U.S. patent application number 10/315780 was filed with the patent office on 2003-05-08 for bleached grain and grain products.
Invention is credited to Metzger, Lloyd E..
Application Number | 20030087012 10/315780 |
Document ID | / |
Family ID | 23551660 |
Filed Date | 2003-05-08 |
United States Patent
Application |
20030087012 |
Kind Code |
A1 |
Metzger, Lloyd E. |
May 8, 2003 |
Bleached grain and grain products
Abstract
The present invention describes bleached grain products such as
bleached whole wheat flour that are obtained having the color and
taste of white flour by bleaching whole wheat kernels prior to
conventional flour milling. The wheat kernels are treated with a
peroxide solution to lighten the color of the bran layers. The
bleached grain kernels can be tempered and milled into whole grain
flours having 10% to 12% dietary fiber from the bran but which are
white in color and bland in flavor. The whitened, high fiber whole
wheat flours can be used to prepare good tasting, and nutritious
products such as baked goods such as breads and pastries as well as
pasta product, and ready-to-eat cereals or grain based snacks.
Inventors: |
Metzger, Lloyd E.;
(Champlin, MN) |
Correspondence
Address: |
General Mills, Inc.
Number One General Mills Blvd.
Minneapolis
MN
55426
US
|
Family ID: |
23551660 |
Appl. No.: |
10/315780 |
Filed: |
December 10, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10315780 |
Dec 10, 2002 |
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09392699 |
Sep 9, 1999 |
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6497909 |
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Current U.S.
Class: |
426/254 |
Current CPC
Class: |
A23B 9/30 20130101; A23L
5/49 20160801; A21D 2/04 20130101 |
Class at
Publication: |
426/254 |
International
Class: |
A23L 001/22 |
Claims
What is claimed is:
1. A method of bleaching cereal grains, comprising the steps of: A.
treating whole grain kernels having an exterior bran layer with
peroxide to decrease the color of the bran layer to provide a
lightened grain kernel.
2. The method of claim 1 wherein the cereal grain is cleaned to
provide milling quality grain prior to treatment with peroxide.
3. The method of claim 1 wherein the cereal grain is selected from
the group consisting of wheat, rice, barley, corn (maize), oats,
triticale, amaranth, and soybeans.
4. The method of claim 3 wherein the cereal grain is selected form
the group consisting of wheat, rice, barley and soybeans.
5. The method of claim 4 wherein the cereal grain is selected from
the group consisting of wheat and rice.
6. The method of claim 1 wherein the cereal grain is wheat.
7. The method of claim 6 wherein the cereal grain is a red
wheat.
8. The method of claim 6 wherein the cereal grain is a white
wheat.
9. The method of claim 8 wherein the white wheat is a hard
wheat.
10. The method of claim 1 wherein the treatment with peroxide step
A comprises applying a peroxide solution to the cereal grain.
11. The method of claim 10 comprising applying sufficient amounts
of the peroxide solution to wet substantially the entire surfaces
of the grain kernels.
12. The method of claim 11 wherein the treatment with peroxide step
A comprises spraying the peroxide solution on to the grain
kernels.
13. The method of claim 11 wherein step A includes applying an
aqueous solution of about 6% to 40% H.sub.2O.sub.2at a temperature
of about 50.degree. to 165.degree. for about 20 seconds to five
minutes.
14. The method of claim 14 applying about 1 to 5 parts
H.sub.2O.sub.2 per 100 parts of grain.
15. The method of claim 1 additionally comprising the step of B
treating whole grain kernels with an alkaline solution.
16. The method of claim 13 wherein step B applying an alkaline
solution comprising about 1% to saturation in amounts of about 10
parts to 15 parts (dry weight) of alkaline material per 100 parts
grain.
17. The method of claim 16 wherein step B is practiced at a
temperature of about 130.degree. to 165.degree. F.
18. The method of claim 15 wherein step B is practiced as a
separate prior step.
19. The method of claim 18 additionally comprising a washing step
intermediate step B and step A.
20. The method of claim 18 additionally comprising a drying step
intermediate step B and step A.
21. The method of claim 15 wherein step B is practiced simultaneous
with step A.
