Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FIELD OF THE INVENTION
This inYentiOn relates to a process for preparing scrambled
eggs in a flexible, liquid impervious receptacle and to the receptacle
for preparing the eggs. Particularly, the invention relates to a
process of preparing scrambled eggs for commercial or institutional
feeding where it is desired to keep adequate supplies of food products
on hand which can be quickly prepared for serving.
BACKGROU~D OF THE INVE~TION
Commercial and institutional restaurants and cafeterias
typically purchase their eggs for scrambling in the shelled condition
by weight. The applicable health regulations and laws require that the
liquid, shelled eggs be pasteurized and then packaged at a temperature
below 40F. A common size of package for the liquid eggs is a 30 lb.
can and, for safe and extended storage, the shelled eggs must be frozen.
lS However, when the frozen eggs are thawed, they must be kept below 40F
during the thawing process in order to prevent spoilage and growth of
bacteria in the portion of the eggs which has thawed. Under these
conditions, a 30 lb. can takes approximately 3 days to thaw making it
necessary to always anticipate several days in advance the demand for
20 scrambled eggs. Therefore, it is one object of the present invention to
eliminate thls thawing out period and to provide frozen eggs in a
package whereby the frozen eggs can be immediately cooked.
- A notorious problem in cooking scrambled eggs is the tendency
o~ the eggs to ~tick and collect on the sldes o~ the pan or contain-~r In
which they are cooked. In a commercial or institutional kitchen 30
minutes or more may be re~uired to clean up the cooking vessels making
it necessary tG hire and keep on hand additional labor. Accordingly,
it is another object of the present invention to provide a method of
scrambling eggs which eliminates the problem of cleaning a cooking
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In addition to being a clean-up problem, the tendency of
scrambled eggs to adhere to the cooking vessel causes a loss of
the product and when large quantities are cooked this loss can
be substantial. AccordinglyJ it is another object of the present
invention to provide a method of cooking scrambled eggs so that
there is substantially no loss of the product.
During the relatively long thawing process the eggs will
likely become "off-flavor" due to prolonged contact with air
which takes place when the eggs are in a non-frozen condition.
Therefore, another object of the present invention is to provide
scrambled eggs which are cooked in the absence of air and which
have a superior flavor to those eggs prepared by prior art
methods.
In the prior art there are many packages for and methods
of freezing foods. In some of these the food is frozen raw or
after some measure of pre-cooking, placed in a pouch or bag, and
then frozen, after which the food may be removed from the pack-
age and cooked or it may be further cooked or warmed in the
package. Typical prior art patents are United States Patent No.
2,364,049 which issued on December 5, 1944 to Duryea Bensel;
United States Patent No. 2,902,396 which issued on September 1,
1959 to J, L. ~eynolds; United States Patent No. 3,567,468
which issued on March 2, 1971 to Donald Kitelay; and ~nited
States Patent No, 2,779,681 which issued on January 29, 1957 to
H. B. Sell et al. However, the prior art does not solve the
above listed problems which are attendant to methods for prepar-
ing scrambled eggs. The method for solving the listed problems
is described in the paragraphs below.
The present invention provides a process for preparing
cooked, scrambled eggs comprising the steps of:
(a) providing liquid, pasteurized fresh eggs;
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(b) providing an abuse resistant, flexible thermoplastic
receptacle;
(c) filling said receptacle with said liquid eggs, the
quantity of eggs placed in said receptacle being such that when
closed the receptacle will be flexible and can change shape and
that when lying on a flat, horizontal surface the receptacle will
be no thicker than approximately two inches;
(d) closing said receptacle so that there are no air
pockets within said receptacle;
(e) freezing the eggs within the receptacle within 24
hours after filling;
(f) storing the frozen eggs in the range between 0F and
-20F; and, subsequently,
(g) placing the receptacle containing the frozen eggs
in a liquid medium maintained at a minimum temperature of 160F;
(h) agitating the receptacle while in said medium to
flex the walls of said receptacle and prevent buildup of cooked
eggs on said walls; and
(i) continuing the agitation of said receptacle in said
medium for a period between 10 and 20 minutes whereby said eggs
are cooked in the absence of air.
Preferably, the liquid medium is a hot water ba~h main-
tained in the range of 160 to 212F. It is also preferable that
when the eggs are packaged they are packaged in a tubular, seam-
less thermoplastic casing and 3 to 10 lbs. of liquid eggs are
placed in each receptacle whereby a major dimension such as the
thickness of a receptacle is less than 2 inches. To achieve the
shortest cooking time and most acceptable results it is preferred
that the receptacle be agitated or tumbled in the hot water in
order to prevent solidification of cooked eggs on the receptacle
wall while the remainder of the eggs remain undercooked.
