Method for tenderizing cut meat portions

There is provided a method for tenderizing cut portions of meat, wherein the portions are slit by passing the portions into a plurality of rotating slitting blades having a plurality of discrete cutting surfaces on each slitting blade along the periphery thereof. A series of closely spaced first cut slits are produced from at least one surface into the said portions. The portions are then sprayed with a tenderizer solution containing a tenderizing phosphate, and the solution penetrates into and is retained in the said first slits. Further slitting of the portions is achieved by passing the portions into a further assembly of the rotating slitting blades and a series of closely spaced further cut slits are placed on the portions. The further slits are close to or in part overlap the first slits and the solution penetrates from or flows from the first slits into the said further slits during the further slitting and subsequent thereto. Immediately thereafter the portions are packaged and fast frozen. The total volume of the first slits is sufficient to retain from 5% to 16% of the solution, and the number of first and further slits is sufficient that solution so penetrates or flows into the further slits from the first slits prior to the freezing step such that the solution is essentially uniformly dispersed in the portions and the portions are essentially uniformly tenderized.

The present invention concerns a method for tenderizing cut portions of 
meat, and more particularly to a method wherein a tenderizing solution, 
containing a phosphate tenderizer, is uniformly dispersed in the meat 
portions by means of rotary slitting blades and subsequent infusion. 
BACKGROUND OF THE INVENTION 
The consumer acceptance of meat, e.g. beef, pork and polutry, depends, to a 
large measure, on the tenderness of the meat after cooking. When the meat 
is tough and fibrous, consumer acceptance is quite low. Meat prepared for 
home consumption and sold in local groceries and butcheries is normally of 
the more tender grades, e.g. choice or prime in the case of beef. To 
obtain those more tender grades, the animals or fowl must be carefully 
selected and in the case of beef, lot feeding of the beef is required in 
order to develop in the muscle tissue the desired amount of tenderness, 
including increases fat content, referred to a marbling. However, such lot 
feeding considerably increases the cost of the meat, and for this reason 
considerable effort has been expended in the art to provide methods for 
tenderizing less tender grades of meat, e.g. cutter, canner, utility or 
commercial grades in the case of beef. In addition, the more tender 
grades, e.g. choice grade in the case of beef, sometimes still do not have 
the degree of tenderness desired and the art has sought methods for 
improving the tenderness of these more tender grades. 
Generally speaking, the efforts in the art for improving the tenderness of 
meat have taken three different approaches, i.e. aging, mechanical and 
chemical tenderization, although these approaches are not mutually 
exclusive. Aging the slaughtered meat is a traditional approach, but this 
requires cold storage of the meat for substantial lengths of time and 
considerably increases the cost of the meat. In addition, aging 
necessarily entails some loss of meat due to the aging process. 
Mechanical tenderization of the meat is achieved by passing the meat 
through mechanical tenderizers. However, such mechanical tenderizers may 
substantially change the texture and appearance of the meat and, 
accordingly, render the meat less desirable, except in regard to certain 
cooking applications. Typical of such mechanical tenderization is the 
conventional "cubed" steak. More severe mechanical tenderization results 
in "ground" meat, and this extreme mechanical tenderization severely 
limits the mode of cooking the meat. Thus, neither aging nor mechanical 
tenderization is fully satisfactory. 
One approach of chemical tenderization is that of enzyme tenderization. In 
this method, enzyme solutions are placed in and on the meat, and during 
storage of the meat at above freezing temperatures, the enzymatic action 
causes degradation of protein and a tenderization of the meat. However, 
with enzyme tenderization it is critical that the enzyme solution be 
relatively uniformly dispersed on and in the meat, since non-uniform 
dispersement will result in non-uniform tenderization and can result in 
over tenderization. Thus, if a large amount of the enzyme solution is 
localized in the meat, that portion will become exceedingly tender that 
even of a "mushy" consistency, while in other areas of the meat where the 
amount of enzyme solution is much lower, the meat may remain relatively 
tough. Thus, enzyme tenderization not only requires some aging time, but 
is difficult to control from the uniform tenderness point of view. 
