U.S. patent application number 10/774328 was filed with the patent office on 2005-09-08 for calcium fortified dairy products.
Invention is credited to Johnson, Timothy T., Konkoly, Amy, Murphy, Maeve, Silva, Ellen M., Stoddard, Gary W..
Application Number | 20050196489 10/774328 |
Document ID | / |
Family ID | 24926870 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050196489 |
Kind Code |
A1 |
Murphy, Maeve ; et
al. |
September 8, 2005 |
Calcium fortified dairy products
Abstract
Nutritionally improved cultured dairy products such as yogurt
products include a fine powdered calcium phosphate salt of reduced
particle size having a mean diameter .ltoreq.6 .mu.m in amounts
sufficient to provide a total calcium content of 0.25% to 0.75%. A
method for producing the calcium fortified yogurt is also provided
wherein an fine powdered insoluble calcium salt is admixed with a
milk blend prior to fermentation. The yogurt is prepared by
conventional fermentation. Both stirred style and cup set style
yogurt products can be prepared.
Inventors: |
Murphy, Maeve; (Plymouth,
MN) ; Silva, Ellen M.; (Minnetonka, MN) ;
Stoddard, Gary W.; (New Brighton, MN) ; Konkoly,
Amy; (Minneapolis, MN) ; Johnson, Timothy T.;
(St. Anthony Village, MN) |
Correspondence
Address: |
GENERAL MILLS, INC.
Number One General Mills Blvd.
Minneapolis
MN
55426
US
|
Family ID: |
24926870 |
Appl. No.: |
10/774328 |
Filed: |
February 9, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10774328 |
Feb 9, 2004 |
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09728443 |
Dec 1, 2000 |
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6740344 |
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Current U.S.
Class: |
426/34 |
Current CPC
Class: |
A23C 9/1322
20130101 |
Class at
Publication: |
426/034 |
International
Class: |
A23C 009/12 |
Claims
1-29. (canceled)
30. A fermented dairy product fortified with calcium comprising: A.
a quantity of fermented dairy product having a viscosity of at
least 1500 cps (at 5.degree. C.), and B. sufficient amounts of
calcium phosphate, dispersed in the fermented dairy product to
provide at least 251 mg of calcium per 170 g (up to 1500 mg calcium
per 170 g) wherein the particle size of the calcium phosphate
comprises particles having a mean diameter of .ltoreq.6 .mu.m.
31. The fermented dairy product of claim 30 wherein the calcium
phosphate is calcium phosphate tribasic.
32. The fermented dairy product of claim 30 wherein the fermented
dairy product is yogurt.
33. The fermented dairy product of claim 30 wherein the dairy
product is free of a fruit ingredient.
34. The fermented dairy product of claim 30 wherein the total
calcium content is about 0.29 to 0.76% by weight.
35. The fermented diary product of claim 31 wherein the calcium
phosphate is evenly dispersed throughout the product.
36. The fermented dairy product of claim 30 wherein the pH of the
product is about 4.4 to 4.6.
37. The fermented dairy product of claim 30 additionally comprising
a high potency sweetener.
38. The fermented dairy product of claim 32 wherein the yogurt is a
stirred style yogurt product.
39. The fermented dairy product of claim 32 wherein the yogurt is a
cut set style yogurt product.
40-51. (canceled)
52. A calcium fortified milk based food product exhibiting improved
nutrition and good organoleptic properties, comprising: a
pasteurized milk base comprising at least one milk ingredient and
having a native calcium content, and sufficient amounts of
sufficient amounts of calcium phosphate in powder form comprising
particles having a mean diameter of .ltoreq.6 .mu.m to provide a
total calcium content of 125% to 500% of the native calcium
content.
53. The food product of claim 52 wherein the food product is a
fluid milk.
54. The food product of claim 53 wherein the fluid milk is
refrigerated milk.
55. The food product of claim 54 wherein the pasteurized milk base
comprises at least a mammalian milk ingredient.
56. The food product of claim 54 wherein the fluid milk is
chocolate flavored.
57. The food product of claim 53 wherein the fluid milk is UHT
milk.
58. The food product of claim 52 wherein the food product is a
cultured dairy product.
59. The food product of claim 58 wherein the cultured dairy product
is a yogurt.
60. The food product of claim 59 wherein the cultured dairy product
is a cheese.
61. The food product of claim 58 wherein the total calcium content
ranges from about 0.25% to about 0.75%.
62. The food product of claim 52 additionally comprising a
gelatinized starch.
63. The food product of claim 62 wherein the milk is chocolate
flavored.
64. The food product of claim 63 wherein the food product
additionally comprises a sweetener and is in the form of a
pudding.
65. The food product of claim 52 wherein the milk ingredient
includes a soybean milk.
66. The food product of claim 59 free of calcium carbonate.
67. The food product of claim 59 wherein the yogurt is a cup set
style yogurt.
68. The food product of claim 67 additionally comprising about 1%
to 15% of a fruit sauce.
69. The food product of claim 59 disposed within a sealed container
fabricated from a flexible film.
70. The food product of claim 59 disposed within a sealed container
fabricated from a flexible film in the form of a tube.
71. The fermented dairy product of claim 30 aerated to a density of
0.5 to 0.9 g/cc.
72. The fermented dairy product of claim 71 frozen to -15 to
-2.degree. C.
73. The food product of claim 53 wherein the fluid milk is
homogenized.