22. The method of claim 21 wherein the alkaline solution and
peroxide solution are combined immediately prior to application
onto the grain.
23. The method of claim 22 wherein the treatment is practiced at
temperature of 100.degree. to 165.degree. F.
24. The method of claim 23 wherein the treatment step is practiced
with supplemental heating during the step.
25. The method of claim 24 wherein at least a portion of the
supplemental heating is supplied by microwave heating.
26. The method of claim 1 additionally comprising the step of
tempering the treated grain to provide a tempered grain.
27. The method of claim 15 additionally comprising the step of
tempering the treated grain to provide a tempered grain.
28. The method of claim 26 additionally comprising the step of
milling the tempered grain to provide a whole grain flour.
29. The method of claim 28 wherein the milling step is practiced to
provide a whole grain flour without a germ fraction.
30. The product prepared by the method of claim 1.
31. The product prepared by the method of claim 3.
32. The product prepared by the method of claim 5.
33. The product prepared by the method of claim 7.
34. The product prepared by the method of claim 10.
35. The product prepared by the method of claim 15.
36. The product prepared by the method of claim 16.
37. The product prepared by the method of claim 18.
38. The product prepared by the method of claim 22.
39. The product prepared by the method of claim 29.
40. An improved whole wheat flour prepared from peroxide bleached
whole grains of wheat having a white color and a dietary fiber
content of about 10% to 12%.
41. The improved whole wheat flour of claim 40 substantially free
of any bromate bleaching agent.
42. The improved whole wheat flour of claim 41 prepared from white
wheat.
43. The improved whole wheat flour of claim 41 having a pH of about
6.3 to 6.7.
44. The improved whole wheat flour of claim 43 prepared from hard
white wheat.
45. A finished baked good prepared from the flour of claim 40.
46. The flour of claim 40 admixed with sugar, salt, and
leavening.
47. A method of bleaching cereal grains, comprising the steps of:
applying whole cereal grains with an alkaline solution of sodium
bicarbonate or sodium hydroxide at a concentration of about 1% to
10% and a temperature of about 50.degree. to 165.degree. F. in a
weight ratio of alkaline solution to grain ranging from about
10:100 to about 15:10 for about 30 seconds to three minutes, and
then applying a peroxide solution at a concentration of about 4% to
20% H.sub.2O.sub.2 to the cereal grains for about 30 seconds to the
three minutes at a temperature of about 50.degree. to 165.degree.
F. to provide bleached cereal grains.
48. A method of reducing mycotic contamination of cereal grains,
comprising the steps of: (a) providing alkaline solution and a
peroxygen solution; (b) applying grain kernels with the alkaline
solution to provide grain kernels wetted with the alkaline
solution; (c) draining the alkaline solution from the grain
kernels; (d) drying the grain kernels wetted with the alkaline
solution to provide dried alkaline treated grain kernels; and then
(e) applying the grain kernels with the peroxygen solution whereby
to cause the alkaline solution and the peroxygen solution to
chemically react on the surface of the grain kernels.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to food products and to
methods for their preparation. More particularly, the present
invention is directed towards bleached grain products such as whole
wheat flour, to bleached grain intermediate products such as
bleached wheat kernels and to their methods of preparation.
BACKGROUND OF THE INVENTION
[0002] The present invention provides improvements in the
processing or treatment of grains such as wheat. More particularly,
the present invention is directed towards the provision of whole
grain flour such as whole wheat with the color and taste comparable
to white flour or a "white" whole wheat flour. Also, the present
invention provides methods for preparing such improved white whole
wheat flour and further to intermediate products useful in the
production of such improved finished products as white whole wheat
flour. Such intermediate products include, for example, bleached
grain kernels such as bleached wheat kernels.
[0003] Most consumers have experienced and readily recognize the
difference between whole wheat bread and ordinary white bread. Most
consumers also know that whole wheat bread is more nutritious, but
consume white bread anyway, because they like the taste better.
This is especially true of children who can be particularly
selective in food choices.
