The invention relates to the injection into "flesh" section of flesh
foods of a suspension of flesh solids in a liquid, and in particular to an apparatus
for the injection of such a suspension and a method of injection of such a suspension.
The processing of various flesh products, including meat and fish,
involves the injection of mixtures and solutions, such as salt brine, and pickle
for preserving, flavouring and curing such products. Typical such products includes
hams, picnics, bacon, shoulders, briskets, and any other products which may be
injected with liquids from time to time. Such products may be pork, beef, poultry,
or, for example, fish products, which are being further processed after dressing,
cleaning, and chilling. All such injectable products are termed herein as "meat"
whether the same includes any type of meat or poultry or fish.
The process of injection involves the insertion of a plurality of
elongated injection needles into a meat section, after the liquid is pumped into
the meat. It is well known that this process leaves markings in the meat if the
diameter of the needles is large and their spacing and orientation is regular,
and when the meats are sliced for consumption, these markings appear as visible
It is also known in the meat processing industry that in order to
make use of the trim portions of lean meat, such trim portions may be finely ground
and emulsified with a liquid. The emulsion is then used for making sausage products
such as hot dogs, bologna, weiners, frankfurters, and the like.
In an attempt to alleviate the problem of markings and blemishes
in meat sections resulting from the pickle or brine injecting process, it has been
proposed to make a mixture of such a meat emulsion, similar to that used in sausage
products, with a pickle or brine, and to inject this mixture into the meat sections.
The proposal has not been entirely successful, and injection marks and blemishes
are still visible.
Meat emulsions are in the form of a smooth cream in texture, in which
the meat particles are so fine that it is impossible to distinguish them. By definition,
the fine meat particles form a continuous phase in this mixture encapsulating
the fat and moisture in the matrix of soluble protein derived from the meat. When
injected into meat sections, i.e., muscle meat, the emulsion will still have the
texture and appearance of a paste, and is easily detected with the naked eye when
the product is sliced for consumption, so that the problem of blemishes is still
It has now been established that if, in place of the meat emulsion,
a mass of finely divided meat pieces (i.e., less than 2.0 mm in length) is suspended
in the pickle or brine where the aqueous phase is continuous, and the meat particles
are held in suspension within this aqueous phase, this suspension can be injected
into the meat sections in accordance with the process and apparatus disclosed
herein. When such meat sections are so injected, and processed for consumption
and sliced, needle marks or blemishes are no longer visible, and cannot be discerned
by the naked eye. Consequently they do not impair the appearance of the meat when
it is consumed.
An additional benefit of this process lies in the fact that, while
injection of brine or pickle mixtures assists in the curing of the meat sections,
and the flavouring of the meat sections, it essentially "dilutes" the actual weight
of the meat section. In other words, while a meat section weighing, for example
1000 grams, without injection of brine or pickle, and represents to the consumer
as a buyer at that stage 1000 grams of meat, a section of 1000 grams to which,
for example 300 grams (i.e., 30%) of brine or pickle mixture has been injected,
has a total weight of 1300 grams, but still represents to the processor purchased
meat of only 1000 grams. Consequently, when the consumer purchases a given quantity
of meat products processed with pickle or brine, at for example an injection rate
of 30%, the consumer is in fact receiving original muscle meat of approximately
1000/1300 x 100 = 76.9% of the total weight purchased.
This factor is, of course, well understood in the industry, and in
fact is carefully regulated by industry practice and government regulations. When,
however, such meat sections are injected with finely divided meat pieces, suspended
in the pickle or brine mixture, then the consumer is in fact receiving muscle meat,
additional to that contained in the actual meat section which is injected. Thus
the consumer is in effect receiving more value for money, in addition to receiving
a product which is more visually appealling when sliced and consumed, than a product
which is injected simply with the usual liquid mixture of pickle or brine.
This factor is advantageous to the processor for two reasons. In
the first place, the public will perceive the product as being more desirable than
a product injected in the conventional way with liquid brine, and will thus tend
the purchase the improved product rather than the unimproved product. In addition,
however, there is a further advantage to the processor, namely, that under the
old practice where the meat trimmings were ground and emulsified for making sausage
products, they resulted in a lower price being obtained for the product. However,
by the use of the invention, where such meat trimmings are finely divided and
are then incorporated in an injected product, then they will be fetching a somewhat
higher price, and consequently the process will have economic value to the processor
beyond the factor of the simply making the product more appealing. Such a suspension
is defined herein as a "cold milled particle reduction suspension", and in such
suspension the particles are less than 2.00 mm in any dimension.
