatable milk has
ever before been prepared in such a way that on dilution with the requisite amount
of water for use, the milk presents the characteristic opaque white appearance of
ordinary milk on which the butter fat does not rise in oily masses, or that such
milk has ever before been conveniently packed and preserved for an indefinite
period.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that
what I claim is :-
1st. As a new article of manufacture a condensed preserved milk, well peptonized
and yet palatable, in which the butter is in such a condition that on dilution with
water a peptonized milk is obtained having the white opaque appearance of
ordinary milk, and from which the fat is not liable to separate in floating masses
immediately after the milk is prepared for use, substantially as herein described.
2nd. The process of manufacturing peptonized milk which consists in henting
the milk to about 55 degrees centigrade, adding bicarbonate of soda or phosphato
of soda as set forth and pancreatic liquid to the milk in such proportions as herein
specified, heating sufficiently to destroy the ferment when the required amount of
conversion into peptones has been effected, and then condensing in deep pans
substantially as described.
3rd. The improvement in the process of manufacturing peptonized milk which
consists in keeping the milk in a state of continual motion by means of rotary
stirrers during the process of peptonizing and until the milk is introduced into the
vacuum pan whereby the butter is prevented from separating from the milk and
the bitter principle generated in the process is in great measure climinated.
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
Patent Agents for the Applicant.