[0004] Through a particular treatment process, the present
invention is able to lighten the darker color of whole wheat flour,
and all but eliminate the bitter flavors. As a result, the present
invention provides whole wheat flours that can be used to provide
finished whole wheat products that look and taste as good as those
made with regular white flour.
[0005] The principle species of wheat are Triticum vulgare or bread
wheat; T. durum which has extra hard kernels used primarily for
macaroni and related pasta products; and T. compactum or club
wheat, which has very soft kernels. Numerous varieties and
cultivars within each species are known.
[0006] All wheat generically comprise a major starchy endosperm, a
smaller germ or sprouting section of the seed and a surrounding
bran or husk layer. The endosperm makes up about 82-83% of the
wheat kernel and is used in the production of flour. Typically, the
bran makes up 14-15%, is removed from the kernel and is used in
animal and poultry feed. However, the bran can also be milled along
with the endosperm to produce whole wheat flour. The germ is
usually separated from the rest of the kernel because its fat
content limits the shelf life of the flour. The bran with or
without the germ is sometimes referred to as "millfeed". Some
special purpose whole grain flours include not only the bran but
also the germ fraction.
[0007] In the United States, wheat is classified according to
whether it is hard or soft, white or red, and planted in winter or
spring.
[0008] Soft or spring wheat is typically planted in the spring and
harvested later in the fall. Soft wheat is normally white wheat.
White soft wheat is used for the donut and pastry industries since
a white color and bland taste are essential flour quality
attributes.
[0009] Hard or winter wheat is typically planted in the fall and
harvested the following season in mid-summer. Winter wheat is
normally red. Hard or red wheat is used for bread production. Red
wheat has a distinctive taste due to tannins in the bran. To
minimize the amount of these flavor-bearing tannins, the wheat
grain is milled so as to have as small a fraction as possible of
the bran containing these tannins. Naturally white hard wheat is
also increasingly available commercially and being used more and
more.
[0010] Even though the endosperm fraction is about 83%, in a
typical flour milling process, the extraction rate of white patent
flour generally runs about 72-75%. That is, for every hundred
pounds of wheat, about 72-75 pounds of flour is obtained. This
flour contains about 1-2% dietary fiber from small amounts of the
bran. The balance millfeed is very low value comprising bran and
germ although containing some of the desirable endosperm.
[0011] The milling process can be adjusted to obtain an increase in
the flour yield but at the cost of including some of the bran. The
presence of bran may lower the quality and thus value of the flour
more than the increase in the value of the increase in yield. That
is, the amount of flour obtained during the milling process is
limited by contamination of the flour with bran that deteriorates
flour quality. For flour made from red wheat, less bran in the
flour can be tolerated due to the presence of more color and flavor
tannins in the bran. The darker bran typically makes the flour
grayish in color, and also imparts bitter flavors.
[0012] The present invention provides a particular chemical
lightening treatment or wetting process, or wet bleaching process
that bleaches wheat kernels after cleaning but prior to milling.
Since wheat is typically wet tempered prior to milling anyway, this
process is commercially practical with existing milling
systems.
[0013] The principle advantage of the present invention is the
provision of white whole grain flour having a high fiber content
(.apprxeq.11-12%) and other nutritional advantages of a whole grain
flour that nonetheless has a white color and bland flavor
comparable to conventional white flour. Since additional endosperm
is associated with the bran is also included, the yield of the
flour milling process is surprisingly and, dramatically increased.
More surprisingly, the amount of flour obtained can be increased
without deterioration in flour quality in terms of color and
flavor.
[0014] Still another benefit is that the present invention provides
enzyme inactivation that increases the stability of the flour.
[0015] Still another benefit is that the present invention provides
substantial reductions in the viability of toxin producing molds
and reductions in levels of mycotic toxins in the flours that can
occur as a result of mold growth prior to milling.
[0016] These and further objects and advantages of the present
invention will become clearer in light of the following detailed
description of an illustrative embodiment of this invention
described in connection with the drawings.
SUMMARY OF THE INVENTION
[0017] In its method of preparation aspect, the present invention
resides in methods of treating wheat prior to milling, essentially
comprising the step of:
[0018] treating whole grain kernels having an exterior bran layer
with peroxide to decrease the color of the bran layer to provide a
lightened grain kernel.
