Note: Descriptions are shown in the official language in which they were submitted.
7~
LOW CHOLESTEROL EGG P~ODIJCT
This invention relates t~ a low cholesterol,
low fat liquid egg product. More particularly, this
invention relates to a low cholesterol, low fat liquid
egg product comprised essentially of egg yolk and egg
white, and having a color which is substantially the
same as scrambled fresh whole eggs.
In view of the emphasis which the medical
community is now placing on the importance of adopting
diets low in cholesterol and saturated fats, many people
are restricting their intake of eggs, or eliminating
their use entirely. However, it is widely known that
eggs have exceptional nutritional value, being an
excellent source of protein. As a result, there have
been many efforts to produce a liquid egg product which
has the nutritional value of whole eggs without the high
levels of cholesterol and saturated fat normally
associated therewith. In fresh whole eggs, the
saturated fat and cholesterol are concentrated in the
yolk, while the protein is found in both the egg white
and egg yolk. Therefore, most of the efforts to produce
a low cholesterol, low fat liquid egg product have been
directed at lowering or eliminating the egg yolk content
of the product while at the same time maintaining or
increasing the egg white content. To compensate for
these changes, most prior art products include non-egg
ingredients in their formulations. The effect of all of
these alterations, however, is to cause the functional
and organoleptic properties of the liquid egg product to
differ significantly from the properties of ordinary
whole eggs. One particular problem is that as the egg
yolks provide substantially all of the color to a liquid
whole egg product, a reduction in the level of egg yolk
causes the liquid egg product to have a pale, milky
color unacceptable to consumers.
Previous low cholesterol, low fat liquid egg
products having reduced egg yolk contents have addressed
this problem by incorporating natural or artificial
5~7
--2--
colorants into the formulations. Thus, in U.S. Patent
No. 3,475,180 to Jones, U.S. Patent Nos. 3,843,811
and 4,200,663 to Seeley et al. and U.S. Patent
No. 4,296,134 to Boldt, one or more certified U.S.
coloring agents are added to the blend in order to make
the color of the product more appealing. Additionally,
in U.S. Patent Nos. 3,840,683 and 3,911,144 to Strong et
al., beta-carotene and an extract of plant xanthophylls
were combined in suitable proportions to impart to the
liquid egg product the characteristic color of whole
eggs.
The addition of colorants in these low
cholesterol, low fat liquid egg products has not met
with consumer approval, in particular where the colorant
is artificial in nature. Thus, the addition of
colorants not only negatively effects other organoleptic
properties of the product, but consumers perceive the
addition of colorants as being ~unhealthyn.
Thus, the need exists for a low cholesterol,
low fat liquid egg product which does not contain high
levels of non-egg ingredients. Specifically, there is a
need for a low cholesterol, low fat liquid egg product
having the characteristic color of scrambled whole eggs
which does not contain non-egg colorants. The present
invention addresses these needs.
~ ne aspect of the present invention provides a
low fat, low cholesterol egg product comprising a
mixture including at least 90 wt.% egg white, and egg
yolk, the mixture having a color which is essentially
the same as the color of scrambled fresh whole eggs,
wherein the color is provided substantially by the egg
yolk. Desirably, the mixture includes at least 5 wt.%
of egg yol~.
In accordance with one embodiment of this
aspect of the present invention, the egg product further
includes very small amounts of non-egg ingredients.
Desirably, the non-egg ingredients are naturally
occurring constituents including a stabilizing agent to
~ '7
stabilize the cooked color of the mixture and/or a
thickening agent for increasing the viscosity of the
mixture when in a liquid state. Preferably, selected
stabilizing agents are added in amounts up to
about 1 wt.% of the mixture, and more preferably in
amounts up to about 0.02 wt.% of the mixture. Preferred
thicXening agents are desirably added in amounts up to
about 0.50 wt.% of the mixture; amounts between
about 0.005 wt.% and about 0.02 wt.% being more
desirable.
The low fat, low cholesterol egg product
according to this aspect of the present invention is
preferably produced in accordance with the following
process. Liquid egg yolk having a naturally intense
yellow color is combined with liquid egg white to form a
substantially homogeneous mixture including the liquid
egg yolk and at least 90 wt.% of the liquid egg white to
provide a mixture having a color essentially identical
to the color of scrambled whole eggs. Preferably, at
least 5 wt.% of the liquid egg yolk is combined with the
liquid egg white. The liquid egg yolk in accordance
with this aspect of the invention desirably has an NEPA
value of at least 4.0, and more desirably an NEPA value
of about 4.0 to about 4.2, to yield a mixture having a
color value of about 8 ppm to about 10 ppm of
beta-carotene equivalent.
The yolks in fresh whole eggs typically vary
in color from a light yellow color to a deep
orange-yellow color. This variation in color is due not
only to differences in the breed of the hens, but is
also due to variations in their feed. For instance, it
has long been known that hens can be manipulated to
produce eggs having a desired yolk color by feeding them
a diet rich in ingredients which produce that color.
