Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIP~ION
IMITATION SOUR CREAM PRODUCT AND
METElOD FOR MAKING SAME
Background of the Invention
Field of the Invention
The present invention relates generally to a
method for making a sour cream type product having
the appearance, taste, consistency and texture of
sour cream and, more specifically, to a method for
making an imitation sour cream product which may be
carried out in significantly less time than previously
known methods and results in a sour cream type product
significantly lower in at and calories than with
previously known methods.
Description of the Prior Art
Commercial sour cream, which is a popular ingre-
dient in salad dressings, dips, Eillings and like
food products, is typically prepared by innoculating
pasteurized, homogenized cream having a fat content
of about 18% by weight with one or more strains of
a lactic acid producing bacterial culture, ripening
the cultured cream for about 14 hours at about 70F.,
and cooling and packaging the resulting product.
Although this method results in a highly acceptable
product with a pleasing taste, sour cream prepared
- according to this method is high in both fat and cal-
ories; hence, those who must restrict their intake
of fat and/or calories must either severely limit
or cease altogether their intake of sour cream and
sour cream - containing products. Imitation sour
cream products which contain no dairy butterfat are
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disclosed, for example, in United States Patent No. -
Re. 27,381. However, these products contain other
fats and oils, usually at a level of from 8% to 25%
by weight of the product, and therefore are not suf-
ficiently low in either calories or fat.
Another drawback to the conventional method of
making sour cream lies in the amount of time required
for incubation of the bacterial cultures which produce
the lactic acid responsible for the characteristic
cultured taste in the finished sour cream product.
Efforts have been made to circumvent this time con-
suming process by the direct acid method which in-
volves adding acid directly to the cream or other
equivalent dairy or non-dairy starting materials.
Exemplary direct acid methods are disclosed in
United States Patents Nos. 3,355,298; 3,359,116;
3,378,375; 3,432,306; 3,506,663; 3,726,690 and
Re. 27,381. The majority of these processes,
however, either take several hours of processing time
or result in a product with a hiqher fat content than
desirable or both. In some, add:itional chemical
- additives or processing stages are required to even
approach a high quality sour cream type product such
as is made by biological fermentation. For example,
United States Patent No. 3,359,116 discloses a low
calorie sour cream product produced by replacing the
butterfat in the milk base starting material with
at least 0.5~ and up to 25% by weight of a lipoid
substance and incorporating a suitable monoglyceride
as an acid stabilizing and body building agent. By
way of further example, United States Patent No~ Re.
27,381 discloses a method for making an imitation
sour cream product which can be practiced in about
an hour, but which requires inclusion in the product
of 8~ to 25~ by weight of a suitable fat.
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United States Patent No. 3 r 235,387 to Stumbo
is illustrative of current methods for the production
of sour cream products which utilize acid-producing
bacterial cultures. Although the use of stabilizers
in these current methods results in an improved pro-
duct over that achieved by earlier methods using
bacterial cultures, processing time is still neces-
sarily quite lengthy since the cultured cream mixture
must be allowed to incubate for about 14 hours. In
addition, the resulting sour cream product is high
in both fat and calories, since the required starting
material is cream standardized to 18% to 25% by weight
fat. Pavey et al. disclose a method of making a low
fat, shelf stable biologically fermented sour cream
type product in United States Patent No. 3,969,534.
Although Pavey et al. uses a dairy base starting
material with a butterfat content of 0~ to 5% by
weight, the processing of this dairy material to
achieve the desired end product, requires considerable
time and involves a multiplicity of process steps.
For example, the dairy base starting material is
homogenized, pasteurized, cooled to incubation temp-
erature, innoculated with culture and allowed to stand
for about 4 hours, after which stabilizers are mixed
in and a second heating step is carried out for a
time sufficient to produce syneresis. The mixture
is ~t~en homogenized, flavors are added, the acidity
is adjusted and the final product is packaged and
specially processed to render it stable without re-
frigeration.
Summary of the Invention
It is, therefore, a~primary object of the presentinvention to provide a method for making a biologi-
cally fermented low fat imitation sour cream product
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which employs relatively few processing steps and
may be carried out in less time than heretofore known
methods of making biologically fermented sour cream
products.
It is another important object of the present
invention to proviae a dairy product based, biologi-
cally fermented sour cream type product which resem-
bles conventional sour cream in appearance, texture
and taste, but which has a fat content substantially
below that of conventional sour cream and existing
imitation sour cream products.
It is another object of the present invention
to provide a dairy product based, biologically fer-
mented sour cream type product which has the cultured
taste characteristic of conventional sour cream and
which has a fat content of not more than about 2
by weight.
