U.S. patent application number 11/363419 was filed with the patent office on 2006-06-29 for method for modifying ph within meat products.
This patent application is currently assigned to Freezing Machines, Inc.. Invention is credited to Eldon Roth.
Application Number | 20060141109 11/363419 |
Document ID | / |
Family ID | 32926743 |
Filed Date | 2006-06-29 |
United States Patent
Application |
20060141109 |
Kind Code |
A1 |
Roth; Eldon |
June 29, 2006 |
Method for modifying pH within meat products
Abstract
A method for injecting or forcing an ammonia-based pH modifying
material into the interior of a meat product to raise the pH at one
or more points within the interior of the meat product preferably
to a pH above approximately 6.0. The ammonia-based pH modifying
material may comprise aqueous ammonia (ammonium hydroxide solution)
or a gas including some ammonia gas fraction. The temperature of
the meat product may be controlled to a temperature near or just
below the initial freezing temperature of the meat product during
the time that the pH modifying material is injected. pH decreasing
materials may be injected into the interior of the meat product
either before or after injection the ammonia-based pH modifying
material.
Inventors: |
Roth; Eldon; (Dakota Dunes,
SD) |
Correspondence
Address: |
THE CULBERTSON GROUP, P.C.
1114 LOST CREEK BLVD.
SUITE 420
AUSTIN
TX
78746
US
|
Assignee: |
Freezing Machines, Inc.
|
Family ID: |
32926743 |
Appl. No.: |
11/363419 |
Filed: |
February 27, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10379761 |
Mar 5, 2003 |
7022361 |
|
|
11363419 |
Feb 27, 2006 |
|
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Current U.S.
Class: |
426/281 |
Current CPC
Class: |
A23L 13/72 20160801;
Y02A 40/946 20180101; Y02A 40/90 20180101 |
Class at
Publication: |
426/281 |
International
Class: |
A23L 1/31 20060101
A23L001/31 |
Claims
1. A method for treating meat, the method including: (a) inserting
a number of injection conduits into the meat at spaced apart
locations across substantially an entire area of the meat, each
injection conduit including a respective fluid communication
structure such that the step of inserting the number of injection
conduits into the meat positions the respective fluid communication
structure of each injection conduit within an interior of the meat;
and (b) forcing an ammonium hydroxide solution having a pH of at
least 8.0 through each respective injection conduit and fluid
communication structure into the interior of the meat.
2. The method of claim 1 wherein the ammonium hydroxide solution
has a pH in a range from 8.0 to 12.0.
3. The method of claim 1 further including forcing a buffer
material into the interior of the meat at a number of buffer
injection locations spaced apart across substantially the entire
area of the meat, the buffer material having a pH less than
8.0.
4. The method of claim 1 further including forcing a carbonic acid
solution in the interior of the meat at a number of carbonic acid
solution injection locations spaced apart across substantially the
entire area of the meat.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/379,761, filed Mar. 5, 2003, now U.S. Pat. No. ______. The
Applicant claims priority from this prior application under 35
U.S.C. .sctn.120. The entire content of this prior application is
also incorporated herein by this reference.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates to meat processing systems in which
fluids are injected into meat products. More particularly, the
invention relates to methods for injecting pH modifying materials
into meat products.
BACKGROUND OF THE INVENTION
[0003] Meat processing operations include a wide variety of
processing steps for preparing meat products for consumers. After
slaughter, the animal carcass is cleaned, chilled, and then passed
on to trimming operations in which large cuts of meat such as
steaks, roasts, and filets are separated from the carcass. Special
processing steps may be applied to the material left after the
initial trimming operations to recover additional lean meat from
the trimmings.
[0004] It may be desirable in some meat processing operations to
effect a change in the pH of the meat products by adding
appropriate pH modifying processing aids. For example, U.S. Pat.
