Improvements in the Treatment of Eggs.
Year: 1893

page_text: Date of Application, 19th Aug., 1893
Complete Specification Left, 19th June, 1894-Accepted, 28th July, 1894
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Eggs.
JOHN FORDRED of 37, Edgware Road, in the County of London, Technical
Chemist, do hereby declare the nature of this invention to be as follows:-
The object of this invention is the preparation of eggs, or, rather, the egg
contents, in such condition as will enable them to be kept a considerable time
without deterioration, and suitable for most of the purposes to which fresh eggs are
applied.
I have found that cane or beet sugar possesses a remarkable power of
preserving the entire contents of the egg, and of rendering the same miscible
with water and other fluids, even when the compound has been considerably
condensed. When so preserved, if stored in air-tight vessels, the compound is
available for use in the majority of cases where fresh eggs are now employed.
This special property appears to be possessed in a considerable degree by
other sugars, such as glucose, maltose, dextrose, and the like, and for some
purposes I make use of these sugars preferably to cane sugar.
A new white sugar possessing similar preservative properties has been recently
introduced into this market from the United States, under the name of "anhydrous
sugar," and is said to be manufactured from maize. It is a pure starch dextrose,
and has less sweetening power than the ordinary refined sugars of commerce.
This new sugar may also be used in combination with the ordinary refined sugars
of commerce. A similar kind of sugar is also manufactured in Germany, where
it is known under the name of crystalline grape sugar, and is used for brewing
purposes.
One mode of carrying my invention into practice is as follows:-
I take, say, 100 lbs. of the whole contents of fresh eggs, and having placed
them in an open pan, steam-jacketted, and provided with stirring apparatus, I
set this apparatus in motion, and introduce gradually into the pan, about
45 lbs. of granulated refined sugar. The effect of this introduction is seen in the
partial liquefaction of the egg which then takes place. Steam is then turned on,
the stirring continued, and the temperature carefully watched, until it reaches
165° F., or thereabouts, when the mixture of egg and sugar will have become quite
thin and limpid.
When it is desired to preserve the egg for any considerable length of time, the
temperature employed should not exceed 160° F. This temperature should be
maintained, with stirring, until the contents of the pan (the mixture of egg and
sugar) are brought to about the consistence of honey, the mixture should then 'be
conserved in air-tight vessels, for use when required.
The mixture of egg and sugar should not be reduced to dryness, as its flavour
would be injured, and its solubility seriously impaired, by such treatment.
By a similar inode of procedure, either the yolk of the egg, or the white
portion of the egg, may be treated alone.
In the case of the white of the egg, however, the temperature can be carried
higher, say to 180° F., or thereabouts, without risk of gelatinization, but when the
yolk of egg is treated alone, the temperature should not exceed 150° F., or
thereabouts, and in this case so much liquefaction does not occur.
I find that a very useful and valuable egg compound can be formed by adding