One process according to the present invention
utilizes fresh whole eggs with yolks that have an
intense yellow color. In order to obtain eggs having
this characteristic, hens are fed a diet rich in
5~t7
-4
ingredients which produce a yellow coloring. Examples
of such ingredients include dried marigold extract,
yellow corn, alfalfa meal and other xanthophyll
containing materials. Hens maintained on such a diet
will naturally produce eggs which have yolks that are an
intense yellow color.
The color value of egg yolks is determined by
reference to a standard developed by the National Egg
Producers Association. Under that standard, egg yolks
are assigned an NEPA number, the lower the number the
paler the yellow color of the egg yolk and, conversely,
the higher the number the more intense the yellow color.
Generally, normal egg yolks have an NEPA value of
between about 0.8 and about 1.2, typically about 1Ø
NIntensely colored yolksn, as used in the present
description, have an NEPA value of 4.0 or higher,
preferably about 4.0 to about 4.2. NEPA values may be
determined by utilizing conversion information provided
in an article by Lee Campbell, Margaret Lally and
R. Forsythe, and appearing in Poultry Processina and
Marketing, May, 1960. Thus, egg yolks having an NEPA
value of 4.0 have a corresponding beta-carotene
equivalent value of 88 ppm, while egg yolks having an
NEPA value of 4.2 have a corresponding beta-carotene
value of 9~ ppm. (An NEPA value of 4.1 corresponds to
a 90 ppm beta-carotene equivalent.) The procedures for
determining beta-carotene equivalent values for liquid
egg products as established by the AOAC may be found in
procedure numbers 17.002, 17.003, 17.004 and 17.005 as
set forth in the Official Methods of Analysis of the
Association of Official Analytical Chemists, (14th Ed.
1984, p. 320). These procedures basically require the
spectrophotometric comparison of acetone extracts from
the liquid egg product with a standardized curve
produced from varying concentrations of b~ta-carotene.
Eggs having intensely colored yolks are
combined with egg white to form a mixture. Desirably,
the mixture constitutes between about 5 wt% and about 10
~5J(~
wt~ egg yolk and between about 90 wt% and about 95 wt%
egg white. The mixture may be prepared by combining
only the intensely colored yolks of whole eggs with egg
white in the proportions set forth above. Preferably,
however, the mixture is formed by combining whole eggs
having intensely colored yolks with additional amounts
of egg white. The whole eggs desirably constitute
between about 10 wt% and about 20 wt% of the mixture,
and more desirably, about 15 wt% of the mixture.
lo Consequently, the mixture desirably contains between
about 80 wt% and about 90 wt% egg whi~e in addition to
the egg white provided by the whole eggs.
After the egg whites have been combined with
either the whole eggs or egg yolks to form a mixture,
non-egg ingredients may optionally be added in order to
provide particular characteristics to the liquid egg
product as desired. The addition of any non-egg
ingredients is in such small quantities as to not
noticeably affect the color of the liquid egg product.
Cooked egg products typically evidence a
change in color upon standing for extended periods of
time. Therefore, the mixture preferably has added
thereto a non-egg ingredient which will act as a color
stabilizing agent to stabilize the cooked color of the
egg product produced from the mixture. Typically, the
stabilizing agent will consist of a weak acid, such as
citric acid, acetic acid, lactic acid, malic acid,
propionic acid, succinic acid, monosodium phosphate,
disodium EDTA or combinations thereof. Preferably, the
stabilizing agent is added in amounts of about 1% or
less of the weight of the mixture. More preferably, the
stabilizing agent is added in amounts up to
about 0.2 wt.% of the mixture; about 0.1 wt.%
stabilizing agent being most preferred. Typically, the
mixture without the stabilizing agent additions has a pH
of about 8.5. Upon the addition of the weak acid
stabilizing agent, the mixture will preferably have a pH
of between about 6.5 and about 6.8.
~&CP~r~;~ 7
Thickening agents may optionally be added to
the mixture. The thickening agents not only act to
increase the viscosity of the liquid egg product, but
also serve to improve the texture of the cooked product
and aid in releasing the cooked product from the heated
cooking surface. Preferred thickening agents include
xanthan gum, guar gum, gum agar, carageenan, methyl
cellulose and carboxymethyl cellulose. The total weight
of the thickening agent is desirably about 0.50% or less
of the weight of the mixture. Additions of between
about 0.005 wt.% and about 0.02 wt.% are more desirable,
with additions of about 0.01 wt.~ most desirable.
Other non-egg ingredients may be added to the
mixture as desired. For example, should it be desired
to increase the protein content of the liquid egg
product one or more non-egg protein replacements may be
added. Preferred protein replacements include soy
protein, sodium caseinate, whey protein and dry non-fat
milk solids. Preferably, the protein replacement is
added in amounts of up to about 10% of the weight of the
mixture. When dry non-fat milk solids are used as the
protein replacement, additions of about 2 wt.% to
about 5 wt.% are preferred.