74. The food product of claim 53 further comprising at least one of
a stabilizer and thickener.
75. The food product of claim 74 wherein the at least one of the
stabilizer and thickener is selected from the group consisting of
starch, gelatin, pectin, agar and carrageenan.
76. A dairy product fortified with a fine powered calcium phosphate
comprising: a pasteurized milk base having a native calcium
content; and sufficient amounts of calcium phosphate in powder form
with particles having a mean diameter of .ltoreq.6 .mu.m to provide
a total calcium content of 125% of the native calcium content.
77. The dairy product of claim 76 wherein the milk base constitutes
homogenized milk.
78. The dairy product of claim 76 further comprising at least one
of a stabilizer and thickener.
79. The dairy product of claim 78 wherein the at least one of the
stabilizer and thickener is selected from the group consisting of
starch, gelatin, pectin, agar and carrageenan.
Description
FIELD OF THE INVENTION
[0001] This invention relates to food products, especially
refrigerated fermented dairy products such as yogurt that are
calcium fortified and to their methods of manufacture, and more
specifically to yogurt fortified with calcium.
BACKGROUND OF THE INVENTION
[0002] The present invention provides improvements to those calcium
fortified yogurt products and methods of preparation that are
described in U.S. Pat. No. 5,820,903 entitled "Calcium Fortified
Yogurt and Methods of Preparation" (issued Oct. 13, 1998 to Fluery
et al.) and which is incorporated herein by reference. The '903
patent describes the post fermentation addition of a calcium
phosphate having a particle size of less than 150 microns to
produce a calcium fortified stirred style yogurt. In important
part, the present improvement resides in selecting and adding a
more fine powder form of calcium phosphate having a particle size
of less than six microns to a milk base prior to fermentation. By
utilizing the more fine powder, it has been surprisingly found that
pre-fermentation addition can be practiced. As a result, methods
have now been found to produce either a stirred style yogurt
product or a cup set fermented yogurt product from the same or
similar calcium fortified milk base. Moreover, the process can be
simplified relative to the post fermentation addition to eliminate
the need for preparing a sterilized, pH adjusted calcium phosphate
slurry for post fermentation addition.
[0003] Recent medical studies have indicated that a diet containing
the U.S. recommended daily allowance ("RDA") of calcium can be
effective in preventing or mitigating osteoporosis, and also
possibly high blood pressure and colon cancer. There is therefore
great public interest in the consumption of food products that will
supply the recommended daily allowance of calcium.
[0004] Nutritionists and consumers alike recognize dairy products
as good sources of calcium. Consumers who may be most in need of an
adequate calcium intake (e.g., dieters, the pregnant or middle aged
women, and children) are target consumers for yogurt products.
[0005] An unfortified six ounce (170 g) serving of fruit-flavored
low fat yogurt provides only approximately 200 to 250 mg of calcium
(i.e., about 0.12% to about 0.15% calcium). The current RDA is 1000
mg. Thus, the natural calcium content of yogurt must be
supplemented by fortification with added calcium in order for a
single serving of yogurt to provide 100% or even 50% of the current
RDA for calcium. This problem is even more severe for yogurt
products containing up to about 20% fruit sauce since such fruit
materials are low in native calcium content.
[0006] Serious practical difficulties have been encountered in
incorporating supplemental calcium into dairy products because most
calcium salts have very low solubility in milk. Indeed, in milk
itself, up to 60 to 70% of the calcium exists as insoluble
colloidal calcium phosphate associated with the casein micelles.
Added calcium salts, being generally insoluble and not suspended by
casein, therefore tend to settle out, frustrating attempts to
maintain uniform dispersions during manufacture.
[0007] This problem of suspending insoluble calcium salts is
compounded by the fact that generally the yogurt base should not be
agitated during the incubation period, i.e., the yogurt should be
quiescently fermented. Thus, in the manufacture of yogurt using vat
incubation, the required lack of agitation during incubation can
cause a substantial portion of an insoluble calcium salt to settle
to the bottom of the vat. The salt then must be laboriously scraped
off the bottom of the vat and blended into the yogurt. In light of
these cleaning difficulties, this process is not only impractical
using conventional yogurt manufacturing equipment, but also is
likely to adversely affect the texture of the product. In the
production of cup set or in cup fermented yogurt products, the
fermentation step should also be quiescently fermented. Settling
can result in a product unacceptable to the consumer.
[0008] The prior art, however, includes a variety of efforts to
overcome the substantial problems of calcium fortification of
yogurt. One approach to the calcium fortification of yogurt is
disclosed in U.S. Pat. No. 5,449,523 (issued on Sep. 12, 1995 to
Hansen) entitled "Process For The Manufacture Of A Calcium
Fortified Yogurt With Improved Heat Stability." In this method, an
expensive soluble source of calcium is employed. Adding to the cost
of the '523 patent is that the calcium content of the already
expensive material is less than a third of the preferred salt,
tricalcium phosphate, used herein. Moreover, the methods employed
in the '523 patent require the addition of chelating agents to
avoid undesirable milk protein precipitation. Usage of such
required chelating, however, can adversely affect the flavor of the
product. The chelating source(s) contribute an undesirable flavor
to the yogurt at the high levels necessary to fortify to 1000 mg
calcium. More importantly, however, the cost of the calcium source
is prohibitive for a commercially practical product.