Attempts to carry out this process using conventional injection needles
and pumps, designed for injecting conventional liquid pickle or brine mixtures
have been unsatisfactory. Conventional injection equipment consists simply of
a plurality of needles mounted on a moveable framework, which could be operated
automatically to repeatedly plunge the needles into the meat sections, while the
meat sections were moved progressively in stop-wise fashion past the needles. In
addition, such conventional equipment included a tank for holding the brine, and
a pump. However, it is found that when using this relatively simple equipment
to inject a suspension of meat pieces, the nature of the suspension of meat pieces
undergoes an irreversible change due to temperature rise. As a result, the suspension
turns into a jelly-like mass, in which condition it is impossible to handle, and
it is impossible to inject it, into meat sections.
In addition, conventional injection needles employ a design in which
the end of the needle is pointed, for ease of insertion, and in which a central
passageway down the interior of the needle, terminates in an opening adjacent
one side of the needle (i.e., the needle discharge port is radial drilled).
It is found that these needles are unsuitable for the injection process,
when operating with a suspension of meat pieces.
A further problem was encountered using conventional equipment in
that the suspension of meat pieces was found to be unsuitable for pumping through
conventional equipment, and modifications were required before the suspension
could be pumped satisfactorily at a constant pressure.
A further feature arising from the nature of the suspension was found
to arise from the fact that the suspension has a much greater resistance to flow
along a conduit than does a liquid pickle or brine, and the conduits, especially
the smaller diameter conduits leading to the injection needle, on conventional
equipment were found to create too much resistance to flow. In addition, conventional
equipment would become plugged with such suspension, and had to be repeatedly cleared
out to ensure free flow.
It is also found in practice that there is some degree of wastage
in the injection of the suspension, which will then cause less to the process.
Using conventional equipment this wastage could not be recovered.
It has also been established that even with the equipment designed
for optimum performance, the steps of injection were preferably carried out in
a certain manner and at a certain temperature range in order to achieve maximum
With a view to overcoming the various disadvantages of the process
noted above, the invention comprises apparatus for the injection of a cold milled
particle reduction suspension of finely divided meat pieces (less than 2.0 mm
in any dimension) in a liquid mixture, and comprising container means for receiving
a supply of said suspension, pump means on said container means for pumping said
suspension from said container means at a constant pressure of a set point of
between about 207 and about 620 kPa, (about 30 and about 90 psi, to header means,
a plurality of injection needles connected to said header means, said injection
needles defining axial passageways and openings at their free ends, and defining
points, on respective said needles, smoothly curved conduit means connecting from
said header means, to said passageways in said needles, and, valve means on said
header means for opening and closing all said conduit means simultaneously, said
salve means being normally closed prior to insertion and all being openable simultaneously
when at least some said needles enter said meat section, said pump means being
operable to pump said suspension of meat pieces through all said valve means and
all said injection needles at said pre-set pressure of between about 207 and 620
kPa (about 30 and about 90 psi), and at a temperature of between about 26°F and
42°F, whether said needles are located in a said meat section or not, and thereby
objecting said suspension from all said needles simultaneously.
The invention further provides apparatus as described, and further
including collector means for collecting excess suspension from around said meat
section, and an apparatus for returning same to said container for injection into
a further said meat section.
The invention further provides apparatus as described and further
including heat exchanger means for chilling said excess suspension to a temperature
of between 26°F and 36°F
The invention further provides an apparatus having the foregoing
features and including means for detecting the position of said needles, the depth
of injection into the meat sections, the pressure of said suspension during injection,
and means for varying the operation of said pump means, and means for detecting
the temperature of said suspension, whereby to maintain control over said temperature
and pressure of said suspension.
The invention also provides a method of injecting meat sections with
a suspension of finely divided meat particles by means of apparatus described above,
while maintaining predetermined temperature ranges, and percentages of suspension.
The various features of novelty which characterize the invention
are pointed out with more particularly in the claims annexed to and forming a part
of this disclosure. For better understanding of the invention, its operating advantages
and specific objects attained by its use, reference should be had to the accompanying
drawings and descriptive matter in which there are illustrated and described preferred
embodiments of the invention.