[0019] In its principal product aspect, the present invention
resides in finished whole flour products characterized by high
levels of dietary fiber, i.e., from the bran but which nonetheless
have a white color and bland flavor of white flavors having only 1%
to 2% fiber from bran.
[0020] In still another product aspect of one and the same
invention, the present invention further provides intermediate
products such a bleached or whitened grain kernels suitable for use
in producing the present finished whole grain flours.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention is directed towards bleached grain
products such as whole wheat flour, to bleached grain products
intermediate products such as bleached wheat kernels and to their
methods of preparation. Each of the treatment method steps are
described in detail as follows.
[0022] The starting material for use herein is cleaned dry or
"milling quality" wheat kernels. Unprocessed commodity wheat is
first prepared for milling in substantially conventional manner.
The wheat preparing process typically involves several well-known
cleaning steps to produce clean dry milling quality wheat. For
example, the wheat preparing process typically involves a magnetic
separator that removes iron or steel particles that dirty the wheat
during harvest and transportation. Various screening steps such as
reciprocating screens are also used to separate stones, sticks and
other coarse and fine materials. The wheat can be fed to an air
aspirator to remove other light impurities. A disc separator can be
used to remove barley, oats, cockle and other foreign seeds. A
scourer such as beaters in a screen cylinder scour off impurities
and roughage. The various cleaning steps can be practiced in any
convenient manner to provide the dry cleaned or milling quality
wheat starting material for use herein.
[0023] The preferred starting material preferably consists of whole
intact kernels to minimize exposure of the endosperm to the
bleaching treatment steps herein.
[0024] The present invention finds particular suitability for use
in connection with the provision of whole flours of wheat. While
the present invention is thus described with particular reference
to wheat, the present invention also finds usefulness in the
provision of whole flours of other common major cereal grains
including those of corn (maize), soybeans, oats, rice, barley and
mixtures thereof. While these major grains are most popular, minor
useful grains include amaranth, millet, sorghum, triticale, flax
and mixtures thereof. The present invention also finds particular
suitability for use for rice products.
[0025] While red wheat can be beneficially treated using the
present methods, the preferred starting material is white wheat
whether of a soft variety or the less common hard variety. White
wheat is preferred due to brightness or whiteness of the whole
wheat flour prepared from bleached wheat from white wheat as a
starting material.
[0026] The present methods essentially comprise the step of
treating the grain with a peroxygen compound especially hydrogen
peroxide H.sub.2O.sub.2. The peroxide treatment results in bleached
or whitened whole grain kernels.
[0027] In the preferred embodiment, the present methods involve a
combination treatment comprising a treatment of the wheat kernels
with an alkaline solution and a peroxide solution. In a less
preferred embodiment, the present methods comprise treatment of the
grain with only a peroxide solution. In the most preferred
embodiment, the grain is treated with the alkaline solution and the
peroxide solution simultaneously. In another embodiment, the
alkaline treatment and peroxide treatment are practiced as separate
sequential steps.
[0028] A peroxide bleaching or whitening treated is desirable
herein since the residual peroxide degrades into harmless oxygen
and water. In contrast, other types of bleaching techniques can
result in either undesirable modification of the function
properties of the finished flour or undesirably high or even
illegal concentrations of residual bleaching agents or both.
[0029] Useful herein are peroxygen concentrations of about 5% to
40% , preferably about 6% to 40% and most preferably about 10% to
40% .
[0030] The temperature of the peroxide treatment step can range
from ambient temperature (about 50.degree. F.) to about 165.degree.
F. (73.9.degree. C.). Preferably, both the peroxide solution and
the grain are each warm. Better results are obtained when the
treatment step is practiced with both grain and peroxide solution
heated to about 130.degree. to 165.degree. F. (54.4.degree. to
73.9.degree. C.), and for best results about 160.degree. to
165.degree. F. (71.1.degree. to 73.9.degree. C.). Higher
temperatures are preferred since higher temperature increase the
effectiveness of the peroxide. However, excessively high
temperatures are undesirable since exposure of the grain to these
higher temperatures can adversely heat denature their proteins.