No. 5,871,795 discloses a process for modifying the pH of meat
products using pH modifying gases, particularly ammonia gas and
carbon dioxide gas, for the purpose of reducing microbe counts in
the meat products. The pH modification disclosed in this patent is
accomplished by placing the pH modifying gas in contact with the
surface of the meat product at a pressure above the vapor pressure
of the gas at the temperature of the meat product.
[0005] The process described in U.S. Pat. No. 5,871,795 may be
applied to finely comminuted meat such as ground beef or to more
coarsely comminuted meat such as steaks, roasts, or filets. U.S.
Pat. Nos. 6,387,426 and 6,142,067 both disclose other processes for
applying a pH increasing materials to meat. The process disclosed
in U.S. Pat. No. 6,387,426 is suited particularly for treating
larger cuts of meat, while the process disclosed in U.S. Pat. No.
6,142,067 is suited only for treating finely comminuted meat such
as ground beef.
[0006] The prior pH treatments described in U.S. Pat. Nos.
5,871,795, 6,142,067, and 6,387,426 apply the pH modifying agent at
the surface of the material being treated. For example, the
treatments disclosed in U.S. Pat. Nos. 5,871,795 and 6,142,067 for
finely comminuted or ground meat products apply the pH modifying
material to the surface of the individual pieces of comminuted
meat. The processes then increase the pressure on the meat product
and pH increasing material and/or further comminute the meat
product to distribute the pH modifying material. For larger or more
coarsely comminuted cuts of meat such as steaks, roasts, or filets,
the prior pH modification process shown in U.S. Pat. No. 6,387,426
applies the pH modifying material to the surface of the meat and
then drives the pH modifying material into the meat by increasing
the pressure on the meat.
[0007] The systems and methods set out in the above-described
patents are effective for modifying the pH at the surface of the
meat product and somewhat below the surface. Surface pH
modification was emphasized because microbes are generally only
present at the surface of the meat, and the purpose of the pH
modification was mostly to reduce microbe counts. The prior pH
modifying systems were generally not as effective at modifying the
pH of the meat product beyond a thin surface layer on each
respective piece of meat. Thus, the interior areas of larger cuts
of meat such as steaks, roasts, filets, and larger carcass portions
remain generally unaffected by the prior art pH treatments.
SUMMARY OF THE INVENTION
[0008] The present invention encompasses methods for injecting or
forcing an ammonia-based pH modifying material into the interior of
a meat product. Adding the ammonia-based pH modifying material into
the interior of the meat product preferably raises the pH at one or
more points within the interior of the meat product to a pH above
approximately 6.0. As used in this disclosure in the accompanying
claims, an ammonia-based pH modifying material may be any material
that, when added to a meat product, results in an ammonium
hydroxide solution in the meat product. One preferred ammonia-based
pH modifying material comprises aqueous ammonia (ammonium hydroxide
solution). In the case of ammonium hydroxide solution, the desired
solution is produced within the interior of the meat product
directly as the ammonia-based pH modifying material is added.
Another preferred ammonia-based pH modifying material comprises a
gas including some ammonia gas fraction. In the case of ammonia
gas, the desired ammonium hydroxide solution is produced in the
meat product as the ammonia gas goes into solution in moisture
associated with the meat product.
[0009] In some forms of the invention, a buffering material may be
injected into the interior of the meat product either before,
during, or after injecting the ammonia-based pH modifying material.
Such a buffering material may be particularly useful when the pH
modifying material comprises ammonia gas or a concentrated ammonium
hydroxide solution.
[0010] A meat product treatment method according to the invention
preferably includes inserting an injection conduit or needle into a
meat product so that an opening or other fluid communication
structure associated with the injection conduit is positioned
within the interior of the meat product. Once the injection conduit
is properly positioned within the interior of the meat product, the
desired ammonia-based pH modifying material may be forced through
the injection conduit and into the interior of the meat product
through the fluid communication structure. Alternatively to
openings such as those in hypodermic needles, the fluid
communication structure associated with the injection conduit may
include one or more sections of porous and permeable material
through which the desired ammonia-based pH modifying material may
flow in response to a suitable driving pressure.