[0009] Similarly, the art includes numerous teachings directed
towards forming a highly soluble complex of citric acid, malic acid
and calcium. (See, for example, U.S. Pat. No. 5,186,965 entitled
"Calcium Citrate Malate Composition"). While useful, such
formulations require addition of expensive special ingredients or
extensive processing to form the materials in situ.
[0010] Still another approach is to try to employ inexpensive
insoluble calcium materials (see particularly, U.S. Pat. No.
4,784,871 entitled "Method For Producing Calcium Fortified Yogurt,"
issued Nov. 15, 1988 to Peter H. Park). The '871 patent teaches
admixing an acid soluble salt optionally with sugar with an
essential acidic fruit blend. The acidic fruit blend is allowed to
dissolve a portion of the calcium salt. About 5 to 45% of the
product of the fortified fruit blend with the partially dissolved
calcium is then admixed with a fermented yogurt base to prepare a
calcium fortified fruit containing yogurt product. Sugar is added
to the fruit to assist in the avoidance of lumping of the calcium
phosphate salt. Thus, the invention relies upon the fruit to
solvate a portion and to suspend the balance of the insoluble
calcium within the yogurt product.
[0011] While useful, not all yogurt flavors popular today contain
fruit. Thus, it would be desirable to be able to provide a
calcium-fortified yogurt that did not require the presence of a
fruit ingredient. Moreover, it would be desirable to provide a
reduced calorie yogurt fortified with calcium that did not require
sucrose. Thus, the present invention can be viewed as an
improvement upon the product and methods of the '871 patent.
[0012] Also, it is desirable to have methods of calcium
fortification that can be practiced by yogurt producers that can be
used to provide both stirred style as well as cup set style yogurts
using, to the extent possible, common techniques and equipment.
[0013] In view of the state of the art, there is a continuing need
for new and improved yogurt products, particularly those providing
enhanced nutritional benefits.
[0014] Accordingly, it is an objective of the present invention to
provide new nutritionally improved yogurt products and their
methods of preparation. A further objective is to provide new and
effective methods for calcium fortification of fermented dairy
products such as yogurt.
[0015] Another objective is to provide methods for preparing
calcium fortified yogurts that minimize milk protein
precipitation.
[0016] Still another objective is to provide methods for calcium
fortification that do not require usage of expensive calcium
materials.
[0017] Another objective of the present invention is to provide new
methods for preparing calcium supplemented yogurts fortified with
inexpensive calcium materials.
[0018] Another objective is to provide improved calcium fortified
yogurt products that exhibit both good taste and good texture.
[0019] Still another objective is to provide calcium fortified
beverages, especially milk based beverages.
[0020] Still another objective is to provide calcium fortified milk
whether refrigerated or ultra high treated milk.
[0021] Still another objective is to provide calcium fortified food
products such as milk based beverages and milk based wet foods such
as yogurt that are fortified with calcium from their native levels
by addition of insoluble calcium.
[0022] Surprisingly, the above objectives can be obtained and
improved calcium fortified yogurt products can be provided. The
present invention resides, in part, in the discovery that by
providing insoluble calcium salts, of a particular particle size,
that improved organoleptically acceptable calcium fortified
products can be obtained that do not require a fruit
ingredient.
SUMMARY OF THE INVENTION
[0023] In its preferred process aspect, the present invention
resides in methods of preparing a fermented dairy product fortified
with calcium that is visually undetectable in the final product and
of acceptable organoleptic attributes in terms of grittiness and
chalkiness. The process involves the pre fermentation addition of
calcium phosphate in the form of a fine powder essentially
characterized by a mean diameter of .ltoreq.6.mu.. The methods
comprise the steps of A) providing a warm pasteurized milk base
having a native calcium content fortified with sufficient amounts
of calcium phosphate of the requisite particle size to provide a
total calcium content ranging from 110% to 500% of the native level
and, B) inoculating the warm pasteurized calcium phosphate
fortified heat treated milk base with a starter culture; and C)
fermenting the inoculated milk base to provide a yogurt; and D)
cooling the yogurt to arrest the fermentation to provide a chilled
yogurt having a viscosity of at least 1500 centipoise (at 5.degree.
C.). The fermentation step is preferably practiced in bulk
fermentation tanks to provide stirred style yogurt products
although in-cup fermentation can be just as easily practiced to
provide set style yogurt products.
[0024] In one product aspect, the present invention resides in
products prepared by practicing the present methods.
[0025] In another product aspect of one and the same invention, the
present invention is directed towards high moisture food products
fortified with fine calcium phosphate powder such as milk based
foods or dairy products and especially fermented dairy products
such as yogurt comprising a fermented dairy product base having a
viscosity of at least 1500 cps (at 5.degree. C.) and a calcium
phosphate salt in a quantity sufficient to bring increase the
calcium content of the composition from about 250 to 1300 mg per
170 g serving (0.15% to 0.75% by weight, wet basis).
[0026] The calcium amounts include both the native level supplied
by the milk source as well as the supplemental added calcium.
[0027] The calcium salt is selected from the group consisting of
tricalcium phosphate, dicalcium phosphate, and their hydrates, and
mixtures thereof.
[0028] The fine calcium phosphate powder comprises particles having
a mean diameter 6 microns or less. ("Mean Diameter
.ltoreq.6.mu.").
DESCRIPTION OF THE DRAWING
[0029] FIG. 1 is a highly schematic process flow diagram
illustrating one embodiment of the present methods of preparation
involving the vat bulk preparation of a fermented dairy
product.