[0031] The amount of peroxide employed depends upon a variety of
processing parameters and desired level of bleaching. Due to the
cost of peroxide, the minimum amount required to accomplish the
desired level of bleaching is generally used.
[0032] To assist in the minimum consumption or usage of peroxide,
preferably, the peroxide solution can optionally additionally
further comprises a peroxide stabilizing agent. For example, sodium
silicate (at about 1%) and/or magnesium sulfate (at about 0.1%).
Also, the peroxide solution can further optionally additionally
include a chelating agent such as ethylenediaminetetraacetate
("EDTA") can optionally be added to remove any metal ions which may
otherwise bind to destroy the peroxide.
[0033] Still another optional ingredient in the peroxide solution
is a conventional deforming agent (e.g., about 0.1% to 1%).
Addition or inclusion of a defoaming agent is desirable to minimize
the generation of any foaming caused by any gas evolution that
occurs during the peroxide treatment step. The presence of a
defoaming agent is especially useful when a CO.sub.2 gas generating
alkaline material is employed such as sodium bicarbonate as further
described herein. Gas foaming is mildly undesirable in processing
commercial quantities of grain.
[0034] The amount of hydrogen peroxide can vary depending upon the
efficiency of the process parameters and the degree of bleaching
desired. Good results are obtained when the weight ratio of
hydrogen peroxide to flour ranges from about 1 to 5 parts to 100
parts grain.
[0035] The treatment step can be practiced by, for example,
applying an aqueous solution of hydrogen peroxide to the grain
kernels. This application can be practiced by immersing the grain
into an aqueous bath or great excess of peroxide solution. To
reduce the consumption of peroxide, the application step is
preferably practiced by wetting the grain or applying only enough
peroxide solution to coat the grain surfaces. A preferred technique
for practicing this wetting variation of the application or
treatment step is to spray the peroxide solution onto the grain,
preferably with agitation or movement of the grain.
[0036] In one embodiment the method of the present invention
generally involves a step B of treating the wheat kernels with an
alkaline solution, optionally drying the wheat kernels and
subsequently practicing the step A of treating them with the
peroxygen solution.
[0037] In this embodiment, step B preferably involves wetting the
wheat kernels with an alkaline solution. Alkaline solutions of 1%
to saturated having approximate temperatures of 50.degree. to
165.degree. F. preferably 130.degree. to 165.degree. F. and most
preferably 160.degree. to 165.degree. F. can be used in the
process, particularly when applied to the wheat kernels. Any food
grade alkaline material can be used including sodium carbonate,
sodium bicarbonate, sodium hydroxide, potassium hydroxide and
mixtures thereof. The preferred method utilizes food grade sodium
hydroxide, sodium carbonate or sodium bicarbonate.
[0038] The alkaline treatment solution can comprise from about 1%
to about 10% of the alkaline material. When applied as a separate
treatment step, sufficient amounts of the alkaline solution are
applied to thoroughly wet the surface of the grains. Good results
are obtained in this treatment of wetting step when about 10% to
15% of the alkaline solution are applied to a the wheat or other
grain kernels. That is about 10-15 kilogram of alkaline solution
for every 100 kg of grain.
[0039] The duration of the alkaline treatment step is short and
just long enough for the alkaline solution to infuse the outmost
bran layers yet minimize infusion into the endosperm. Good results
are obtained when the treatment step range from about 30 seconds to
about five minutes, preferably about 30 seconds to about three
minutes.
[0040] In a preferred embodiment, the alkaline treatment step B is
practiced by applying or wetting the grain by spraying.
[0041] In those less preferred embodiments wherein the grain is
added to a bath or an excess of the alkaline solution, the alkaline
solution wetted wheat are next preferably allowed to drain and to
dry e.g., drip dry.
[0042] After drying, the alkaline treated grain kernels can then
treated with or again wetted using a peroxygen compound. Hydrogen
peroxide is most preferred for economic reasons.