[0011] Once the ammonia-based pH modifying material is injected
into the interior of the meat product, the meat product may be
physically manipulated to help distribute the pH modifying material
within the meat product. This manipulation may comprise increasing
the pressure on the surfaces of the meat product or tumbling or
massaging the meat product in a suitable device. The insertion and
removal of the injection conduits also provide some manipulation to
the meat product.
[0012] In addition to injecting the ammonia-based pH modifying
material into the interior of a meat product, forms of the
invention may also include the step of injecting a suitable pH
decreasing material into the interior of the meat product. This pH
decreasing material may be injected through the same injection
conduit used to inject the ammonia-based pH modifying material, or
may be injected through a separate fluid injection device
comprising an additional injection conduit and fluid communication
structure associated with the additional injection conduit.
Regardless of the manner in which the pH decreasing material is
injected, the preferred pH decreasing material includes carbon
dioxide gas or a solution of carbon dioxide gas dissolved in water
(carbonic acid solution). Also, it should be noted that in forms of
the invention in which pH increasing and pH decreasing materials
are to be injected, either material may be injected first followed
by the remaining material. The pH increasing and pH decreasing
materials may also be injected simultaneously through separate
injection conduits.
[0013] One preferred form of the invention includes controlling the
temperature of the meat product during the step of forcing or
injecting the ammonia-based pH modifying material into the interior
of the meat product. In particular, the invention includes
maintaining the temperature of the meat product during injection at
a temperature just above or perhaps even below the initial freezing
temperature of the meat product, that is the temperature at which
ice crystals begin to form in the meat product. The method may
further include using an ammonium hydroxide solution as the
ammonia-based pH modifying material and maintaining the temperature
of the solution just above or even at or below the initial freezing
temperature of the meat product during the step of forcing or
injecting the material into the interior of the meat product. This
temperature control of the meat product and the ammonia-based pH
modifying material at the time of the injection increases the
ability of the meat to hold the pH modifying material. Temperatures
below the initial freezing temperature of the meat also allow the
pH modifying material to be held in the meat product without
immediately going into solution in the moisture within the meat
product. Rather, the ice crystals in the meat product and injected
pH modifying material may remain in the meat product until the
temperature of the meat product is increased to the temperature at
which the ice crystals melt. Only at this time does the pH
modifying material combine with the previously solidified water in
the meat product to increase the pH within the interior of the meat
product.
[0014] A treatment system embodying the principles of the invention
may include a temperature control arrangement to provide the
preferred temperature control of the meat product and the pH
modifying material being injected into the meat product. The
temperature control arrangement may include a prechilling device to
refrigerate the meat products to the desired temperature before
entering the injection device. A post-injection chilling device may
also be included in the treatment system for controlling the
temperature of the meat product after the desired injection. In
some forms of the invention the post-injection chilling device may
be operated to reduce the temperature of the meat product further
below the initial freezing temperature of the meat product after
the step of forcing the ammonia-based pH modifying material into
the interior of the meat product.
[0015] The present invention effects a pH change within the
interior of the meat product being treated. This pH change in the
interior of the meat product may be performed without affecting the
pH at the surface of the meat product. However, if a pH
modification is desired at the surface of the meat product,
additional processes such as those described in U.S. Pat. Nos.
5,871,795 or 6,387,426 may be used in addition to the treatment
according to the present invention.
[0016] These and other advantages and features of the invention
will be apparent from the following description of the preferred
embodiments, considered along with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a diagrammatic representation of a treatment
system for injecting ammonia-based pH increasing materials into the
interior of a meat product according to the present invention.
[0018] FIG. 2 is a diagrammatic representation of an injection
apparatus that may be used to perform methods embodying the
principles of the invention.
[0019] FIG. 3 is an enlarged section view showing an end portion of
an injection conduit that may be used in the apparatus shown in
FIG. 2.