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A preferred material for the seamless tubular casing
is a thermoplastic laminate wherein the center layer is nylon
and the outer layers are cross-linked polyethylene. Metal clips
are the preferred means for closing each end of the tube but
heat seals could be employed.
The preferred process of the subject invention begins
by providing liquid eggs. These eggs are whole, fresh, raw
eggs which have been broken or shelled by machinery and by
techniques well known in the art. Subsequent to being shelled,
the liquid eggs are exposed briefly to an elevated temperature
medium to pasteurize them in order to comply with health regu-
lations. This pasteur~zation process does not cook the eggs
in any manner as the exposure time to the elevated temperature
is short and depends upon the pasteurization temperature selected,
e.g. about 2 seconds at 180F; about 3 minutes at 142F to
146F; etc, These times are sufficient to kill harmful bacteria.
Shelled eggs could, of course, be provided by manual breaking
but it is more economical to acquire the commercially broken eggs.
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After pasteurization, the eggs are cooled to a temperature
below 40F prior to being packaged in a receptacle. The preferred
receptacle is constructed from a tubular thermoplastic casing which is
closed by a metal clip at one end prior to filling and after filling is
closed at the other end by a second clip. The most satisfactory material
for the casing and one which will withstand the abuse of being frozen,
handled, transported, and heated in a medium while being agitated is a
tubing which is constructed from a laminate which has an interior layer
or layers of nylon and an outer layer or layers of polyethylene on each
side of the central nylon layer or layers. The polyethylene layers have
preferably been cross-linked by irradiation to a dosage level of at
least 6 megards. A typical casing will have a 10 inch lay flat width
and the total wall thickness of the casing will be of the order of 4 to
5 mils. Such a tubular casing is produced in a seamless manner by
coextruding the nylon and polyethylene layers from a coextrusion die
which technique i8 well known in the art. The polyethylene is preferably
a low density polyethylene having a density of about 0.92 grams/cc and
the nylon is preferably nylon 6. The inner polyethylene layer which
forms the inside walls of the casing will have a thickness of the order
20 of 1.0 to 1.5 mils., the nylon layer or layers will have a total thickness
of 1.25 to 1.75 mils. and the outer polyethylene layer or layers will
have a total thickness of about 1.0 to 1.5 mils.
After the casing has been clipped at one end and filled with
the liquid pasteurized eggs in a quantity which preferably ranges from
25 3 to 10 lbs. care is taken to ensure tha~ no air bubbles are lef t
within the package prior to closing the open end with a second clip.
These clips are deformable metal clips generally in the shape of a U
and are tightly bent around the gathered casing material to close each
end of the package in a liquid tight manner. Commercial clipping
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machines are available in the art from a number of manufacturers. Heat
sealing could also be employed but such seals are generally not as
reliable as clips.
The quantity of eggs placed within a given casing should be
such that a major dimension of the casing or package will not exceed 2
inches and is preferably about 1 1/2 inches after the casing or package
has been sealed or closed and is lying on a flat, horizontal surface.
For example, the length of the casing is selected so that when filled
and closed the thickness of the casing as it lies on a horizontal
; 10 surfacei will not be more than 2 inches. A thickness of this dimension
or less, and preferably about 1 1/2 inches, ensures that heat can be
- removed from the package quickly enough to ensure quick freezing and
that heat can be added to the package quickly enough so that the product
can be cooked substantially uniformly throughout without any overcooking
of the product at the package extremities. Furthermore, the receptacle
will be sufficiently flexible so that when tumbled in hot water for
cooking uniform product temperature is maintained so that buildup of
cooked eggs on the receptacle wall will be prevented.
After the receptacle has been filled with the fresh eggs and
20 closed it is then placed in a chilling medium, preferably less than 0F
80 that the eggs wlll be completely frozen ln less than 24 hours.
Relatively quick freezing is quite desirable as this eliminates any
possibility for bacteria to grow.
The eggs may be stored for an extended period of time while
25 frozen and there is no reason to suspect why any limitation should be
placed upon the storage life time as long as the eggs remain completely
frozen and the package does not develop any tears, pinholes, or leakage
so that air can reach ~he frozen product. To comply with health regulations
the eggs should be maintained at 0F or below, preferably in the
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range from 0F to -20F. However, storage below -40F is not preferred
as undesirable effects occur, such as the egg whites lose their ability
to be whipped.