IN THE DRAWINGS
- Figure 1 is a schematic perspective showing a typical pickle injection apparatus;
- Figure 2 is a schematic side elevation of a portion of the apparatus of Figure
1 partially cut away;
- Figure 3 is a schematic end elevation, of the portion of the apparatus shown
in Figure 2, partially cut away;
- Figure 4 is a fragmentary perspective illustration of the apparatus of Figures
2 and 3, partially cut away;
- Figure 5 is an enlarged section along 5-5 of the injection portion of the apparatus
of Figure 4;
- Figure 6 is an enlarged perspective of a portion of an injection needle;
- Figure 7 is a schematic block diagram showing the controls of the principal
components of the apparatus, and,
- Figure 8 is a schematic diagram of a system incorporating the pickle injecting
In conventional pickle-injecting machines, injection needles are
forced into a section of meat, while a pump is operated to force the liquid brine
or pickle through the injector needles into the meat section.
The injector needles in the conventional type of brine injector equipment
consist of elongated tubular needles, having a solid point at the end, and having
an ejection opening formed or drilled in one side of the needle, close to the
end in a generally radical fashion. In this way, the needle has a sharp solid point
which can be readily forced into the meat section.
The injection machine has power means, e.g., hydraulic means for
operating the needles, and a pump for pumping the liquid. A tank alongside the
machine supplies the liquid.
In most meat processing plants, the various steps of dressing the
meat, and cutting it into cuts, and then removing the muscle meat or lean meat
for the formation of meat sections to be made into hams, for example, or the removal
of other meat sections such as separating the brisket from the remainder of the
carcass, result in almost all cases in the creation of small cuttings or trimmings
of relatively lean meat. In most meat processing facilities, such cuttings or
trimmings are then utilized in the production of other low value-added meat products
such as sausages. In many cases, such cuttings or trimmings are passed through
a meat grinder, and ground up as finely as possible and mixed with a liquid to
produce a meat emulsion, which is used in the production of sausage products such
as hot dogs, weiners, and bologna.
In accordance with the present invention, however, such lean meat
cuttings and trimmings will be processed cold in a cold reduction mill with an
aqueous pickle or brine solution of from two to six times the weight of said trimmings
so as to shred and divide the lean meat into finely divided meat pieces, wherein
the meat texture and fibre is still identifiable to the naked eye. The meat pieces
should be no larger than 2 mm in any direction. These meat pieces will then form
a suspension in such pickle or brine. The temperature of the suspension formed
should be chilled or maintained at a temperature between about 20°F to 26°F prior
to further use. It is then transferred to a tank or container for injection through
the injection apparatus into the meat sections.
In accordance with the invention, the invention provides a pickle
injector unit indicated generally as 10, having a main body portion 12, and a conveyor
portion 14, and an injector head 16. A plurality of needles 18 are mounted in
the injector head 16, and are described in more detail in connection with Figure
5. As shown in Figure 6, in accordance with the invention, the injection needles
consist of a tubular body 19, defining an axial passageway formed with an end
portion defining an offset point 20 to one side of said body, and a planar angled
oval perimeter 21, and an axial opening across the full extent of the cross-section
of said needle.
Needles 18 are mounted between an upper cross-frame 22 and a lower
cross-frame 22A, moveable with respect to upper cross-frame 22. Springs 23 are
provided for needles 18, so that they may be moved against the influence of the
springs relative to the lower cross-frame 22A by the upper cross-frame 22. The
upper cross-frame 22 is, in turn, connected to side rod 24s. Rods 24 are connected
by a cross-frame 26 to a cylinder 28. The operation of cylinder 28 will thus cause
the needles 18 to move downwardly and upwardly.
The injector needles are supplied with suspension by a transverse
header tube 29.
In accordance with a feature of the invention, individual semi-flexible
hoses 30, extend between nipples 31 on the header tube and the upper ends of the
needles. The hoses 30 are formed into smoothly regularly radiussed curves, so
as to provide a unobstructed flow path for the suspension.
A plurality of valves 32 are provided in the header, there being
one such valve for each set of two nipples or needles. The valves are normally
closed, and have spring-loaded stems 33 operable by a valve operating bar 34 which,
in turn, is open in unison with the action of the stripper plate 36.
In order to permit the needles to be withdrawn from the meat pieces,
the moveable stripper plate 36 is provided. The stripper plate 36 has a plurality
of holes 38 therethrough for receiving the needles. The stripper plate is moveable
downwardly by means of cylinder 28. The stripper plate 36 is moveable upwardly
by power-operated means such as cylinders 40 which are connected to shafts 41.
Cylinders 40, on their upward stroke, also function to close the valves 32, in
a manner explained below.