[0020] FIG. 4 is a section view similar to FIG. 3, but showing an
alternate injection conduit structure.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] The system 10 shown diagrammatically in FIG. 1 may be used
to describe treatment methods embodying the principles of the
present invention. FIG. 2 shows further details of an injection
device 11 that may be used in performing certain steps of the
invention, while FIGS. 3 and 4 show alternate injection conduits or
needles that may be used in the present treatment methods.
[0022] Referring to FIG. 1, treatment system 10 includes injection
device 11 connected to receive treatment materials from a treatment
material supply arrangement 14. The illustrated treatment material
supply arrangement 14 in FIG. 1 includes three separate material
supplies, a supply 17 of pH increasing material, a supply 18 of
buffer material, and a supply 19 of pH decreasing material.
Treatment system 10 also includes one or more chilling or
temperature control devices that together make up a temperature
control arrangement for the meat product being treated in the
system. The diagrammatic example system 10 shown in FIG. 1 includes
two separate devices that make up the temperature control
arrangement, a prechilling device 22 and post-injection chiller 24.
Treatment system 10 further includes a manipulating device 25
positioned to receive meat products after the desired injection of
treatment materials.
[0023] Ejection device 11 operates to inject the desired treatment
material or materials into the interior of a meat product held in
the device. The injection will commonly require inserting an
injection conduit or needle into the interior of the meat product
to an inserted position. In this inserted position a fluid
communication structure or opening in the injection conduit is
positioned within the interior of the meat product so that the
desired treatment material may be forced through the conduit and
into the interior of the meat product. Further detail regarding
injection device 11 will be described below with reference to FIGS.
2 and 3.
[0024] Each of the material supplies 17, 18, and 19 may include a
suitable vessel for containing a supply of the desired material.
For example, pH increasing material supply 17 may include a vessel
containing ammonia gas or aqueous ammonium (ammonium hydroxide
solution). To facilitate some forms of the invention, two separate
vessels may be used for pH increasing material supply 17, each
separate vessel storing a different pH increasing material. In any
event, pH increasing material supply 17 is connected to injection
device 11 with at least one suitable connection line or conduit 17a
to supply the desired material or materials to the injection device
to be injected into the meat being treated in the system. It will
be appreciated that the material to be injected must be forced into
the meat being treated. The pH increasing material may be
pressurized to provide the required injection force at supply 17,
at injection device 11, or by a suitable device connected between
supply 17 and injection device 11.
[0025] pH decreasing material supply 19 may include a vessel
suitable for containing a pH deceasing material such as carbon
dioxide gas or carbon dioxide in solution with water (carbonic acid
solution). As with pH increasing material supply 17, the supply 19
may in fact include more than one vessel with each vessel
containing a different pH decreasing material. Regardless of the
number of vessels which make up supply 19, the supply is connected
by one or more suitable conduits or lines 19a to supply the
material or materials to injection device 11. The driving force for
forcing the pH decreasing material or materials into the meat
product being treated may be provided in any of the ways described
above with reference to the pH increasing material supply 17.
[0026] Buffer material supply 18 may include a vessel or multiple
vessels containing water, dilute ammonium hydroxide solution, or
any other material that may be used with the pH increasing or
decreasing materials according to the present invention. At least
one suitable connection conduit or line 18a connects buffer
material supply 18 to injection device 11. As with the other
material supplies 17 and 19, the force for driving the buffer
material into the meat product may be provided from the supply
itself, at the injection device 11, or using a suitable pumping
device connected in the supply line 18a extending from supply 18 to
injection device 11.
[0027] It will be appreciated that although three separate
connection lines are shown in FIG. 1 from supplies 17, 18, and 19,
some forms of the invention may include a manifold capable of
switching between the different supplies. Such a manifold would
receive inputs from each material supply and include a suitable
arrangement of valves for switching between these inputs and
provide an output directed to injection device 11. The present
invention is not limited by any particular structural arrangement
for supplying the desired pH modifying materials to injection
device 11 for injection into the meat products being treated.