[0030] FIG. 2 is a highly schematic process flow diagram
illustrating another embodiment of the present methods of
preparation involving the cup set preparation of a fermented dairy
product.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The present invention relates to improved calcium fortified
dairy products especially fermented dairy products such as yogurt
containing pulverant or finely powdered insoluble calcium phosphate
and to their methods of preparation. Each of these product
components as well as product use and attributes and preparation
steps are described in detail below.
[0032] Throughout the specification and claims, percentages are by
weight and temperatures in degrees Centigrade unless otherwise
indicated.
[0033] Providing a Pasteurized Calcium Fortified Milk Blend
[0034] Referring now to FIG. 1, it can be seen that in preferred
form, the present methods generally designated by reference numeral
10, the first essential step is to provide a pasteurized calcium
fortified milk blend 13.
[0035] Conveniently, this first step can include the substeps of
(1) providing a calcium fortified milk base 11, (2) homogenizing
the milk base 12, (3) pasteurizing the homogenized milk base 14,
and (4) bringing the pasteurized calcium fortified milk base to
fermenting temperatures 16 such as by cooling.
[0036] Briefly, the process typically begins with milk blend
ingredients 17 such as raw milk, that can contain a combination of
whole milk, skim milk, condensed milk, dry milk (dry milk solids
non-fat or, equivalently, "MSNF"), grade A whey, cream and/or such
other milk fraction ingredients as buttermilk, whey, lactose,
lactalbumins, lactoglobulins, or whey modified by partial or
complete removal of lactose and/or minerals, other dairy
ingredients to increase the nonfat solids content, which are
blended to provide the desired fat and solids content. While not
preferred, the milk base can include a filled milk component, i.e.,
a milk ingredient having a portion supplied by a non-milk
ingredient, e.g., oil or soybean milk.
[0037] While in the present invention, particular emphasis is
directed towards fermented bovine milk products such as yogurt, the
skilled artisan will appreciate that the present invention is also
suitable for use in a wide variety of thickened dairy products,
particularly fermented dairy products such as kefir, sour cream and
the like.
[0038] Also, while bovine milk is preferred, other milks can be
used in substitution for bovine milk whether in whole or in part,
e.g., goat, sheep or even equine milk. Also, the present calcium
fortification techniques can be used to provide calcium fortified
soybean milk products. However, since the native level of calcium
in soy milk products is less than mammalian milks, e.g., about 50
mg per 100 g fluid soybean milk, greater amounts a calcium
phosphate can be added to provide equivalent calcium nutrition
levels. Conversely, if a soy milk providing only low levels of
calcium, e.g., only 100 mg calcium per 100 g serving, then about
0.5% calcium can be added to the soybean milk based milk blend 11
to supplement the native calcium of soybean milk. Also, while
cultured dairy products prepared from bovine milk are preferred,
cultured products can also be made from soybean milk based
products. If desired, the milk blend can comprise chocolate for
chocolate based milk products such as chocolate fluid milk or
chocolate soybean milk.
[0039] Conveniently, the raw milk and sweeteners (such as fructose,
corn syrup, sucrose) can be blended in a first mix tank 21 and
stored in a milk silo not shown. Stabilizers and thickeners such as
starch, gelatin, pectin, agar and carrageenan can also be added if
desired. The minor dry ingredients are combined with the sweetened
milk to form the milk base 11 can conveniently in a separate mixing
vessel (not shown).
[0040] The milk blend 21 additionally essentially comprises an
added finely powdered calcium phosphate to fortify the milk blend
with calcium. The particular degree of calcium content and
fortification can be expressed in several different ways. Most
broadly, sufficient amounts of calcium salt is added to provide a
total (native plus supplemental) calcium content of mammalian milks
of about 0.25 to 0.75% by weight. Such a level provides about 425
to 1300 mg of total calcium per 170 g (6 oz) serving and about 565
to 1725 mg of total calcium in a 227 g (8 oz) serving. Preferred
for use herein are yogurts fortified with calcium providing about
500 to 1300 mg per serving whether from the six or eight ounce
serving. Most preferred are yogurts providing about 500 to 800 mg
calcium per serving (6 oz), that is, a yogurt providing 50% to 100%
of the current recommended daily allowance for calcium.
[0041] Useful herein as the source of supplemental calcium is
calcium phosphate. Calcium phosphate is generally available as a
mono basic (CaH.sub.4(PO.sub.4).sub.2.H.sub.2O), di-basic
(CaHPO.sub.4.2H.sub.2O) or tribasic (Ca.sub.3(PO.sub.4).sub.2)
salts. Preferred for use herein is tricalcium phosphate,
Ca.sub.3(PO.sub.4).sub.2, ("TCP") because of its high weight
percentage of calcium (about 38%). Moreover, TCP is slightly more
soluble than other calcium phosphate salts.
[0042] A useful tricalcium phosphate starting material is also
known as tribasic calcium phosphate or tricalcium orthophosphate
and is available in food chemicals codex grade from Gadot
Biochemical Industries Ltd., P.O.B. 10636 Haifa Bay 26118 Israel
under the trade name "TCP-LD or Tricalcium Phosphate LD" having the
general formula 3Ca.sub.3(PO.sub.4).sub.2.Ca(OH).sub.2. This
product provides an assayed calcium content of from 34 to 40% by
weight. Less preferred but nonetheless useful herein is anhydrous
dicalcium phosphate, also known as anhydrous dibasic calcium
phosphate, having a formula of CaHPO.sub.4. An anhydrous dicalcium
phosphate material is also available from Stauffer in food chemical
codex grade, providing an assay calcium content from about 30 to
about 31.7% calcium by weight. Other calcium phosphate hydrates
also can be useful, including, but not limited to, calcium
pyrophosphate, calcium hexametaphosphate and monobasic calcium
phosphate.