Another method of chemical tenderization is that of tenderization with 
phosphate solutions. These solutions will more quickly cause tenderization 
of the meat and long dwell times are not required, e.g. times of 4 to 8 
days have been suggested (see U.S. Pat. No. 3,207,608). However, similar 
to enzyme solutions, the uniformity of tenderization depends upon the 
uniformity of dispersing the phosphate solutions in the meat, although the 
action thereof does not cause the excessive over tenderization, as do 
enzymes. However, the phosphate tenderization requires substantial amounts 
of water to be associated therewith, as opposed to the amount of water 
normally used in enzyme solutions. Typically, the amount of enzyme 
solution placed in the meat is only about 3%, whereas the amount of 
phosphate solution placed in the meat is ideally about 10%, i.e. the use 
of phosphates requires about three times as much solution to be placed in 
the meat. As a result, it has been difficult for the art to place that 
higher amount of tenderizer solution in the meat and, hence, achieve 
adequate tenderization with phosphate solutions. 
In this latter regard, cut portions of meat have been allowed to dwell in 
phosphate solutions for considerable lengths of time. However, this 
process is exceedingly slow and not economical from a commercial point of 
view. In addition, it is difficult for the phosphates to permeate the 
entire cut portion of meat and unequal tenderization results. 
More recently, the art has porposed combinations of mechanical and chemical 
tenderization, i.e. with enzymes and phosphates. For example, in U.S. Pat. 
No. 3,971,854, it is proposed that meat (in this case "choice" subprimal 
cuts) be mechanically tenderized by passing the meat through a multiple 
blade (or pin) type tenderizer where reciprocating blades completely 
penetrate the meat to tenderize it. Thereafter, an aqueous solution of 
phosphate is pumped into the meat by way of stainless steel needles and 
high pressure. However, pumping of phosphate solutions into the meat, 
either with or without mechanical tenderization is not entirely 
satisfactory, since a uniform dispersement of the phosphate solution in 
the meat is not achieved by way of a practical number of needles piercing 
the meat. Some success has been experienced by pumping the phosphate 
solution through the arterial network of whole hams, but this process is 
not applicable to cut serving portions of meat. In addition, trimmings 
from the subprimal cuts, when cutting into serving portions, cannot be 
used to produce pure beef or unflavored beef products. About 15%-35% of 
the usual subprimal cut is trimmings when cutting serving size steaks. 
Canadian Pat. No. 792,201 suggests treating meat with either a liquid or 
dry phosphate composition, wrapping the treated meat in plastic film and 
allowing the meat to age for a period time. While this will provide an 
opportunity for the phosphates to penetrate the meat and effect some 
tenderization, the time period required for meaningful penetration of the 
phosphate is too long for commercial operation. Also see U.S. Pat. No. 
3,625,708. 
In U.S. Pat. No. 3,149,554 there is disclosed a tenderizer which has a pair 
of knife rolls which are mounted on axles for rotation and which are 
adapted to receive thereinbetween conveyed meat cuts. Each axle has a 
plurality of cuber knives with discrete relatively flat-faced cutting 
surfaces for placing cubing cuts in the meat passing between the rotating 
knives. Tenderizer solution is flooded on the meat as it passes between 
the knives to impregnate the meat with tenderizer solution. However, it 
was found that the foregoing arrangement, in practice, is difficult to 
control in terms of the amount of tenderizer impregnated into the meat 
cuts. In addition, the cuber knives were found to unduly destroy the 
integrity of the meat cuts, even with minimal use thereof, such that the 
tenderized meat had a texture and appearance similar to "cubed" steak, as 
opposed to the desired texture and appearance of a fresh steak. 