[0028] Although the supplies 17, 18, and 19 are described above as
including one or more vessels containing the desired material, a
system for providing the treatment according to the invention may
eliminate supply vessels. In these systems any solutions or
mixtures to be injected into the meat products may be produced
continuously as the material is directed to injection device 11.
For example, ammonia may be sparged into a stream of water to
produce an ammonium hydroxide pH increasing solution. Carbon
dioxide gas may be sparged into a stream of water to produce a
carbonic acid pH decreasing solution. These supply arrangements are
to be considered equivalent to the supply arrangements including
holding vessels for holding supplies of the desired materials to be
injected.
[0029] Injection fluid temperature control device 20 shown in FIG.
1 operates to control the temperature of the treatment material
injected into the meat products through injection device 11. The
nature of temperature control device 20 will depend upon the nature
of the material being injected. In some forms of the treatment
system, temperature control device 20 may comprise a chiller
through which the different materials from supplies 17, 18, and/or
19 may be circulated to maintain the materials at the desired
temperatures. Temperature control device 20 may comprise a single
chilling device for chilling materials from each of the supplies
17, 18, and 19, or separate chilling devices for each supply.
[0030] Prechiller device 22 shown in FIG. 1, operates to place the
meat products at the desired process temperatures required in the
treatment methods according to the present invention. The single
device shown as prechiller 22 may actually include a number of
separate refrigerating devices. For example, a prechiller may
include a freezer for reducing the temperature of the meat products
to a temperature well below the initial and final freezing
temperature of the meat products, and then one or more separate
tempering devices for tempering the meat product to a temperature
at or just above or below the initial freezing temperature of the
meat product. Alternatively, a single prechilling device 22 may
place the meat products at the desired temperature for performing
the material injection or injections according to the present
invention.
[0031] Post-injection chiller 24 may be included in treatment
system 10 for controlling the temperature of the meat products
after injection with the desired materials in injection device 11.
Post-injection chiller 24 may be placed before any manipulating
device included in the system such as manipulating device 25 as
shown, or after the manipulating device in the process flow. In any
case, post-injection chiller 24 may include any suitable
refrigerating device for controlling the temperature of the
injected meat products within the desired temperature range. This
range may include temperatures well below the initial and final
freezing temperature of the meat being treated.
[0032] Manipulating device 25 is arranged to receive meat products
after they have been injected with the desired materials in
injection device 11. The device may include a massaging device or
tumbler for physically working with the meat products to help
distribute the pH increasing and other injected materials
throughout the interior of the meat products. Manipulating device
25 may alternatively include a chamber in which the injected the
products are placed and subjected to elevated pressures. It will be
appreciated that in systems 10 in which the meat is frozen when it
leaves injection device 11, manipulation of the meat product may be
undesirable in some situations, and thus the manipulating device
may be omitted from the system. However, some manipulation in the
meat product may be desirable even if the meat product is in a
frozen or partially frozen state.
[0033] Referring now to FIG. 2, a suitable injection device 11 may
include two separate injection stations shown at dashed boxes 31
and 32, and a conveyor 34 for conveying meat products through the
device. First injection station 31 includes a first injector 35
having a number of injection conduits or needles 36 extending from
a common injector block 37 which is connected to a treatment
material supply line 38. It will be appreciated that injector block
37 includes fluid passages that direct treatment fluid from the
supply line 38 to the injection conduits 36. Injector block 37 is
mounted on a manipulating structure 39 that may be operated to move
the block 37 from an upper position shown in solid lines to a lower
or injection position shown in phantom lines, and then back to the
upper position. In the injection position of block 37, injection
conduits 36 are pressed into the meat product 40 to the inserted
position in which the desired treatment material may be injected
into the interior of the meat product.