[0043] Phosphate salts are a preferred source of calcium, not only
because of their acid solubility and weight ratios, but also
because they are available commercially as a pure precipitate from
reacting Ca(OH).sub.2 with phosphoric acid. By appropriate size
classification, a calcium phosphate of requisite size can be
obtained in commercial quantities.
[0044] The skilled artisan will appreciate that while the present
calcium phosphate salts are characterized herein as insoluble, of
course, some small percentage will dissolve in water depending in
part upon the temperature and pH. However, at the concentrations of
calcium salt used both in the slurry and the yogurt products
herein, the great percentage is in a solid state.
[0045] Unfortunately, other calcium salts that might otherwise be
thought as useful but cannot be employed for one reason or another
include, calcium ascorbate (too expensive), calcium citrate
(creates a chalky product and imparts a bad after taste), calcium
carbonate (too effervescent especially in an acidic food product
such as cultured dairy products and imparts a bad off-flavor),
calcium gluconate (too expensive), calcium lactate (too expensive
and bad flavor), and calcium sulfate (too strongly flavored).
Furthermore, these soluble calcium salts may cause premature
protein precipitation during pasteurization of the yogurt base,
resulting in unacceptable yogurt quality.
[0046] Most importantly, the calcium phosphate flour has a particle
size having a mean diameter of less than or equal to six microns
(".ltoreq.6 .mu.m"). Having a calcium phosphate being of
sufficiently reduced particle size is important to maintaining the
calcium in suspension in the milk blend for extended times and to
avoiding a "grittiness" organoleptic attribute in the finished
yogurt. Preferably, the calcium phosphate has a particle size of
less than or equal to 5 microns (".ltoreq.5 .mu.m") and for best
results less than 11 .mu.m.
[0047] Of course, the calcium phosphate material will have a
particle size distribution curve. Surprisingly, if a significant
amount of the calcium phosphate (i.e., >10%) is larger than
about 150 microns, then the calcium phosphate begins to become
perceptible as imparting an undesirably "chalky" mouth feel. For
the very best product, preferred herein are yogurt finished
products wherein the calcium phosphate particle size is such that
the mean particle size is less than four microns and at least 90%
of the calcium phosphate has a particle size of less than about
seven microns.
[0048] A useful technique for ensuring that the calcium phosphate
is of the requisite particle size in small scale production is to
screen a calcium phosphate starting material. For example, a
maximum of 0.5% on a #140 U.S. standard sieve and a minimum of 95%
through a #325 U.S. standard sieve is preferred (wet sieve
method).
[0049] Optionally, all or a portion of the calcium phosphate can be
added blended with the various stabilizers, e.g., gums, starches
after the bulk ingredients are mixed as indicated by dotted line
having reference numeral 19.
[0050] Next, the milk base 11 is homogenized 12 in a conventional
homogenizer to disperse evenly the added materials and the fat
component supplied by various ingredients thereby forming an
homogenized milk base 15. If desired, the milk base 11 can be
warmed 14 prior to homogenization from typical milk storage
temperatures of about 5.degree. C. to temperatures of about 65 to
75.degree. C. with steam.
[0051] This homogenized milk base 15 is then pasteurized 16,
typically by heating for times and temperatures effective to
accomplish pasteurization to form a calcium fortified pasteurized
milk base. As is well known, the milk base 11 can be heated to
lower temperatures for extended times, e.g., 88.degree. C. for 30
minutes, or alternately to higher temperatures, e.g., 95.degree.
C., for shorter times, e.g., for about 38 seconds. Of course,
intermediate temperatures for intermediate times can also be
employed. Other pasteurization techniques can be practiced (e.g.,
light pulse, ultra high pressure, etc.) if effective and
economical. In certain commercial practices, the sequence of the
homogenization and pasteurization steps can be reversed.
[0052] In still other embodiments of the present invention, such as
for the preparation of shelf stable fluid milk products, the
heating step 16 can be extended to provide an ultra heat treatment
or "UHT" fluid milk product that is calcium fortified.
[0053] The homogenized and pasteurized base is then brought to
incubation temperature, usually about 40.degree. C. to 60.degree.
C., preferably about 40 to 46.degree. C. When heat pasteurization
is employed, this step typically is a cooling step 16.
[0054] Thereafter, the homogenized and pasteurized milk blend is
inoculated with a desired culture 20. Usually, a combination of
Lactobacillus bulgaricus and Streptococcus thermophilus bacteria is
added to begin the fermentation process. In other variations,
Lactobacillus acidophilus or L. bifidus can also be added. The
present methods further essentially comprise fermenting 22 or
culturing the inoculated milk blend to desired endpoints of pH,
titratable acidity, time, etc. to provide a warm cultured dairy
product such as a yogurt 23. The fermentation step 22, is continued
an in highly preferred embodiments, quiescently continued (i.e.,
without agitation), until the pH of the milk blend reaches
approximately 4.4 to 4.6 to form the yogurt base. Depending upon
temperature and amount of culture added, this can take from about
three to about 14 hours. It is important that the mixture not be
agitated during the fermentation process to allow proper curd
formation. It is an advantage of the present invention that by
selection of such a finely powdered calcium phosphate that
surprisingly, the added calcium material does not settle out during
fermentation even when quiescently practiced.