U.S. Pat. No. 3,719,504 suggests that the foregoing difficulties may be 
avoided by the use of the combination of spray nozzles for spraying the 
tenderizer solution and the use of a plurality of elongated, pointed pins 
for perforating the meat, as opposed to the "cuber" knives. In this 
process the plurality of pins penetrate the meat from one side and 
immediately thereafter the apertured meat is sprayed with a tenderizing 
solution (unidentified) so that the solution can be received in the 
apertures prior to the apertures being closed by natural relaxation of the 
tissue around the apertures. However, in this case, the pins (of a 
Bettcher reciprocating tenderizer type) are quite narrow and the resulting 
apertures pick-up only about 3% of tenderizing solution, i.e. suitable 
only for enzyme solutions. Additionally, even that process causes 
difficulties, in that the apertures formed by the pins, while effective in 
receiving and retaining tenderizing solution, create considerable 
concentrations of tenderizing solution in the perforated areas and result 
in what is referred to in the art as "hot spots", i.e. spots where the 
meat becomes mushy and unpalatable. 
To avoid the foregoing further developed problem, it has been further 
proposed in that process that, subsequent to penetrating the meat with the 
reciprocating pins and spraying, the meat be further cut with the 
rotataing cubing knives but only to the extent to further distribute the 
tenderizing solution and avoid the "hot spots". While this arrangement 
works reasonably well for tenderizing solutions which are to be contained 
in the meat in an amount of only about 3% or so, i.e. enzyme tenderizing 
solutions, difficulties have been experienced in containing greater 
amounts of tenderizing solutions in the meat, i.e. tenderizing solutions 
which depend upon phosphates for tenderization. Thus, when sufficient 
penetrations of pins are used to accommodate the higher amounts of 
tenderizing solutions, i.e. above about 5% or more, the many pin 
penetrations tend to undesirably mechanically disintegrate the meat, and 
produce an unpalatable soft texture, tending to be in the nature of 
"cubed" steak. 
As can therefore be appreciated, the art has experienced considerable 
difficulty in reaching a satisfactory balance between mechanical 
disruption of the meat fiber for infusing the meat with tenderizing 
solution, and producing a texture of the tenderized meat which is 
acceptable to the consuming public. This has been a particular problem 
with less tender grades of meat, i.e. canner, utility, commercial and 
cutter grades. It would therefore be of considerable advantage to the art 
to provide a method for tenderizing meats while at the same time retaining 
a desirable texture of the tenderized meat. It would further be of 
advantage to the art to provide such processes wherein the tenderization 
may take place as an essentially continuous process, all the way through 
freezing, and where no lag period is required for action of a tenderizing 
solution. 
OBJECTS OF THE INVENTION 
It is therefore an object of the invention to provide a method for 
tenderizing cut portions of meat with both mechanical tenderization and 
tenderizer solution, but wherein the process may be practiced as a 
continuous process and with no tenderizing lag period required. It is a 
further object of the invention to provide such a process wherein the 
tenderized meat retains a desired and palatable texture. It is a further 
object of the invention wherein the process may be practiced, with 
accpetable results, when canner grade and like less tender meat portions 
are used in the process. Other objects will be apparent from the following 
description and claims. 
BRIEF DESCRIPTION OF THE INVENTION 
Broadly stated, the invention resides in a critical combination of 
mechanical and chemical tenderization, wherein the specific mechanical 
tenderization method enhances the chemical tenderization and vice-versa. 
The critical combination is that of slitting, rather than perforating or 
"cubing", cut portions of meat, and using a phosphate tenderizer, rather 
than an enzyme or other chemical tenderizer, and then again similarly 
slitting the cut portion to uniformly distribute the phosphate tenderizer 
solution. The process will not work with other than phosphate tenderizers 
and the phosphate tenderizers will not work with other than this dual 
slitting of the cut meat portions. 