[0043] Peroxygen concentrations of 10-40% work particularly well in
the process when applied to the wheat temperatures of approximately
50.degree. to 165.degree. F. for durations of between 30 seconds to
3 minutes. Although bleaching will be successful when the wheat are
treated with peroxygen solutions having temperatures greater than
165.degree. F. or higher, higher temperatures should preferably be
avoided with longer contact time to prevent protein
degradation.
[0044] In the most preferred embodiment the alkaline solution and
the hydrogen peroxide solution are admixed and immediately
thereafter applied thus simultaneously to the grain kernels. In a
preferred variation, the treatment step is practiced with added
heating especially with microwave heating. On an industrial scale
practicing of the present methods, microwave heating may not be
economical.
[0045] When the peroxygen solution is applied to the alkaline
treated wheat, the peroxygen and the alkaline solutions undergo a
chemical reaction. The first wetting step causes the alkaline
solution to slightly saturate the outer bran layer (and hopefully
not the interior endosperm) during the first wetting step, so that
applying the peroxygen solution to the wheat causes the chemical
reaction between the two solutions to occur directly on the
exterior of the grain the reaction it is believed causes the
formation of an alkaline hydroperoxide radical, which is a
bleaching agent that causes the color in the bran. Because this
reaction occurs on the surface of the kernel, the full magnitude of
the reaction is utilized in bleaching the bran.
[0046] When an alkaline material is used that generates CO.sub.2,
the reaction of the peroxygen and alkaline solutions forms and
liberates a burst of gas bubbles. If residues such as soil, ground
mould, or bacteria such as aflotoxins are present on the grain
kernels the treatment beneficially tends to clean or reduce the
degree of contamination.
[0047] The concentrations, temperatures, and wetting times
described above are preferred ranges. For both the peroxygen
solution and the alkaline solution, many different combinations of
concentration, temperature, and wetting time will cause bleaching
of the bran or wheat kernels and these variables may be adjusted to
provide varying levels of whiteness of the treated wheat.
[0048] Wheat grain is a low cost commodity. At present, the cost of
peroxide per pound is about 10 times the price of wheat grain
treated. An advantage of using an alkaline treatment is to minimize
the amount of peroxide required to achieve the desired bleaching or
whitening effect. While peroxide treatment alone can be used to
practice the present grain treatment, the amount of peroxide
required to achieve desired levels of whitening of the grain are
high and thus costly relative to the amount required when an
alkaline pretreatment is employed. Also, surprisingly, the amount
of peroxide required is slightly less when the alkaline solution is
admixed with the peroxide solution immediately prior to application
only the grains.
[0049] If desired, the present methods can further include a rinse
washing step prior to the tempering step. Such a washing step can
remove any residual peroxide or alkaline material. Residual
alkaline material can impart an undesirable soapy flavor to the
finished flour.
[0050] For those sequential treatment variations, if desired, the
present methods can further include an intermediate drying step to
reduce all or a portion of the moisture added by the alkaline
solution treatment or wetting step.
[0051] The present methods can further optionally include a finish
acidic washing step. Increasing the amount of alkaline material
employed beneficially reduces the amount of peroxide required to
accomplish desired levels of bleaching. However, residual alkaline
material can result in the pH of the finished white sole wheat
flour from a conventional pH of about 6.3 to over 6.7. At such high
pH values, the baking and other functional properties of the four
can be adversely affected. The present optional methods are
desirably practiced so as to provide a whole wheat flour having a
pH of about 6.3 to 6.8, preferably about 6.3 to 6.7.
[0052] An unexpected advantage of the present invention is that
such surface treatment reduces the level of mold and other
bacteriological contamination of the grain. As a result, the
finished flour product can have lower levels of undesirable toxins
associated with mold growth.
[0053] Treatment of the bran while still an intact portion of the
grain kernels provides greater control over the bleaching process
and provides for easier physical manipulation than treatment of
bran in an isolated particulate form. In particulate form, the bran
tends to undesirably clump an is difficult to handle and to control
the treatment step.
[0054] As a result of treating, for example, red hard wheat, the
color of the resultant bleached grain kernel intermediate product
is similar to white hard wheat. Of course, white or hard wheat
grain is increasingly more widely available. However, even though
the visual appearance of the present bleached wheat is similar to
naturally colorless white hard wheat, the genetic profile of the
present bleached wheat still contains the color producing gene
alleles of red wheat.