Typically, after the egg whites have been
combined with either the whole eggs or egg yolks, a
substantially homogeneous mixture is formed in
accordance with homogenization techniques generally
known in the art. The non-egg ingredients may be added
to the mixture ~efore the mixture is homogenized, when
the mechanical steps used in homogenization will not
damage these materials so they are no longer useful for
their intended purpose. Thus, the homogenization
process serves to disperse the non-egg ingredients in
the mixture. Otherwise, they are added and dispersed in
the mixture after homogenization has been completed.
The mixture, including any non-egg
ingredients, may be directed to a pasteurizing apparatus
for pasteurization in accordance with procedures which
7~
are well known in the art. Pasteurization may take
place either before, during, or after the homogenization
step. Thus, the mixture may be pasteurized either
before or after the addition of any non-egg ingredients.
Following pasteurization, the egg product may be
packaged to exhibit an extended shelf life. The term
~extended shelf life~ i5 meant to reflect the fact that
the egg product produced in accordance with the present
invention will maintain its functional and organoleptic
properties for at least about four ~eeks without
spoiling. By way of example, the egg product may
achievP an extended shelf life in a frozen condition or
in a refrigerated condition, although other conditions
under which an extended shelf life may be achieved are
also contemplated. Using known pasteurization
procedures and packaging techniques which are well known
in the art, including aseptic packaging, the shelf life
of the product may be extended even further.
By substantially following the process as
described above, a low cholesterol, low fat liquid egg
product is formed. The liquid egg product desirably has
a color which is essentially the same as the
characteristic color of scrambled fresh whole eggs. In
this regard, the color of the liquid egg product is
determined by the AOAC method for determining
beta-carotene equivalent described above using
a 5.0 gm sample. Although 5.0 gm represents the sample
size to be used to determine the color of a liquid whole
egg specimen, the same sample size of the liquid egg
product of the present invention contains the
approximate color equivalent of whole eggs, even though
it contains significantly less egg yolk solids than
whole eggs. Generally, conventional scrambled fresh
whole eggs have a color value of about 8 ppm to
about 10 ppm of beta-carotene equivalent. By utilizing
fresh whole eggs with yolks having an NEPA value of
about 4.0 to about 4.2 in the amounts specified above,
the liquid egg product of the present invention will
8-
similarly have a color value of about ~ ppm to about 10
ppm of beta-carotene equivalent.
The following Examples illustrate certain
features of the invention as described above.
EXAMPLE I:
Intensely colored egg yolks are separated from
the egg whites of whole eggs produced by hens fed a diet
rich in ingredients which produce a yellow coloring.
Thus, the egg yolks utilized have an NEPA yellow value
of about 4.1, corresponding to a beta-carotene
equivalent of 90 ppm. By weight percentage, 10% of this
egg yolk is combined with 89.5% egg white and 0.5%
citric acid to form a mixture. The mixture is
pasteurized at 140F for a hold time of 3.7S minutes.
The liquid egg product formed according to
this Example has a pH of 6.5 and a solids content
of 15.04 wt.% which is less than the 24.2 - 24.7 wt.%
solids content of fresh whole eggs. More importantly,
however, this egg composition contains cholesterol in
amounts of merely 150 mg/100 g of sample which is
approximately 1/3 of the 400 - 450 mg cholesterol/100 g
of sample typically found in fresh whole eggs. In
addition, this egg composition has a fat content of only
about 2.7 wt.%, which is approximately
1/4 the 9.5 - 10 wt. % fat content generally found in
fresh whole eggs. This egg product when cooked has the
typical flavor of cooked scrambled fresh whole eggs and
a light texture.
EXAMPLE II:
A liquid egg product was formed from the whole
eggs from which the intensely colored yolks of Example I
were derived, along with an additional amount of egg
white. Thus, the yolks of the whole eg~s utilized in
this Example have an NEPA value of 4.1, which again
corresponds to a beta-carotene equivalent of 90 ppm. A
mixture is formed by combining 22.0 wt. % of these whole
eggs with 77.8 wt.% of egg white in addition to the egg
white provided by the whole eggs, and 0.2 wt.% of citric
75~ ,'
acid. The mixture is then pasteurized as in Example I.
The egg product produced in accordance with this Example
has a pH of 6.8, a solids content of 14.8 wt.%, a
cholesterol level of 136 mg/100 g of sample and a fat
content of 2.2 wt~%. When cooked, this egg product has
a light egg flavor and a puffy texture.
Although the invention herein has been
described with reference to particular embodiments, it
is to be understood that these embodiments are merely
illustrative of the principles and applications of the
present invention. It is therefore to be understood
that numerous modifications may be made to the
illustrative embodiments and that other arrangements may
be devised without departing from the spirit and scope
of the present invention as defined by the appended
claims.