In more detail, the invention is based on three primary discoveries. First 
of all, it was discovered that in order to contain in the cut portions 
greater amounts of phosphate tenderizing solution, while at the same time 
not so mechanically disrupting the meat as to produce unpalatable results, 
a special slitting of the meat for retaining the tenderizing solution is 
required. As opposed to perforations or cubing cuts, practiced in the 
prior art, the present process produces relatively large "slits" in the 
meat, which are far more capable of readily receiving and retaining larger 
amounts of tenderizing solution, while not producing an unpalatable 
result. While not entirely clear, it appears that the greater surface 
opening of the slits, as opposed to perforations and cubing cuts will far 
more quickly receive and retain larger volumes of tenderizing solution, 
with less mechanical degradation of the texture of the meat. While not 
bound by theory, it appears that the wetting action of phosphate 
tenderizing solutions is more adaptable to be flowed into, received by, 
and retained by slits than by shaft-like perforations or cubing cuts. 
Secondly, it was discovered that since slits far less mechanically degraded 
the texture of the meat, as opposed to the prior practices, considerably 
more slits could be placed on the surface of meat while yet retaining the 
desired meat texture. This is particularly true when all of the slits, 
which run in the same direction on the meat, are not continuous, but 
discrete, and do not greatly overlap each other. Thus, the integrity of 
the meat is retained, even though the surface of the meat is considerably 
opened for receiving phosphate tenderizing solution. 
Lastly, it was discovered that even though the required higher volumes of 
phosphate tenderizing solution could be retained in the meat by using such 
slits, desired distribution of the phosphate solution was not achieved 
thereby. To further distribute the phosphate solution retained in the 
slits, it was found that further slits must be placed in the meat in close 
juxtaposition to the first slits retaining the phosphate solution. While 
some of these further slits may overlap the first slits retaining the 
phosphate solution, the majority of the slits will not overlap and the 
integrity and texture of the meat will be retained. The further slits 
provide pathways for flow and penetration of the phosphate solution from 
the first slits into the further slits. The mechanical movement of the 
meat during the further slitting accelerates this process and at the 
termination of the further slitting, the phosphate solution is relatively 
uniformly distributed in the meat. 
With such relatively uniform distribution of the phosphate solution in the 
meat, tenderization of the meat will be exceedingly rapid, without "hot 
spots", while at the same time the desirable texture of the meat is 
retained. With such rapid tenderization, the meat may be processed as a 
continuous process, all the way through the freezing step, and no 
tenderization lag or dwell period is required. 
This slitting-type mechanical tenderization and redistribution method, 
which provides a large number of openings for tenderizer solution, is also 
useful with enzyme tenderizing solutions. However, in this case there is 
no need for the second slitting step, although the second slitting step is 
innocuous when used with enzyme tenderizer solutions. The first slitting 
step and second redistribution slitting step of the present invention have 
their major advantages in use with phosphate tenderizer solutions. 
Slits required by the present process may be easily placed in the meat with 
rotating blades having discrete, acute angle cutting surfaces along the 
periphery thereof. Acute angle in this regard, means that the cutting 
surface is generally disposed within an acute angle to a diameter of the 
blade, as explained more fully hereinafter. 
Thus, the invention provides a method for tenderizing cut portions of meat 
having upper and lower generally planar and parallel portion surfaces. The 
process comprises slitting the portions by passing the portions into a 
plurality of rotating slitting blades having a plurality of discrete 
cutting surfaces on each blade along the periphery thereof. A series of 
closely spaced first cut slits thereby extend from at least one surface 
into the portions. The at least one slitted surface is sprayed, either 
simultaneously with and/or immediately subsequent to the first slitting 
step, with a tenderizing solution containing a tenderizing phosphate. The 
solution penetrates into and is retained in the first slits. The portions 
are then further slit, immediately subsequent to the spraying step, by 
passing the portions into a plurality of rotating slitting blades having a 
plurality of discrete cutting surfaces on each blade along the periphery 
thereof. A series of closely spaced further cut slits extend from that at 
least one surface into the portions. The further slits are close to or in 
part overlap the first cut slits and the solution penetrates from or flows 
from the first slits into the further slits during the further slitting 
and subsequent thereto. The portions containing the tenderizing solution 
are then immediately packaged and fast frozen. 