[0034] Second injection station 32 includes a second injector 45
having injection conduits or needles 46 depending from a injector
block 47. A second supply line 49 connects to block 47 for
supplying treatment material to the block to be distributed through
fluid passages in the block to injection conduits 46. As with the
first injector 35, second injector 45 is connected to a
manipulating structure 49 which may be operated to move block 47
and injection conduits 46 between an upper position shown in solid
lines and a lower, injection position shown in phantom lines. In
the injection position, injection conduits 46 are pressed into the
meat product 40 to an inserted position in which the desired
treatment material may be injected through the injection conduits
into the interior of meat product.
[0035] Both sets of injection conduits or needles 36 and 46 extend
through openings in a plate 52. Plate 52 defines an upper boundary
for the path the meat products 40 take through injection device 11.
This upper boundary separates the meat products 40 from the upper
components of injection device 11. The upper boundary provided by
plate 52 also helps define an area or tunnel in the injection
device 11 that helps isolate the meat products being treated so as
to help maintain the temperature of the meat products as they pass
through injection device 11.
[0036] In operation, the meat product 40 to be treated is first
conveyed to first station 31 and to a position immediately beneath
injection conduits 36 carried by injector block 37. Meat product 40
is held in this position while injector block 37 and injection
conduits 36 are lowered on manipulating structure 39 until the
injection conduits 36 reach an inserted position in which the
distal ends of conduits 36 extend into the interior of meat product
40. In this inserted position, an opening or fluid communication
arrangement associated with each injection conduit 36 is positioned
in the interior of meat product 40. Treatment material may then be
pumped or otherwise forced through supply line 38, fluid passages
in block 37, and the injection conduits into the interior of meat
product 40. After the desired amount of treatment material has been
forced into the interior of meat product 40, the flow of treatment
fluid through injection conduits 36 maybe stopped and manipulating
structure 39 operated to lift block 37 up to withdraw the injection
conduits from meat product 40. With injection conduits 36 withdrawn
from meat product 40, conveyor 34 may be driven with a suitable
drive (not shown) to move the meat product to second station 32.
Injector 45 at second station 32 may be operated similarly to
injector 35 to inject additional treatment fluid into meat product
40. Once any second or additional injection is complete, meat
product 40 may then be conveyed out of injection device 11.
[0037] It will be appreciated that the injection conduits 36 and 46
may not be maintained in a static inserted position in the meat
product 40 while material is injected. Some injection conduits,
especially those that inject only through an end of the conduit,
may be manipulated to different inserted positions in the meat
product by the respective manipulating structure in order to allow
the pH modifying material to be injected at different depths in
meat product 40.
[0038] The supply conduits 38 and 48 to the two injectors 35 and
45, respectively, may each be connected to a respective single
supply of treatment material. For example, the first injector 35
may be used to inject an ammonia-based pH modifying material such
as aqueous ammonia or a gas mixture including ammonia gas. Second
injector 45 may be used to inject a pH deceasing material such as
carbon dioxide gas or carbonic acid solution. Alternatively to the
fixed supply arrangement, each supply conduit 38 and 48 may be
connected to a number of supplies for different types of treatment
materials controlled through a suitable manifold (not shown). This
multiple supply connection allows for example, a buffer material
such as water to be injected first into a meat product and then an
ammonia-based pH modifying material such as ammonia gas through the
same injection conduits. As yet another alternative, a buffer
material may be injected through first injector 35 and an
ammonia-based pH modifying material such as ammonia gas may be
injected through second injector 45 or even a third or further
subsequent injector (not shown in FIG. 2).