Cylinders 40 are essentially inoperative, but closed, on the downstroke
of cylinder 28. In this way, both the needles and the stripper plate descend in
unison, with valves 32 closed by bar 34. As the stripper plate engages a meat
section it stops. Cylinders 40 then open, permitting the needles to descend further
into the meat section. This causes the header 29 to move downwardly relative to
bar 34, thus opening all of the valves 32 in unison. This permits the pump to pump
the suspension through all of the valves 32, and all of the needles 18, whether
such needles 18 have been inserted into the meat sections or not.
After pumping, the cylinder 28 is operated to raise header 29 thus
withdrawing the needles from the meat section. However, during this stage cylinders
40 are operated to hold the stripper plate down.
In this way, the meat section may be held firmly by the stripper
plate, while the needles are removed.
Bar 34 remains stationary, as header 29 is raised. Thus valves 32
are closed as the needles are withdrawn. It will be understood that in fact several
meat sections will be placed on the conveyor at a time so that as many needles
as possible register with and discharge suspension into the meat sections.
It is however recognized, and it is a significant feature of the
invention, that in many cases not all of the needles will register with meat sections,
and will thus simply be open at their ends. Other needles may engage or encounter
pieces of bone in the meat sections and thus be unable to penetrate further, so
that they are at least partially open at their ends.
However, in accordance with the invention, the suspension is pumped
through all such needles in each stroke and in each cycle simultaneously, and some
suspension which simply discharged exteriorly of meat sections. This surplus suspension
will be collected and recycled in a manner described below.
This significant feature of the invention enables the injection apparatus
to pump and inject the suspension in a reliable and repeatable fashion, without
jamming or plugging of needles or their conduits.
In order to advance the muscle meat sections progressively to register
with the needles along conveyor portion 14, a moveable conveyor belt 42 is provided,
consisting of an open mesh chain or screen, which may be moved intermittendly,
by any suitable motor means 44 such is well known in the art, in a start-stop fashion
so as to progressively move sections of muscle meat to register with the needles.
In order to supply the suspension of finely divided meat pieces in
brine or pickle, a supply tank 46 is located exteriorly of main body 12, and is
provided with its own variable speed pump 48 driven by motor 50. A fixed conduit
52 connects with the main body 12, and from within the main body 12 (Figure 4)
a flexible conduit 54 extends upwardly through branch tubes 55 which connect to
the header tube 29, at each end.
In this embodiment, motor 50 is a variable speed motor, and can be
operated so as to control the speed of pump 48, and thus to regulate the pressure
of the suspension within the conduits 52 and 54.
A pressure transducer 56 is provided, connected, for example, to
conduit 54, whereby to constantly monitor the pressure of the suspension and to
provide feedback for the control motor 50.
In addition, a belt advance encoder 58 (Figure 4) is connected to
the motor 44 of the conveyor belt 42 whereby to determine the position of the conveyor
In order to determine the position of the injector head 16, a positional
encoder 60 is provided, engaging frame 28.
Suitable control valves (not shown) are provided for the motor 50,
motor 44, cylinder 27, and cylinders 40, whereby their operation can be controlled.
Such control valves are well known in the art and are omitted from this illustration
and description for the sake of clarity. They are referred to generally in the
block diagram of Figure 7.
Located beneath the conveyor is a collector tray 62 (Figure 3), intended
to receive and catch any excess suspension which may be exuded from the meat sections
or which is ejected by needles which do not register with or do not penetrate
a meat section. Tray 62 is connected by a drain conduit 64, to tank 66 (Figure
Tank 66 is connected to a pump 68, which is adapted to pass the re-cycled
suspension through an optional heat exchanger 70, to a tank 72. The tank 72 is
also adapted to receive brine and/or pickling liquid, via pipe 73. Typically the
brine (and/or pickle) will have been chilled, e.g., in a heat exchanger 73a, typically
to a temperature in the region of 18°F. The trim portions of meat M will have
been chilled or frozen separately, to in the region of 18°F in a separate chiller
(not shown) and are supplied via hopper 74 and pipe 74a. The tank 72 will thus
receive a mixture of fresh un-milled material, and recycled suspension, at a reduced
or chilled temperature.
The tank 72 is connected to a cold reduction mill 75, which is operable
to process both the fresh material and the recycled suspension, until the meat
particles are all reduced to the same size of not more than 2 mm in any direction,
forming a suspension in the brine.
From the mill, the suspension is then passed via a conduit 76, to
It will, of course, be appreciated that the volume of material draining
from the tray 62 to the tank 66 will vary, and thus operation of the pump 68 will
take place at intervals, depending upon the volume of material accumulating in
the tank 66. In a typical operation, the pump 68 will be operated intermittently,
and may be controlled, for example, by a float level switch 78 (Figure 8), in
During most of the operating time, the tank 72 (and thus tank 46)
will be receiving only fresh material.