The total volume of the first slits is sufficient to retain therein from 
5%-16% of the tenderizing solution and the number of first and further 
slits is sufficient that the solution so penetrates or flows into the 
further slits from the first slits prior to the freezing step such that 
the solution is essentially uniformly dispersed in the portions and the 
portions are essentially uniformly tenderized.

DETAILED DESCRIPTION OF THE INVENTION 
As briefly noted in FIG. 1, the basic steps of the process are that of 
feeding pre-sized, shaped and cut meat portions of the meat into a first 
slitting step where the presently required slits are placed in the meat. 
Immediately thereafter, a phosphate tenderizing solution is sprayed on the 
meat. Since the slits remain open, at least for a short time, a simple 
spraying of the tenderizing solution is effective in placing the 
tenderizing solution in the slits, particularly since the slits receive 
and retain the solution to a substantially greater extent than 
perforations. Thereafter, a further slitting step is performed to place 
further slits in close juxtaposition to the first slits containing the 
tenderizing solution. This further slitting step causes the tenderizing 
solution to flow from the first slits into the further slits. Penetration 
from first to further slits is also involved in this redistribution of 
tenderizing solution, as well as the mechanical action of the further 
slitting. Thereafter, the tenderized meat may be packaged and frozen 
without a tenderizing lag or dwell period. 
FIG. 2 shows, in diagrammatic form, rotatable slitting blades suitable for 
placing the presently required slits in the meat. Thus a pre-shaped, cut 
portion 1 of meat is passed into a plurality of rotating slitting blades 2 
(with upper blades 2a and lower blades 2b). The blades may cut from only 
one surface of the meat, i.e. the upper surface 3 by using only blades 2a 
or blades 2a and 2b may be disposed above and below the meat (as shown in 
the drawings) so that both the upper surface 3 and the lower surface 4 
will be simultaneously cut. If only the upper surface 3 is cut, and the 
meat portions are processed according to the present invention, it will be 
necessary to invert the so processed portions so that the previous lower 
surface 4 becomes the upper surface 3 and the portions are again processed 
in the manner described above. However, for economical reasons, it is 
preferred that both the upper and lower surfaces of the portions be 
processed at the same time. Thus, an upper blade 2a and a lower blade 2b 
will be used. 
In practice, for economical reasons, there will be a plurality of upper and 
lower blades 2 extending transversely along the direction of the travel 5 
of the meat, so as the meat passes therethrough a series of slits will be 
placed in the meat in the direction of travel of the meat. 
Each slitting blade will have a number of discrete cutting surfaces 6 on 
the periphery thereof (also see FIG. 4). The number of cutting surfaces 
and the size thereof can be chosen such that the number and size of slits 
desired will be produced by the blades as the meat is cut by the blades. 
The blade thickness will generally be from about 0.02 to 0.05 inch thick 
to produce a corresponding width of slit. The blades are carried on a roll 
or axle 7 and 8, each axle carrying a plurality of axially disposed 
slitting blades 2, with the periphery of the blades on any one axle being 
spaced apart from the periphery of the blades on any other cooperating 
axle, e.g. the lower axle 7 and upper axle 8. The blades are also spaced 
apart from an adjacent blade by spacers 16 (see FIG. 4) which are, for 
example, from 1/64 to 1/2 inch wide, e.g. 1/8 inch wide. The path of 
rotation of the blades on an upper axle may also be laterally offset from 
the path of rotation of the blades on a cooperating lower axle. This is to 
insure that the blades 2a do not come into contact with blades 2b (e.g. a 
minimum clearance of 0.005 inch and usually a clearance of from 0.01 to 
0.03 inch) and that the meat portions 1 may thereby be passed between 
counter-rotating blades 2a and 2b with the slits cut by both blades into 
both upper surface 3 and lower surface 4 of the meat without blade to 
blade engagement. 