Other objects and advantages will become apparent
from thè following description and amended claims.
In accordance with the aforesaid objectives,
the present invention provides a process for making
a low calorie, low fat sour cream type product resembl-
ing sour cream in appearance, texture and taste which
includes the steps of admixing one or more milk pro-
ducts selected so that the butterfat content in the
final product does not exceed 2% by weight and the
solids level does not exceed 20% by weight with at
least one stabili~er and heating the mixture in the
range from about 150 to 180F. (65.5 to 82.2C.),
preferably about 165 to 175F. (73.9 to 79.4C.),
- with constant agitation. Desirably, while the mixture
continues to be agitatedr other conventional ingre-
dien~ts intended to increase the product's shelf life
and improve its taste are added. Such additional
common ingredients may include preservatives, flavor-
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ings and the like. Bakers or cottage cheeese curd,-
which is the major constituent of the sour cream type
product prepared hereby and which, together with the
milk, comprises at least 98% by weight of the sour
cream type product, is added to the mixture and the
temperature of the mass is adjusted to and maintained
at not less than about 70 to 130F. (21.1 to 54.4C.),
preferably about 90 to 110F. t32.2 to 43.3C.).
Additional flavorings, particularly those which are
temperature sensitive, and suitable bacterial cultures
may be added once the mixture achieves the desired
70 to 130F. (21.1 to 54.4C.~, temperature range.
The resulting substantially uniform mixture is pumped
to a homogenizer where it is homogeniæed under conven-
tional elevated pressure conditions of 500 to 5000psig (35.15 to 351.5 kg/cm2), desirably 1000-2000
psig (70.03 to 140.06 kg/cm2) and preferably 1200
to 1500 psîg (84.36 to 105.45 kg/cm2). After homogeni-
zation, the sour cream product ;s packaged in a con-
ventional manner and refrigerated.
The sour cream type product of the present inven-
tion comprises a major amount of pasteurized, homo-
genized cultured low fat milk and minor amounts of
bacterial culture, flavorants, stabilizers and pre-
servatives. Most importantly, the product of thepresent invention has a total fat content by weight
of less than about 2~, preferably less than about
1.5% and most preferably about 0.5% to 1.0% fat, and
contributes only about 60 calories per serving (about
20 to 25 calories per ounce) to the diet. It is a
smooth, palatable product resembling sour cream in
appearance, texture and taste. Desirably, the product
- has a pH in the range 4.2 to 5.0, preferably 4.4 to
4.~ and a total solids content o~ about 16% to 20~,
35 optimally about 17%.
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~etailed Description of the Invention ~-
The present invention relates broadly to a dairy
product based, biologically fermented imitation sour
cream product which resembles sour cream in appear-
ance, texture and taste, but which has a fat contentwhich is substantially reduced below the fat content
of conventional sour cream. Hence, the imitation
sour cream ~ade by the process of the present inven-
tion is a desirable component of the diet of persons
wishing to decrease their caloric intake and to re-
duce the fat content of their diet. Moreover, the
method of the present invention, although it utilizes
bacterial cultures to achieve the cultured taste char-
acteristic of conventional sour cream, includes fewer
processing steps and requires far less time than pre-
viously known methods for making either conventional
or imitation sour cream and is, as a result, more
economical.
The process by which the unique imitation sour
cream product of the present invention is made in-
volves admixing low fat milk, at least one stabilizer
and flavorings at a temperature ranging from ahout
150 to 180F. ~65.5 to 82.2C.), preferably about
165 to 175F. (73.9 to 79.4C.), and adding ba~ers
2s cheese curd while adjusting the resulting temperature
to the range of about 70 to 130F. (21.1 to 54.4C.~,
preferably about 90 to 110F. (32.2 to 43.3C.).
In this 70 to 130F. (21.1 to 54.4C.) temperature
- range the temperature is high enough to prevent stabi-
lizers from setting, yet low enough that temperaturesensitive flavorants, such as those that are volatile,
acids, and bacterial cultures can be added without
deleterious effects on flavor and texture. Agitation
of the mixture is continuous throughout the process
so that after the addition of the cheese curd, culture
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and temperature sensitive flavorants, the final mix-
is substantially uniform and readily pumpable to a
homogenizer for high pressure homogenization.
In order to prepare an imitation sour cream
product having a fat content not greater than about
2% by weight, the fat contributing ingredientsr pri-
marily the milk, must be selected to achieve this
result. It should also be recognized that many dairy
flavorants which might be used can contribute to the
fat content of the final product. However, since
these flavorants are usually employed only in very
small guantities, their contribution to the final
fat content may not be significant.