[0055] The particular fermentation endpoint pH can vary modestly.
Typically, the endpoint pH can range from about 4.2 to 4.6,
preferably about 4.45 to 4.55.
[0056] When the proper pH has been reached, the present methods
further essentially comprise cooling 24 the warm yogurt (e.g., to
about 2 to 21.degree. C., preferably about 5.degree. C.) to arrest
further growth and any further drop in the pH to form a cooled
yogurt 28 or calcium fortified yogurt base.
[0057] The yogurt base 28 thus prepared importantly is
characterized by a viscosity of at least 1500, preferably at least
2300 cps (at 5.degree. C.). Such a viscosity is helpful to
suspending the insoluble calcium salt. At a viscosity of 1500 cps,
the yogurt is a thinner substance useful for a yogurt beverage-type
product. Yogurt viscosities can range up to 25000 cps.
[0058] While the above described particular process can be used,
any vat set fermented yogurt can be used.
[0059] Moreover, although a live yogurt product is preferred, the
present invention can also be used in yogurt-based foods as
distinguished from a yogurt product. For example, a shelf stable
yogurt-based product is prepared by heat treating a yogurt to
inactivate the culture and packaging aseptically (not shown). In
this variation, the pH of the yogurt based product can be adjusted
for taste or for compatibility with other ingredients. For example,
the pH can be adjusted upwards substantially for a chocolate
flavored yogurt based product.
[0060] In a less preferred embodiment, the pre-fermentation
addition of calcium phosphate of the present invention can
optionally be combined with the post fermentation addition 30 of a
calcium slurry 31 as described in U.S. Pat. No. 5,820,903 as
indicated by the dotted line. While useful as described in the '903
patent, such post addition requires separate make up tanks, adds
extra moisture to the yogurt and can require pasteurization of the
calcium slurry prior to addition to the yogurt base 28. Such post
fermentation addition thus adds extra equipment, steps and thus
extra cost to yogurt production.
[0061] If practiced, step 30 involves mixing the calcium phosphate
with water to form a slurry 31. Generally, the slurry 31 can
comprise about 20 to 50% calcium phosphate, preferably 25 to 40%
and about 50 to 75% water, preferably about 60 to 70%.
[0062] The present calcium phosphate materials are highly alkaline,
especially when dispersed in water. In order to avoid raising the
pH of the yogurt when the calcium phosphate is admixed, it is
desirable to "acidify" the calcium phosphate slurry 31. That is,
the pH is brought to the approximate acidity of the yogurt being
fortified by addition of an acid. It is also important to avoid
over acidifying the calcium phosphate. Thus, the pH should be
within a few tenths of a pH of the yogurt.
[0063] Since the pH of the yogurt generally will range from about
4.4 to 4.6, good results are generally obtained when the aqueous
slurry pH ranges from about 4.0 to 4.6, preferably about 4.4 to
4.6. The preferred pH of the calcium aqueous slurry is at the pH of
the yogurt or below.
[0064] The slurry pH is adjusted to particular values within the
above range by addition of an acid or acidulant. Useful herein as
the acidulant is adipic, citric acid, fumaric, malic acid, and
mixtures thereof. Preferred for use herein as an acidulant is
citric acid.
[0065] The slurry makeup can include a supplemental heating step
with vigorous agitation (not shown) to pasteurize and insure
hydration and suspension of the insoluble calcium salt. Thereafter,
the slurry can be heated to about 73.9 to 87.8.degree. C. (165 to
190.degree. F.). The preferred temperature of the calcium slurry is
the same as or below the yogurt upon admixture. Thus, if a heating
step is employed, thereafter, the slurry can be cooled to or below
the temperature of the yogurt base (2 to 21.degree. C. depending
upon whether added to the yogurt base before or after the yogurt
base has been cooled) prior to admixture therewith to reduce
thermal shock to the yogurt. The heating substep not only aids in
dispersion of the calcium but also insures that the slurry is
pasteurized prior to admixture with the yogurt base. For example,
if the yogurt base is at 5.degree. C., the slurry should be about 2
to 5.degree. C.
[0066] The slurry 31 and yogurt 28 are admixed 40 using minimum
shear so as to avoid degrading the yogurt base's viscosity. As
illustrated in FIG. 1, an in-line static mixer 41 can be used to
blend the slurry into the yogurt base by static mixing to minimize
shear.
[0067] If desired, the yogurt base cooling and calcium admixing
steps can be reversed. In this variation, a warm slurry is added to
the still warm yogurt base. The blend is then cooled thereafter to
about 5.degree. C.
[0068] In certain embodiments, particularly low fat and/or low
calorie variations, the yogurt product herein comprises a high
potency non-nutritive carbohydrate sweetening agent. For example,
high potency sweeteners include aspartame, sucrose, potassium
acelsufame, saccharin, cyclamates, thaumatin and mixtures thereof.
Especially preferred for use herein is aspartame.
[0069] If aspartame is employed, an aqueous dispersion 38 thereof
can be prepared and added to the yogurt base. The aspartame is
preferably added separately from the calcium slurry since aspartame
tends to degrade under the processing conditions of the slurry
preparation.