Since cut portions 1 will vary in thickness, at least to some extent, the 
axle carrying at least one set of the blades should be resiliently mounted 
so that it may move up and down in relation to different thicknesses of 
meat. This will provide a relatively constant slit depth in portions of 
varying thicknesses. Preferably, the resilient mounting is by way of an 
air cylinder (not shown) so that a constant pressure is placed on the 
resilient axle, irrespective of the precise thickness of meat passing 
through the counter-rotating blades. In addition, the resilient mounting 
of the blades will avoid damage to the blade rolls when, inadvertently, 
insufficiently tempered meat or meat containing bone is passed through the 
blade rolls. 
While not necessary, the rotating slitting blades may have guide members 10 
and 11 to guide and support the meat portions 1 as they pass between the 
rotating blades 2. In addition, a conveying means 13 for conveying the 
meat to the rotating blades and a conveying means 14 for removing the cut 
meat from the blades will be provided. 
The cutting surface 6 of the blades will be so configured that the slit 
made in the meat by each cutting surface will be less than 1 inch in 
length, i.e. the length of the sharpened cutting surface 6, at the desired 
depth of penetration, will, during rotation in the meat, produce a 1 inch 
slit. More preferably, the cutting surface 6 will be configured to produce 
slits of less than 1/2 inch in length but greater than 1/4 inch. To 
achieve slitting of this nature, acute angle cutting surface 6 is 
generally disposed within an acute angle .theta., formed between a 
diameter of the blade 17 and the general centerline 18 of the cutting 
surface 6 (see FIG. 2). The angle .theta. will generally be between 
45.degree. and 20.degree.. 
Also, the number of blades arranged on any axle will be such that the slits 
placed on the meat are relatively close together, in the direction 
transverse to the direction 5 of the travel of the meat. Ideally, the 
slits are within 1/2 inch of the next adjacent slit in the direction 
transverse to the travel of the portions. 
Additionally, the cutting surfaces 6 should be configured such that the 
first slits extend into the slit portion to less than about 1/2 of the 
thickness thereof. The further slits may extend into the cut portion about 
the same amount, but since these further slits are primarily for 
redistributing the phosphate solution in the first slits, the degree into 
which these slits extend in the cut portions need not be as great. Thus, 
the further slits may extend into the portions to less than about 1/3 of 
the thickness thereof. 
As noted above, it is important that the slits be placed in the cut 
portions in a number and of a volume sufficient to retain the higher 
amounts of phosphate solution required for tenderization. However, also as 
noted above, the number and extent of slits should not be so great as to 
substantially destroy the integrity of the cut portions. If the integrity 
of the cut portions is destroyed, then upon cooking, the cut portions will 
tend to disfigure and will not have the appearance of a unprocessed 
beefsteak, or the like. While the ultimate number of slits which can be 
placed in the meat will vary with the particular kind of meat, generally 
speaking, the further slits should not be closer to the first slits than 
approximately 1/16 of an inch, and more usually about 1/8 inch or so. When 
slits have the depth, in the range described above, as well as lengths, as 
described above, this close spacing of the slits will still not 
substantially degradate the integrity of the cut portions. 
It is not necessary that all of the slits be produced with one axle 
carrying a plurality of blades or even a set of two axles carrying a 
plurality of blades. The slits may be achieved by a plurality of sets 
(upper and lower axles carrying a plurality of blades), as shown in FIG. 