The term "milk" as used herein means the con-
ventional mllk of commerce which may have a butterfatcontent ranging from as low as 0.1~ up to 7~ Within
this range are conventional skim milk (less than about
0.5% by weight butterfat) and conventional full fat
milk (up to about 3.5% by weight butterfat). Pre-
ferred for use in the process o~ the present invention,however, are milk products with a butterfat content
of less than about 2% by weight. The term "milk"
also contemplates combinations of various butterfat
content milks and equivalent compositions formed by
suitable admixtures of milk solids and water.
The major ingredient of the sour cream type
product of the present invention is bakers cheese
or small curd drained, uncreamed cottage cheese made
from skim milk. Preferably, bakers cheese with a
small curd to facilitate homogenization is employed.
These cheese ingredients generally comprise about
15% to 25% by weight non-fat milk solids and about
75~ to 85% water. When used hereinafter, the term
"bakers cheese" is intended to refer to either a
3S bakers cheese or cottage cheese curd product having
the foregoing characteristics. It will be appre-
ciated that various proportioned mixtures of milk
and bakers cheese can achieve a desired fat content
within the desired range of less than about 2% fat
by weight. However, it should also be recognized
that it is important to develop a suitable fluidity
in the mixture for ease of processing and, ultimately,
to develop the desired texture in the sour cream type
product. Therefore, the selection of milk and bakers
cheese proportions should take into account the im-
portance of maintaining a convenient moisture contentin the mixture during processing as well as the need
for achieving a particular fat content.
To prepare the imitation sour cream product of
the present inventionl the milk component is admixed
with a stabilizer and, if desired, salt, usually in
a stainless steel vat or like mixing container, and
heated to a temperature in the range 150 to 180F.
(65.5 to 82.2C.), preferably 165 to 175F. (73.9
to 79.4C.), for a time sufficient to achieve complete
blending of the ingredients and to effect pasteuri-
zation. The heating time and the temperature to which
the mixture is heated are inversely related with
increased temperatures requiring decreased heating
times. Experience has indicated that heating at about
175F. (79.4C.) for about 15 minutes is sufficient
to achieve the desired purpose. At lower temperatures
heating may continue for up to about one hour. Heat-
ing is typically indirect and is accomplished by pass-
ing pressurized steam through conduits which jacket
or are disposed within the mixing vat. Therefore,
relatively close temperature control can be maintained
by controlling steam flow through the conduits. Mix-
ing of the ingredients may be accomplished in any
desired fashion, e.g., by paddle blender agitation,
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use of recirculating pumps, or both.
It is preferred to use as the milk component
a mixture of 2% by weight butterfat milk and 0.5%
by weight butterfat milk. A desirable and useful
ratio of the various milks is about 3-4 parts by
weight of the ~ butterfat milk for each part by
weight of the 0.5% butterfat milk. Preferably, about
3.5 parts of the 2~ milk to 1 part of the 0.5% milk,
is employed in the initial admixture. However, the
process of the present invention contemplates the
use as starting materials of any combination of var-
ious butterfat content milks which, taking into ac-
count the bakers cheese content, will result in a
fat content in the Einal product within the prescribed
range. For example, milk with a butterfat content
of about 3% might be used in combination with non-
fat dry milk solids and water. However, in such
instances care must be taken to obsèrve the desired
solids level in the final product of 16% to 20~ by
weight. In addition, as previously indicated, it
is important to achieve a suitable fluidity in the
mixture to maintain ease of processing and, ultimately,
to develop the desired texture in the sour cream type
product.
The stabilizer or combination of stabilizers
employed may be selected from any of a number of com
mercially available dairy product stabilizer bases.
Typically useful stabilizers contain hydrocolloids
such as fruit pectin, pectic acid, alginic acid (as
well as suitable sodium and calcium compounds), tet-
rasodium pyrophosphate, agar-agar, carageenan, guar
meal or flour, carob-bean meal or flour, locust bean
gum, xanthan gum, enriched starches, and starch meal
or flour. Some of these stabilizers perform their
function more effectively in an acid mixturel such
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as is encountered in preparing the sour cream type-
pro~uct of the present invention. Care should be
taken, therefore, to select one of the more acid
stable stabilizers. Preferred stabilizers which have
been found to work well in the process of the present
invention are locust bean gum and xanthan gum.