[0070] The calcium slurry 31 can also contain vitamin D. Vitamin D
enhances calcium absorption. Vitamin D can be added up to 400 I.U.
per quart of food "yogurt" per the yogurt standards of identity by
this technique or otherwise.
[0071] If desired, various flavors can be added with or in a manner
similar to the aspartame dispersion 38. Illustrative flavors
include vanilla, chocolate, amaretto cheesecake, white chocolate,
Boston cream pie, Caf Au Lait, caramel apple, banana cream pie and
mixtures thereof.
[0072] If desired, the calcium fortified yogurt 28 can additionally
include a conventional fruit sauce or puree 51. If present, the
fruit constituent can comprise about 5 to about 15% of the yogurt
product. The present method thus can comprise the optional
additional step of adding a fruit sauce or puree 50.
[0073] In the manufacture of Swiss-style yogurt, a fruit flavoring
is blended substantially uniformly throughout the yogurt after
fermentation is complete but prior to packaging 50. A second static
mixer 54 can be used to blend the fruit sauce into the yogurt with
minimal shear.
[0074] In the manufacture of "sundae" style yogurt, fruit sauce or
puree is deposited at the bottom of the consumer container, and the
container is then filled with the yogurt mixture. To prepare a
sundae style yogurt product employing a stirred style yogurt, the
milk base is prepared with added thickeners and/or stabilizers to
provide upon resting a yogurt texture that mimics a "sets style
yogurt. In this variation, the fruit is added directly to the
container, typically to the bottom, prior to filling with the
yogurt.
[0075] The fruit flavoring sauce or puree used in the invention can
be any of a variety of conventional fruit flavorings commonly used
in yogurt products. Typical flavorings include strawberry,
raspberry, blueberry, strawberry-banana, boysenberry,
cherry-vanilla, peach, pineapple, lemon, orange and apple.
Generally, fruit flavorings include fruit preserves and fruit or
fruit puree, with any of a combination of sweeteners, starch,
stabilizer, natural and/or artificial flavors, colorings,
preservatives, water and citric acid or other suitable acid to
control the pH. Minor amounts (e.g., providing less than 50 mg of
calcium-per 226 g serving) of calcium can be added to the fruit to
control the desired texture of the fruit preparation typically
provided by a soluble calcium material such as calcium
chloride.
[0076] If aspartame is added to the yogurt base, all or a portion
of the aspartame can be pre-blended with the fruit flavoring.
[0077] If desired, the milk base can be formulated with thickeners
and setting agents that will set up after cup filling that will
impart a texture to the yogurt that mimics a set-style type yogurt
product.
[0078] The products can additionally include a variety of other
ingredients to increase their nutritional, organoleptic or other
consumer appeal, e.g., fruit pieces, nuts, partially puffed
cereals, etc.
[0079] The yogurt base can optionally further comprise a nutritive
carbohydrate sweetening agent(s). Exemplary useful nutritive
carbohydrate sweetening agents include, but are not limited to,
sucrose, high fructose corn syrup, dextrose, various DE corn
syrups, beet or cane sugar, invert sugar (in paste or syrup form),
brown sugar, refiner's syrup, molasses (other than blackstrap),
fructose, fructose syrup, maltose, maltose syrup, dried maltose
syrup, malt extract, dried malt extract, malt syrup, dried malt
syrup, honey, maple sugar, except table syrup and mixtures
thereof.
[0080] Preferably, the yogurt is unaerated. That is, the yogurt
phase(s) can have a density of from about 0.9 to 1.2 g/cc. However,
in other variations the yogurt can be aerated to about 0.5 to 0.8
g/cc, especially for soft serve frozen yogurt products. The yogurt
product, whether or not aerated, can be frozen, e.g. to -2.degree.
C. to -5.degree. C., to provide soft-serve frozen yogurt products,
or frozen to colder temperatures, e.g., -8.degree. C. to
-15.degree. C. to provide harder, more ice cream type properties.
Such freezing can after packing or otherwise in accordance with
common practice.
[0081] The calcium fortified yogurt is then charged to a
conventional container.
[0082] The present methods can further comprise charging or filling
60 the calcium fortified yogurt 28 or inoculated milk blend with or
without fruit (whether blended with the yogurt base or as a
separate phase) to containers such as 6 oz. or 8 oz. cups such as a
coated paper or plastic cup (polypropylene or polystyrene) or other
suitable containers or packages of desired shape. For example,
recent new commercial yogurt products have included being filled
into tubes fabricated from flexible film. After filling, the filled
containers are applied with a lid or other closure, assembled into
cases and entered into refrigerated storage for distribution and
sale size, etc. to provide finished refrigerated products 61 that
are stored and/or and the present methods can further comprise
distributing 62 through refrigerated storage conditions.
[0083] The methods depicted in FIG. 1 are especially suitable for
use in connection with the commercial production of stirred style
yogurt products. Of course, the skilled artisan will appreciate
that other calcium fortified cultured dairy products such as kefir,
sour cream, cottage cheese, and cheeses can be prepared from the
described calcium fortified pasteurized milk blends described. The
calcium fortified dairy products can be used or consumed in
conventional or further processed and combined with other food
ingredients to provide calcium fortification.