[0055] Wheat kernels going into the tempering step generally have a
starting moisture content ranging from about 10% to 12%. The
tempering step generally involves steeping or admixing the grain
with water. The purpose of the tempering step is to both toughen
the outer bran coats for easier separation. The absorbed water also
softens or mellows the endosperm to facilitate the subsequent
breaking or milling operations. Generally, the tempering step is
conducted at ambient temperature. The tempering is continued for
times sufficient for the kernels to reach moisture contents ranging
from about 14% to 15%, preferably about 15% to 16%. While not
critical per se, good results are generally obtained when the
tempering step is practiced for holding times ranging from about
10-14 hours, preferably about 11-13 hours and for best results
about 12 hours.
[0056] The tempering step can be conveniently practiced utilizing
conventional drying apparatus and techniques.
[0057] Thereafter, the bleached and tempered grain kernels can be
milled in a conventional manner to provide whole grain flours. In a
preferred variation, the milling step is practiced to separate out
the germ fraction to provide a whole grain flour substantially
comprising only the bran and endosperm but not the germ
fraction.
[0058] The finished whole wheat flour provided herein has a color
and taste very similar to conventional white flour even though the
total dietary fiber content ranges from 8% to 12% preferably about
10% to 12% provided by the bran. The improved color is not only
readily visually apparent but also can be easily measured using
conventional colorometry equipment and techniques. The flour
preferably ranges in pH from about 6.3 to 6.7.
[0059] Still another unexpected advantage resides in the reduced
level of enzyme activity in the finished flour products prepared
from the present intermediate bleached grain kernels herein. For
those whole grain flower finished products that additionally
contain a germ fraction, such reduced enzyme activity levels is
especially beneficial in extending the shelf like of such flours.
Also, while not wishing to be bound be the proposed theory, it is
speculated herein that enzyme inactivation, particularly of
browning causing enzymes, is the mechanism responsible for the
resistance to browning during extended shelf storage at room
temperatures that some whole grain flows can experience.
[0060] Still another surprising advantage of the present invention
is that the present peroxide treatment while providing the benefit
of inactivating various enzymes does not result in gluten
inactivation such as can occur using a heat treatment for enzyme
inactivation.
[0061] Still another surprising advantage of the present invention
resides in the increase in gluten strength of doughs prepared from
flour products of the present invention. Gluten activity is
important to bread making and some batter applications such as for
muffins. Not only does the present enzyme inactivation benefit
occur without decreasing gluten strength, the present invention
actually provided gluten strengthening benefits. Subsequent
conventional flour treatment to increase gluten strength such as by
treatment with or addition potassium bromate can be minimized or
even eliminated. Thus, high gluten strength, bromate free whole
flour is provided.
[0062] Also provided herein are whole wheat flours of a high
quality taste and flavor that have enhanced gluten strength.
[0063] The present whitened high quality whole wheat flours can be
used to prepare a wide variety of finished grain based food
products. The flours can be used to prepare white whole grain
breads, pastries, baked goods (e.g., muffins, quick breads, layer
cakes), and griddle cakes such as pancakes. The whole grain flours
can be sold in bulk or in smaller quantities, e.g., 1 kg at retail
in conventional packages. The present whole grain flours can be
used as ingredients in dry mixes for such finished food products.
The present intermediate grain products and can be used in the
preparation of ready-to-eat cereals or grain based snack
products.
[0064] Even the mill feed byproducts of the present invention are
of higher value and quality by virtue of the reductions in color
and flavor. The present invention also can be used to provide
improved low fiber flour (1-2% dietary fiber) of improved quality
of even lower flavor and whiter color.
[0065] Thus since the invention disclosed herein may be embodied in
other specific forms without departing from the spirit or general
characteristics thereof, some of which forms have been indicated,
the embodiments described herein are to be considered in all
respects illustrative and not restrictive. The scope of the
invention is to be indicated by the appended claims, rather than by
the foregoing description, and all changes which come within the
meaning and range of equivalency of the claims are intended to be
embraced therein.
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