When it is desired to prepare scrambled eggs, the package
containing the frozen eggs is placed in a cooking vessel containing
water in an initial range of 170F to 212F with the preferred tempera-
ture being about 185F. The water is maintained in the range of 160 to
212F with 175F being the most desirable temperature. While in the
water maintained at this temperature the product is agitated either
manually with a spoon or paddle or by tumbling the product in a revolving
cylinder resembling the tumbling of a front loading clothes dryer; or,
the product can be agitated by induced water currents in the vessel, the
currents being induced by pumps or propellers. The agitation should be
sufficient to flex the receptacle walls and change the shape of the
receptacle constantly so that the liquid eggs immediately adjacent the
walls are kept in motion and a mixing process throughout the receptacle
occurs. The eggs are then uniformly cooked and buildup of cooked egg on
the wall is prevented. Other heating mediums such as ethylene glycol, a
micro-wave oven, ultra-sonic energy or heated gas could be used but none
of these are as convenient and easy to use as hot water.
It has been found that by using induced water currents a 5 lb.
package of the frozen eggs can be cooked in 4 gals. of boiling water in
approximately 10 minute~. Also nine 10 lb. packages can be cooked in 40
gal~. o~ lB5~ water in approximately 18 minutes by tumbling the packages
in a revolving cylinder. In general, the cooking times run from 12 to
20 minutes for packages in the 3 to 10 lb. range.
After cooking, casings can be opened and mixed or chopped to
improve appearance if necessary and then placed in a serving pan.
Cooking the eggs in the absence of air provides the superior flavor that
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results from the method of the present invention. Oxidation or contact
with air while cooking has a deleterious effect and the flavor of eggs.
It has been surprisingly found that up to 50~ egg whites can
be substituted for whole eggs and a substantial savings realized as the
current price range of whole, shelled eggs is about 30¢ to 48¢ per pound
while egg whites run about lS~ to 25¢ per pound. The substitution is
quite acceptable both in taste and appearance and the usual and expected
loss in flavor and color does not occur. In fact, the addition of whites
can be said to be unnoticeable. In addition, pregelatinized corn starch
or other starch may be added up to one weight percent to minimize the
condition known as "weeping" when moisture is released from the eggs.
As a menu variation, vegtables, chopped meat, mushrooms, or the like can
be added to the egg mixture.
The receptacle material should, in general have the properties
of superior abuse resistance at temperatures from -40F to 212F,
resistance to flex cracking, suitability for closure by clipping,
resistance to delamination at temperatures of up to 212F, no shrinkage
at the cooking temperature, and superior resistance to impact and
puncture abuses.
An abuse resistant laminate such as the one disclosed herein
can be used in the form, fill, and seal process where a centerfolded
film is heat sealed on the remaining three sides to form a pouch. This
type of filling and sealing operation lends itself to high speed produc-
tion and would lower the packaging cost.
EXAMPLE
A total of 1,350 lbs. of pasteurized eggs were packaged in 140
casings of the preferred type described above and closed with metal
clips. The eggs within the packages were frozen within 24 hrs. and
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13 days after freezing were transferred to storage near an institutional
feeding kitchen. Four days later the casings were removed from storage
and the casings were placed in kettles having an initial temperature of
195F each, and nine casings were placed in each kettle. The water was
maintained at 175F during cooking and the casings were agitated with a
paddle. The casings were heated for 20 minutes then emptied and portioned
into serving pans. The serving pans were held at 160F for up to one
hour prior to service. The institutional feeder felt that the eggs had
better flavor and required about 50% less labor than required by their
prior method of preparing scrambled eggs. Of the 140 packages used in
th~s test only two defective casings were observed and the de~ect
appeared to be a puncture that somehow occurred to the casing during
handling.
EXAMPLE II
To determine the appropriate reheating times and cooking times
for the frozen eggs, packages having 10 lbs. each were prepared according
to the preferred method and were frozen at -40F. These packages were
subsequently placed in a 60 gal. steam jacketed kettle containing
approximately 40 gals. o 170F water. After 14 minutes, all of the
eggs were thawed and an additional five minutes were required to finish
the cooking. The temperature of the eggs ranged from 156F to 170~F
(internal) with the average tempera~ure being 159F. Agltation in the
kettle was provided by stirring the packages with a wooden paddle. The
product was not as untformly cooked as desired b~t mixing thc eggs af~er
removal from the package resulted in a product that was acceptable.
EXAMPLE III
A mixture of 75% whole eggs and 25% egg white was packaged
according to the preferred process in 10 lb. packages placed in a kettle
maintained at 180F. After five minutes an acceptably cooked product
was obtained. Simimlar products when placed in a 170F bath and cooked
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' 15 minutes were slightly overcooked. Eggs cooked in this manner had
more flavor and better color than eggs prepared by open kettle cooking.
The amount of moisture separation "weeping" observed in a finished
;~ product was greater than comparable kettle cooked scrambled eggs but: S this is not a problem where the eggs are served from steam table pans
with perforated liners.
Having thus described my invention I claim:
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