[0039] FIG. 3 provides an enlarged section view of a distal end of
a preferred structure for injection conduits 36 and 46 shown in
FIG. 2. The injection conduit includes a tube portion 54 having an
opening 55 extending there through. The tube 54 terminates at an
end defined by a plane P extending at a steep angle to the
longitudinal axis of the tube. This structure provides a sharp
pointed end 56 to the injection conduit. Although the end of tube
54 may simply be left open to provide a fluid communication
arrangement for allowing treatment fluid to flow through the
injection conduit, the illustrated injection conduit includes a
plug of porous and permeable material 58 positioned in tube opening
55 at the end of the tube 54. This porous and permeable material is
cut along the same plane P as the tube, and facilitates better
control of fluid flow through tube opening 55 into the meat
product. Examples of suitable porous and permeable materials
include sintered metals such as the sintered materials produced by
Mott Corporation of Farmington Conn.
[0040] FIG. 4 shows an alternate injection conduit that may be used
in the present invention. In this alternate structure, the
injection conduit includes a base tube portion 60 and an injection
tube portion 61. At least a portion of the injection tube portion
61 is made up of porous and permeable material such as the material
shown at 58 in FIG. 3. The material to be injected flows from the
interior 62 of injection tube portion 61 through the porous and
permeable material of fluid communication structure. This
alternative injection conduit and fluid communication structure has
the advantage that the pH modifying material flows into the meat
all along the porous and permeable material, which, as shown in
FIG. 4, may extend far up the side of the conduit. This ability of
the pH modifying material to flow into the meat through essentially
the sides of the injection conduit allows the material to be
injected at different depths in the meat without having to adjust
the depth to which the conduit is inserted into the meat.
[0041] The injection conduit structure shown in FIG. 4 includes a
conical pointed end 64 to facilitate inserting the conduit into the
meat product to be treated. This type of pointed end is shown only
for purposes of example. Alternate forms of injection conduits
having porous and permeable side sections may be formed with a
steeply angled planar end similar to the planar end of the conduit
shown in FIG. 3. Also, other forms of the injection conduit may
include a solid material tip or point and porous and permeable
material along the sides of the conduit or portions of the
conduit.
[0042] The preferred methods of treating meat products may be
described with reference to the apparatus shown in FIGS. 1 through
3. One preferred treatment method includes inserting the injection
conduits 36 or 46 shown in FIG. 2 into meat product 40 to the
inserted position described above. The method then includes forcing
an ammonia-based pH modifying material through the injection
conduits 36 or 46 into the interior of meat product 40. Sufficient
ammonia-based pH modifying material is preferably forced into the
interior of meat product 40 to increase the pH at one or more
points within the interior of the meat product to a pH of
approximately 6.0 and perhaps to as high as 7.5 or higher.
[0043] It will be appreciated that the amount of pH modifying
material required to produce the desired final pH in the meat
product will depend upon a number of factors including the
concentration of the pH modifying material, the initial pH of the
meat product, and the temperature of the meat product. Ammonium
hydroxide solutions having a pH from 8.0 to 12.0 may be used to
produce the desired pH change in the meat. Where the pH modifying
material includes ammonia gas, ammonia gas may be used in
substantially pure form or may be mixed with other gasses such as
nitrogen, helium, argon, or carbon dioxide gas.
[0044] After or before injecting the ammonia-based pH modifying
material into the interior of meat product 40, the present
invention may also include the step of forcing a pH decreasing
material into the interior of the meat product. This pH decreasing
material, such as carbon dioxide gas or carbon dioxide in solution
with water, may be injected through the same injection conduits 36
used to inject the ammonia-based pH modifying material.
Alternatively, the treatment method may include inserting the
second injection conduits 46 into the meat product 40 to the
inserted position. The step of forcing the pH decreasing material
into the interior of the meat product may then be accomplished
through this second set of injection conduits or needles 46.
[0045] After the step of injecting the ammonia-based pH modifying
material or the pH decreasing material, or after each injection
step, the invention may include physically manipulating the meat
product 40 to distribute the injected materials within the meat
product. This physical manipulation may be through any suitable
manipulating device (25 in FIG. 1), such as a massaging or tumbling
device, or a pressurizing device.