page_text: to the finished product above described, containing the whole contents of the egg,
an equal weight of the ordinary condensed milk of commerce.
These should be mixed together by the aid of a gentle heat, and preserved in
air-tight vessels.
Or, while manufacturing the condensed milk of commerce in vacuum pans, which,
in the finished state, generally contains about 50% sugar, my improved compound
may be produced by introducing the yolk, or the whole contents of the egg, into
the vacuum pan, towards the close of the evaporation of the milk, when the
sugar present has the. like effect in liquefying and preserving the egg as when used
alone.
In treating the yolk of egg, or the whole egg contents, with maltose sugar, I
make use of it in the form of malt extract, but in either of these cases, the
temperature should not exceed 150° F., or the diastasic action of the malt extract
would be impaired.
For some purposes, it is advisable to vary the proportions of the ingredients
above mentioned, and for this reason I do not confine myself to the quantities
named. Neither do 1 limit myself to the exact temperatures indicated..
Dated this 18th day of August 1893.
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Treatment of Eggs.
I JOHN FORDRED of 37 Edgware Road, in the County of London, Technical
Chemist, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :—
This invention relates to a novel method of treating eggs, whereby their contents
(the yolk and the white) may be preserved for a lengthened period of time in an
improved condition, and in such a state as to be immediately available for use in
the preparation of articles of food and drinks.
Many attempts have been made to preserve eggs whole, but up to the present
time, apparently without success; in some countries, the egg contents have been
reduced to dryness, but in this form the flavour is lost, the solubility is impaired,
and the material is apt to become mouldy.
It has also been proposed to use sugar as a preservative agent for the egg
contents, but in testing the means proposed for carrying out this process, I have
found that there are many disadvantages attaching to such treatment; thus, if the
finished compound be liquid, it will only keep sweet for a short time; again, if the
finished product takes the form of a solid, or semi-solid, it will have become, in a
great measure, insoluble, and, by keeping, loses color, and acquires a very
disagreeable flavour. A further, and possibly fatal, disadvantage, is, that the
product (in the solid or semi-solid state) is not homogeneous, or of uniform
consistence, and that the process of treatment is an exceedingly slow one, and
cannot be worked on a commercial scale.
Now, by my mode of treating eggs, I am enabled to produce a saccharine
compound practically homogeneous, and of uniform consistence, and readily miscible
with water and other fluids, even when considerably condensed. When so produced,
the compound is available for use in nearly all the cases where raw, untreated eggs
are now employed.
In order to preserve the egg contents in a satisfactory manner, and on a
commercial scale, it is necessary to get rid of a considerable portion of their normal

page_text: water, which is said to amount to about 75% by weight of the whole substance,
and that in a reasonable space of time. This I accomplish, as will be hereafter
more fully explained, by applying beat to the fluid matters under treatment whilst
in motion in a pan or other receiver, the presence of saccharine matter with the
egg contents enabling the temperature to be safely raised far above the setting
point of albumen, in addition to its powerful preservative influence.
This special property of saccharine matter appears to be possessed not only by
ordinary cane or beet sugar, but in varying degrees by glucose, dextrose, invert
sugar, milk sugar, malt sugar, and the like, and for some purposes I make use of
these sugars to replace cane sugar, wholly or in part.
I also employ a new white sugar of American origin, known as “anhydrous
sugar," and sometimes called crystalline grape sugar.
This sugar is a pure starch
dextrose, and has the advantage, for some purposes, of possessing less sweetening
power than the ordinary refined sugar of commerce.
In carrying my invention into practice, I proceed by preference as follows
I take, say, 1200 eggs, and having carefully removed the yolks and whites from the
shells, 1 well mix them together by the ordinary beating, or an equivalent process.
I then place 100 lbs. of the mixture in an open shallow pan fitted with a simple
stirring apparatus placed well below the surface of the liquid, and I slowly rotate
the stirrers, so as to keep the liquid in circulation. This shallow pan is fitted into
a water bath, the temperature of which should range from 160° to 170° F., so as to
maintain the contents of the pan at a temperature of about 145° F. Whilst the
stirring apparatus is in motion in the liquid, add about 50 lbs. of granulated
white cane or beet sugar, but gradually, so as to ensure a complete mixture and
prevent its aggregation, the heat and stirring being meanwhile continued. I thus
produce a partial liquefaction of the egg contents, which are at first opaque, but
gradually become thin and semi-transparent.
The stirring apparatus may consist of a vertical revolving shaft supported above
the pan, and carrying, at its lower end, two or more radial arms, which, when
rotated, keep the contents of the pan in constant motion. I find that good results
are obtained if the outer extremities of the radial arms travel at the rate of
about 80 feet per minute.
The main object of the stirring is to facilitate evaporation of a portion of the
water present in the egg mixture. This stirring should be carried on so as to
produce little or no froth, as this retards the evaporation of the water, but by
means of one or more stationary arms extending slightly below the surface of the
liquid, any froth or scum which may form is collected, and can be removed, and
thus a fresh surface is always presented to the atmosphere. The heat and stirring
I continue until the mixture has lost about 30% of its weight, which result (in
treating a depth of, say, three inches of the mixture) will require about five hours.
This continued heat and stirring for several hours I find produces a deep and rich
orange colour, and improves both the quality and the strength or viscosity of the
compound. It is then strained through a fine hair sieve, and when cold, should be
translucent, and of about the consistence of treacle, that is, just capable of being
poured from one vessel to another. It is then fit for immediate use, or for
storage.
When the condensed egg is required for export or otherwise, it should be stored
like honey, jams, and other confections, in closed vessels.
An open steam jacketted shallow pan, provided with a stirring apparatus, may
be used for treating the egg mixture, but in this case, the jacketing should be kept
at least one inch below the surface of the liquid to be treated, and during the
evaporation, the temperature of the egg and sugar should be carefully watched, to
prevent its rising above 145° F.
By a similar mode of procedure, either the yolk of the egg, or the white portion
of the egg, may be treated alone, and preserved for special uses.
It is to be noted, that when preserving egg contents with sugar, the proportion of