To the heated and agitated mixture of milk and
stabilizer is added small curd bakers cheese in suf-
ficient quantity so that the bakers cheese curd com-
prises about 40 to 70% by weight, preferably about
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52 to 56% by weight, of the total ingredient mix,(excluding preservatives and flavorants). Agitation
of the mixture is continuous to allow the curd to
become substantially completely coated and intermin-
gled with the milk-stabilizer mixture which serves
as a dressing therefor. Since the bakers cheese curd
was likely to have been refrigerated at about 40F.
prior to use, the addition of the bakers cheese curd
will cause the overall temperature of the mixture
to decrease substantially. ThereEore, clos~ temp-
erature monitoring and control should be practiced
to maintain the mixture at a temperature not less
than 70 to 130F. (21.1 to 54.4C.), preferably 90
to 110F. (32.2 to 43.3C.). If the temperature drops
below aboùt 70F. (21.1C.), the stabilizer will begin
to set, resulting in destruction of the desired tex-
ture. Moreover, bacterial cultures which are added
as flavorants do not function as effectively at temp-
eratures below about 70F. (21.1C.) and function
at reduced efficiency below about 90F. (32.2C.).
- At temperatures above 130F. (54.4C.), certain fla-
vorants may be volatilized and bacterial cultures
are likely to be killed.
Preservatives and flavorants may be added at
any point in the process, e.g., to the milk-stabilizer
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mixture prior to the addition of the bakers cheese -
curd or to the milk-stabilizer dressed curds, or to
both, depending upon the temperature sensitivity of
the additives and the convenience of addition. Thus,
it is desirable to add flavorants and preservatives
which will not be volatilized or rendered ineffective
by high temperatures directly to the milk-stabilizer
mixture since the heat, together with the continuous
agitation, facilitates their dissolution in the mix-
ture.
Any conventional, food grade, FDA approved pre-
servative may be employed to inhibit mold formation
and other deterioration and to increase shelf life. -
Typical of the desirable preservatives is potassium
soLbate, a well-known bacteriostat, antioxidant and
mold inhibitor. Other suitable preservatives, e.g.,
benzoate of soda, may also be used effectively. Typi-
cally, preservatives are employed in only trace quanti-
ties, e.g., about 0.1% by weight: of the total ingre-
dient mixture.
Likewise, any food grade, FDA approved flavor-
ant may be used to adjust the taste of the imitation
sour cream product. Inasmuch as flavoring is a very
sub~ective area, and since tastes differ so widely,
each producer of imitation sour cream will select
flavorants in a combination which is believed to ap-
proximate most closely tXe distinctive cultured taste
characteristic of conventional sour cream. It should
be noted that while there are no flavorants whose
use is indispensable to producing an acceptable pro-
duct, experience has suggested that the use of certain
flavorants facilitates the achievement of a product
which closely resembles conventional sour cream.
For example, the use of salt (sodium chloride) in
combination with concentrated dairy flavorings, which
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may be added to the mixture prior to the addition -
of the bakers cheese curd, has yielded good results.
Exemplary of such flavorants which may be desirable
for use are concentrated cultured dairy flavorings
comprising lipase modified butterfat products which
are rich in volatile, flavorful fatty acids. One
such product is commercially available from Dairyland
Food Laboratories under the trade designation "LBO
50". Flavorants are typically employed in quantities
ranging from trace amounts up to about 2% by weight
of the final ingredient mix.
When temperature sensitive flavorants are used,
they should not be added until the temperature of
thç milk-stabilizer dressed bakers cheese curd has
been reduced to the 70 to 130F. (21.1 to 54.4C.
range. Although acid is not usually a temperature
sensitive flavorant, it has been found that the ad-
dition of acid flavorants at too high a temperature
will prevent the formation of the desired texture
in the product of the present invention. Therefore,
it is preferred to add acids after reduction of the
temperature to the prescribed range. Any one or
combination of edible, food grade, FDA approved acids,
such as citric àcid, lactic acid, phosphoric acid
or acetic acid may be selected to enhance the taste
o~ the sour cream type product of the present inven-
tion. However, experience has shown that the use
of one of the aforementioned acids in combination
with a commercially available mixture of common dairy
acids, such as Sour Cream Acid #22 made by Stabilized
Products, Inc. facilitates the achievement of a char-
acteristic sour cream taste. Illustrative of other
- temperature-sensitive flavorants which may be used
to enhance the product of the present invention àre
starter distillate and diacetyl.
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Cultures of lactic acid producing bacteria, which
are used primarily to assure a rich, cultured cream
taste in the product of the present invention, may
be added only after the temperature of the milk-stabi-
lizer dressed cheese curd mixture has been reducedto the 70 to l30F. (21.1 to 54.4C.) range, pref-
erably to between about 90 and 110F. (32.2 to 43.3C.).