In this way, excess suspension, which would otherwise be lost at
the injection needles, in collected and at intervals, is (optionally cooled), recycled,
and is remixed with the fresh chilled meat suspension for resupply to container
All of the above operations are controlled by means of a controller
80, containing logic circuits for timing and counting, and issuing signals to the
various systems. The various sensors and control devices are indicated generally
in the block diagram of Figure 7 (and also in Figure 4) and will be seen to comprise
a variable speed controller 82 for controlling the speed of motor 50 driving pump
48, and pressure transducer 54. Transducer 56 senses the pressure of the suspension
in conduit 54 as delivered by the pump 48, and supplies pressure signals back
to the controller 80 which will in turn send control signals to the speed controller
82 and motor 50.
Opening of valves 32 will cause a pressure drop in conduit 54. Motor
50 will then speed up to maintain the desired injection pressure.
Closing of valves 32 will cause a pressure rise. Motor 50 will then
slow down to avoid an overpressure in conduit 54.
Control of the operation of the main cylinder 27 is achieved through
a main cylinder control board 86 connected to receive control signals from the
controller 80. The control board 86 is in turn connected to a main cylinder solenoid
control valve 88, controlling the main cylinder 27 in a manner known per se.
The main cylinder 27 is, in turn, connected (through the frame 27)
to the encoder 60 (Figure 4) and the encoder 60 is in turn connected so as to deliver
signals to the central controller 80.
In order to control the movement of the conveyor belt 42, the hydraulic
motor 44 (Figure 4) is controlled by means of a belt advance solenoid valve 90,
which is in turn connected to receive control signals from the controller 80.
Motor 44 is connected to belt advance encoder 58 (Figure 4) which is in turn connected
to deliver signals to the controller 80.
In order to control the stripper plate cylinders 40, a stripper plate
solenoid valve 92 is provided, connected to receive signals from the controller
80, and thus control the stripper plate cylinders.
Any suitable source of hydraulic power such as the pump 94 and motor
96 are provided, for supplying hydraulic power for the main cylinder 27, the stripper
plate cylinders 40 and the hydraulic motor 44, in a manner known per se.
The operation of the apparatus is self evident from the foregoing
description. Meat muscle sections are simply placed on the conveyor belt 42, which
will then advance them step wise, so that they will stop and register with the
needles. The cylinders 40 and 28 are then operated to operate the stripper plate
and the header 29, and the needles will plunge downwardly and upwardly. The pump
48 will operate to force suspension through the needles into the meat sections.
As the needles move upwardly and the stripper plate releases the meat sections,
the belt will then advance the meat sections a predetermined increment, at which
point the belt will stop and the meat sections are again injected, and so on until
the appropriate volume of suspension has been injected.
If one or more needles do not pierce a meat section, either because
they do not register with one, or because of a piece of bone, then suspension will
nevertheless be ejected by those needles, since all valves for all needles open
This has the effect of flushing all needles in each injection cycle
and prevents gelling of suspension in some needles. Ejected suspension is recovered
and recycled as described.
Throughout the operation, the controller 80 monitors all factors
in the operation including the position of the needles, the pressure of the suspension,
the movement and position of the belt, and the movement of the needles and the
stripper plate in such a way as to optimize the operation of the apparatus.
It will thus be seen that the method in accordance with the invention
comprises the steps of moving meat sections along a predetermined processing part
in a stepwise start stop fashion, moving a predetermined plurality of injection
needles in a direction generally transverse to said meat sections, while stopped,
whereby at least some of said needles will penetrate said meat sections, operating
injection pumping means to pump a suspension of meat particles as described herein
through all of said needles simultaneously, whether the same have penetrated meat
sections or not, withdrawing said needles from said meat sections, collecting
any excess suspension which has escaped from said meat sections, or which has been
discharged by needles which have not penetrated meat sections, passing said collected
suspension to collecting tank means, recycling same to said injection pump means,
for reinjection through said needles.
After processing, when meat products treated in this way are cut
for serving, it is found that the meat presents a smooth homogenous and aesthetically
pleasing texture, without the appearance of marks or blemishes caused by the injection
process, which were customary in the past.
The foregoing is a description of a preferred embodiment of the invention
which is given here by way of example only. The invention is not to be taken as
limited to any of the specific features as described, but comprehends all such
variations thereof as come within the scope of the appended claims.