[0046] An important aspect of the present invention relates to the
temperature of meat product 40 at the time of injecting the
treatment material, and especially the ammonia-based pH modifying
material. In a preferred form of the invention, the temperature of
the meat product 40 in FIG. 2 is controlled to temperature just
above, or at or just below, the initial freezing temperature of the
meat product and maintained at this temperature during the step of
forcing the ammonia-based pH modifying material into the interior
of the meat product. For example, meat products may be maintained
at a temperature of no greater than about 35 degrees Fahrenheit
during the pH modifying material injection.
[0047] Where the ammonia-based pH modifying material comprises
ammonium hydroxide solution, the invention may further include the
step of maintaining the temperature of the ammonium hydroxide
solution at or below the initial freezing temperature of meat
product 40 during the step of forcing the material into the
interior of the product. The meat product temperature may also be
reduced further after forcing the ammonia-based pH modifying
material into the interior of meat product 40.
[0048] Controlling the temperature of meat product 40 to a
temperature just above the initial freezing point of the meat
product allows the meat to more readily take or absorb the pH
modifying material. Controlling the temperature of the meat product
40 to a temperature at or below the initial freezing temperature of
the meat product during the injection step allows the pH modifying
material to be injected without immediately going into solution in
the moisture contained in the meat product. Rather, the injected pH
modifying material remains unabsorbed in meat product 40 while the
product remains frozen, and goes into solution in the original
moisture in the meat product only after the temperature of the meat
product is raised to a temperature above the freezing point of the
meat. Alternatively, the pH modifying material may be injected
while the meat temperature is above the initial freezing
temperature and then the temperature of meat product 40 may be
reduced quickly during the pH modifying material injection step or
immediately thereafter to freeze the meat product and arrest the
distribution of pH modifying material into the moisture of the meat
product. The pH modifying material may then continue to distribute
through the meat product only after the temperature of the meat
product is increased above the freezing point.
[0049] Ammonia gas or aqueous ammonia comprise the preferred
ammonia-based pH modifying materials. Where ammonia gas is used as
a pH modifying material, it may be necessary or desirable to dilute
the gas with other gasses in order to prevent the meat from being
over treated. Alternatively or in addition to diluting the ammonia
gas concentration in the treatment material, a method according to
the invention may include injecting a buffering material into the
interior of any product prior to forcing the ammonia gas intending
interior of any product. A suitable buffering material may comprise
water, dilute ammonium hydroxide solutions (having a pH below about
8.0), or perhaps carbon dioxide gas or dilute carbonic acid
solutions, or any other material suitable for buffering the pH
increasing material in the meat product and tying up ammonia that
does not become tied up in the meat upon injection. Buffering with
these materials may also be useful or required when using a highly
concentrated solution of ammonium hydroxide as the pH increasing
material. Buffering material may also be sprayed onto the surface
of the meat product before, during, or after injecting with pH
modifying material to help absorb or neutralize excess pH modifying
material.
[0050] As used herein, whether in the above description or the
following claims, the terms "comprising," "including," "carrying,"
"having," "containing," "involving," and the like are to be
understood to be open-ended, that is, to mean including but not
limited to. Only the transitional phrases "consisting of" and
"consisting essentially of," respectively, shall be closed or
semi-closed transitional phrases, as set forth, with respect to
claims, in the United States Patent Office Manual of Patent
Examining Procedures (Eighth Edition, August 2001 as revised May
2004), Section 2111.03.
[0051] Use of ordinal terms such as "first," "second," "third,"
etc., in the claims to modify a claim element does not by itself
connote any priority, precedence, or order of one claim element
over another or the temporal order in which acts of a method are
performed, but are used merely as labels to distinguish one claim
element having a certain name from another element having a same
name (but for use of the ordinal term) to distinguish the claim
elements.
[0052] The above described preferred embodiments are intended to
illustrate the principles of the invention, but not to limit the
scope of the invention. Various other embodiments and modifications
to these preferred embodiments may be made by those skilled in the
art without departing from the scope of the following claims.
* * * * *