Exemplary of useful commerciaily available cultures
are those containing streptococcus diacetilactus,
although other lactic acid producing bacterial cul-
tures can be used successfully. The culture acts
- to impart a desired sour cream like flavor to the
product so long as temperatures are maintained above
about 50F. (10C.). Thus, the culture contributes
to product flavor throughout subsequent blending and
homogenization steps. Once the product has been re-
frigerated, however, further bacterial action effec-
tively ceases. By adding the bacterial culture at
this point in the process and allowing it to con-
tribute its flavor influence during subsequent pro-
cessing, it has been found that substantially the
same flavor benefit can be achieved as with prior
art multi-hour incubation processes without~the dis-
advantages inherent in lengthy incubation processes.
After all desired ingredients have been throughly
admixed, which generally requires about 15 minutes
of blending at temperatures maintained between about
70 and 130F. (21.1 to 54.4C.), a substantially
uniform and fluid mix is formed which can be directed,
preferably by pumping, to a conventional homogenizer
unit. In the unit the mixture is homogenized at
pressures in the general range of 500 to 5000 psig
(35.15 to 351.5 kg/cm2), desirably between 1000 and
2000 psig (70.03 to 140.06 kg/cm2) and preferably
between 1200 and 1500 psig (84.36 to 105.45 kg/cm2).
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The resulting product has a smooth, creamy ap~earance
and a texture and taste very closely approximating
- that of conventional sour cream. The homogenized
product is packaged in conventional manner for sour
cream and stored under refrigeration. The usual shelf
life of the sour cream type product of the invention
when stored at standard refrigeration temperatures
is about 60 days.
The following example illustrates the practice
of the present invention and is intended to exemplify
and not to limit in any respect the content and scope
thereof.
EXAMPLE
The following ingredients were mixed in the
amounts indicated in a stainless steel vat equipped
with an agitator:
milk (2% butterfat)1720.0 lbs, (774 kg)
skim milk (less than
0.5% butterfat)500.0 lbs. (225 kg)
stabilizer, cor.sisting
of locust bean gum22.5 lbs. (10.1 kg)
salt 15.0 lbs. (6.75 kg)
Mixing was carried out using paddle blenaers and a re-
circulating pump while the contents of the vat were
heated by pressurized steam in the vat jacket to
175F. (7~.4C.), After 15 minutes the pump was shut
down and only blender ag;tation continued. Steam
flow through the jackets was cut off and the contents
of the vat allowed to cool down. To the milk-stabi-
-, lizer-salt mixture, the following preservative and
flavoring ingredients were added in the amounts noted:
potassium, sorbate 5.0 lbs. (2.25 kg)
Dairyland Food Labs "LBO 50n
flavoring 40.0 lbs. (18 kgj
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The mixture was constantly agitated during addition
of the above ingredients. Temperature was monitored
to assure that the temperature of the mixture remained
above 90F. (32.2C.). 2,675 pounds (1203.75 kg)
of refrigerated (40F.) (4.4C.) small curd bakers
cheese was then stirred into the already admixed
ingredients. Steam flow through the jackets was
resumed to maintain the temperature at about 90 to
95F. (32.2 to 35C.). Agitation was continued to
permit the bakers cheese curd to become intimately
intermingled and coated with the milk-stabilizer-
flavored dressing. The following ingredients were
then added in the amounts indicated: -
citric acid7.5 lbs. (3.37 kg)
Stabilized Products, Inc.
Sour Cream Acid ~2215.0 lbs. (6.75 kg)
Starter Distillate6.5 oz. (.18 kg)
Streptococcus diacetilactus
culture 10.0 oz. (.28 kg)
Blending was continued for at least an additional
15 minutes to assure formation of a uniform, fluid,
readily pumpable mix. The resuLting mixture was
pumped to a homogenizer where it was homogenizéd at
between 1200 psig and 1500 psig (84.36 to 105~45
kg/cm2) before being packaged and refrigerated. The
final product resembled sour cream in color, appear-
ance, texture and taste, contained about 1.0~ fat,
about 17% solids and had a pH of about 4.6. The
imitation sour cream product contained 9 grams of
protein, 3 grams of carbohydrate, l gram of fat and
60 calories in each 1/3 cup sized serving.
While the present invention has been described
with reference to specific embodiments thereof, it
will be understood that numerous modifications may
be made by those skilled in the art without actually
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departing from the scope of the claimed invention.
Accordingly, all modifications and equivalents may
be resorted to which fall within the scope of the
invention as claimed.