[0084] Reference is now made briefly to FIG. 2 which illustrates
embodiments of the present methods that are particularly suitable
for use in providing set style yogurt products by in cup
fermentation. For convenience, FIG. 2 bears similar reference
numerals to FIG. 1 for like steps and intermediate products. The
sequence and practice of steps in this variation is similar to
those described above and depicted in FIG. 1 through the step of
inoculating 20 the calcium fortified milk base 19 to provide an
calcium fortified inoculated warm milk 23. However, FIG. 2, depicts
that the present methods can comprise reversing the order of the
cup filling and fermentation steps such as to include filling 42
the cups or containers with inoculated warm milk 23 prior to
fermentation to provide cups 43 filled with inoculated warm milk.
Thereafter, the methods can involve fermenting 44 in the cup or in
situ fermentation such as by holding the filled cups in
fermentation rooms maintained at suitable temperatures (e.g.,
40.degree. C.-60.degree. C.). In highly preferred variations such
fermentation is practiced quiescently for times sufficient to
provide endpoint pH values, titratable acidity, viscosity, etc. It
is a surprising advantage of the present invention that by
selecting and employing a finely powdered calcium phosphate that
settling of the calcium mineral fortifying ingredient is minimized
during the quiescent fermentation step.
[0085] FIG. 2 further depicts that the methods can involve adding
50 a fruit sauce or puree 51 to either the inoculated warm milk or,
less preferably (as indicated by dotted lines), the cups or
containers. Thereafter, the methods can involve cooling 24 the warm
fermented yogurt 23 to arrest the fermentation step such as by
holding the cups in a cooler or cooling room maintained at
refrigerated temperatures of 5.degree. C.-10.degree. C. As the
yogurt cools, the texture sets to form a calcium fortified cup set
style yogurt products of the present invention.
[0086] Description of Finished Product Attributes
[0087] The present invention provides both fermented dairy products
and methods for addition of a high level of calcium to yogurt
products. The resulting yogurt has an acceptable texture and
flavor. The present invention provides calcium fortification of
yogurts that do not contain a fruit preparation.
[0088] While the invention finds particular suitability for a
connection with yogurt, the skilled artisan can appreciate that the
invention can also be used in connection with other fermented dairy
products such as sour cream and kefir. Also, non-fermented dairy
products having the requisite viscosity can be prepared, e.g.,
starch gels (puddings), frozen desserts, cheeses (e.g., processed
cheese). In such products, the particular pH of the slurry can be
adjusted to the pH typical of the product to be fortified.
EXAMPLE 1
[0089] A calcium fortified stirred style yogurt of the present
invention was prepared as follows:
[0090] 150 kilograms of low fat yogurt base mix was produced using
whole milk, skim milk, and nonfat dry milk to make a blend with
2.8% butterfat and 13.2% milk solids non fat. To this blend was
added 19.5% liquid sugar, 1.5% modified food starch, 0.5% gelatin,
and 0.18% of the fine tricalcium phosphate from Godat Biochemical.
Dry ingredients were incorporated with a powder funnel into a
centrifugal pump to disperse the dry particulates.
[0091] A starter culture was prepared by heat treating skim milk
fortified with nonfat dry milk to 12% milk solids. This mixture was
held at 74.degree. C. for 45 minutes and then cooled while
agitating the mixture. When the mix was cooled to 46.degree. C., a
commercial freeze dried or frozen yogurt starter culture was added.
This was allowed to mix for sufficient time to disperse the starter
culture innoculum. The agitation was then turned off and the
culture was allowed to ferment until the pH of the mixture was
reduced to 4.6 by the lactic acid production of the bacteria. The
culture was to cooled to 4.degree. C.
[0092] This mix was then heated through a plate heat exchanger to
74.degree. C. and homogenized through a two stage homogenizer at
1000 psi first stage and 500 psi second stage for a total of 1500
psi. The homogenized mix was then further heated in a plate heat
exchanger to 90.degree. C. and was passed through a holding tube
that maintains the temperature for 8 minutes to form a pasteurized
calcium fortified milk blend or base. The heat treated base was
then cooled to fermentation temperatures in a plate heat exchanger
to 43.degree. C. to form a yogurt base.
[0093] The yogurt base was then blended with 5% starter culture by
weight to form an inoculated calcium fortified yogurt base. The
inoculated base was fermented at 43.degree. C. to a pH of 4.5. The
fermented base was then cooled in a plate heat exchanger to
5.degree. C. At this point a strawberry fruit preparation from was
added at 5% by weight along with at 0.002% color, and 0.2% Natural
Strawberry flavor.
[0094] This mixture was well blended and filled into cups The final
product was then moved to a refrigerated cooler at 4.degree. C. and
stored.
[0095] The finished product had a pleasant acceptable flavor and
texture and did not have precipitated proteins.
[0096] Products of substantially equivalent organoleptic attributes
are obtained when the liquid sugar is replaced by aspartame to
equivalent sweetness levels and when the yogurt products
additionally comprises supplemental vitamin D.
EXAMPLE 2
[0097] A calcium fortified cup set style yogurt product of the
present invention was prepared as follows:
[0098] The inoculated yogurt base prepared as described above in
Example was filled into cups and sealed prior to moving to a
temperature controlled room for fermentation at 46.degree. C.
Fermentation was checked by sampling cups until a pH of 4.5 was
measured which was achieved in 3.5 hours. After fermentation to
desired pH, the cups were then moved to a refrigerated cooler at
4.degree. C. and cooled rapidly to arrest fermentation to provide
finished calcium fortified yogurt products.
* * * * *