page_text: sugar used influences greatly the temperature to which the mixture can be safely
heated; for instance, when using it in the proportion indicated above, viz.,
50 lbs. of sugar to 100 lbs. egg contents, 145° F. is a safe temperature to be
employed when, however, a larger proportion of sugar is made use of, say, 66 lbs.
to 100 lbs. egg contents, the temperature may be safely carried to 165° F., which
temperature with a smaller quantity of sugar, say, 33 lbs. to 100 lbs., would
partially coagulate the albumen, and spoil the result.
;
My principal reason for employing the saccharine substances other than cane or
beet sugar, is because all those above mentioned possess less sweetening power than
cane or beet sugar, and this property is of considerable value, when preparing egg
compounds where less sweetness is required.
For example, the egg compound produced by the use of glucose sugar, is better
adapted for the production of omelettes, batter puddings, pancakes, and the like,
where much sweetness is objectionable.
Another reason for their employment is, that some of them are cheaper than
cane and beet sugar.
A third reason is, that some are obtainable in an uncrystallizable condition
(either liquid or solid).
The use of a liquid sugar allows the evaporation of the water to be carried
further than the point indicated, and the finished product may be semi-solid, and
yet easily soluble or miscible in water, and is better adapted for mixing with some
dry edible substances.
Again, the egg compound produced by the use of malt sugar, is of an entirely
different nature, being not only an article of food, but possessing medicinal
properties.
When employing malt sugar as a preservative agent for the eggs, I prefer to use
it in the form of malt extract of the ordinary consistence, and I find a good
result is obtained by using equal parts of these substances. These are heated
together at a temperature not exceeding 145° F., and kept constantly stirred, till
the compound is reduced to about the consistence of molasses or treacle, and as, in
this operation, the temperature does not exceed 145° F., the diastasic action of the
malt extract is not impaired.
I find that a very useful and valuable egg compound can be formed by combining
together milk and eggs in or about the proportion of 3 lbs. of raw egg and 2 lbs. of
condensed milk of commerce.
When preparing this compound, I prefer to use a vacuum pan provided with
stirrers, and whilst manufacturing the condensed milk (which, in the finished state
generally contains about 50 per cent. of sugar) to introduce, by suction, the beaten-up
yolk, or the whole contents of the egg, after straining, into the vacuum pan,
towards the close of the evaporation of the milk, when the sugar present will be
found to have the like effect in liquefying and preserving the egg, as when used
alone.
For some purposes, it is advisable to vary the proportion of the ingredients
above mentioned, and for this reason, I do not confine myself to the quantities
named, neither do I limit myself to the exact temperatures indicated, as I have
found that the gelatinizing or setting point of the albumen varies considerably in
different eggs; also in the white and yolk of the egg; but throughout this
Specification I have named 145° F. as a safe temperature to be used in carrying out
my invention.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is
1. The treatment of eggs, whether the whole contents, or the yolks or the
whites separately, so as to form a practically homogeneous, semi-fluid or semi-solid
product, in the manner and for the purposes above set forth.

page_text: 2. The manufacture, as marketable products, of the practically soluble and
homogeneous egg compounds above described, suitable for use in the preparation of
foods and nutritive drinks, or otherwise.
NEWTON & SON,
Agents for the Applicant.