3. Thus, the slitting blades 2 in both the first and further slitting 
steps may comprise two counter-rotating axles 20 and 21 carrying a 
plurality of axially disposed blades with cutting surfaces 6, and with the 
periphery 22 of the blades on one axle being spaced apart from the 
periphery 22 of the blades on the other axle. Thus, as the portions are 
passed between the counter-rotating blades the slits are cut therein. Two 
sets of those axles and blades may be used for each of the first and 
further slitting steps, as shown in FIG. 3, i.e. the first slitting step 
has two sets of two axles/blades (20, 21, 23 and 24) and the further 
cutting step has two sets of two axles/blades (25, 26, 27 and 28). Indeed, 
any number of blades may be used, as desired, to place the slits in the 
meat portions, so long as the slits ultimately produced in the cut 
portions are in the nature as described above. 
Also as shown in FIG. 3, after the first cutting step, the tenderizing 
solution is placed on the meat (while held on the conveyor) by spraying 
devices 29 and 30. The further slitting step is then achieved, as noted 
above, and the slit portions with the tenderizing soltuion therein 31 are 
conveyed to a packaging machine 32 for packaging, i.e. individually 
packaging or packaging as a group and then conveyed to a freezer room 33 
for fast freezing. This may be a continuous process and after the further 
slitting step, normally speaking, the packaging and fast freezing of the 
so processed portions will immediately take place. This does not mean, 
however, that there cannot be some lag or dwell period after the further 
slitting, but it does mean that such lag or dwell period is not required. 
Thus, normally speaking, after the further slitting step, the lapsed time 
between that further slitting step and introducing the portions to the 
fast freezing step will not be greater than about one hour, allowing for 
normal production and handling, and usually only about a quarter hour or 
less. Indeed, normally speaking, the time between spraying the meat 
portions with the first slits and packaging and fast freezing the portions 
will normally be no greater than two hours and usually no greater than one 
hour. Indeed, this entire process will normally be accomplished in a time 
period no greater than one-half hour. 
The slitting time will be relatively short, but this time will depend upon 
the length of the slit and the depth of the slit desired, as well as the 
number of desired slits. In addition, slitting will be more difficult or 
easier depending upon the nature of the meat being cut and its 
temperature. Partially frozen meat, of course, will be more difficult to 
cut and for this reason it is preferred that the cut portions passing 
through the process, up to the freezing step, be at a pliable temperature, 
i.e. a temperature in which the meat is not rigid. When the meat portions 
are preformed beefsteak portions, pliable temperatures begin at about 
26.degree. F. The lower the temperature the better, and thus, it is 
preferred that the temperature of the beef portions be between about 
27.degree. and 29.degree. F. 
The tenderizing phosphate solution may contain any of the known tenderizing 
phosphates. These tenderizing phosphates are generally alkali metal or 
alkaline earth metal phosphates. However, for practical use, it is 
preferred that the phosphate is either sodium tripolyphosphate or sodium 
hexametaphosphate, or sodium acid pyrophosphate, or tetra sodium 
pyrophosphate or combinations thereof. The concentration of the phosphate 
in the solution will normally be between about 3 and 10% and this will 
achieve a phosphate pick-up in the meat (on a dry basis) of about 0.5%. 
However, phosphate pick-up of between about 0.3 and 1% is normally 
satisfactory. This pickup is, of course, dependent upon the amount of 
phosphate solution, as well as the concentration of phosphate therein. As 
noted above, substantial amounts of water must be associated with the 
phosphate, and the meat should pick-up from about 5% to 16% phosphate 
solution. Generally speaking, however, the amount of solution retained in 
the so processed portions will be approximately 10%, i.e. weight of 
steak+solution-weight of steak.div.weight of steak and .times.100. 
The phosphate solution may contain other non-essential ingredients, such as 
bactericides (the sprayed phosphate solution may be recirculated as it 
drips from the sprayed meat), fungicides or other preservatives, wetting 
agents (e.g. a Tween), antioxidants, viscosity control agents, e.g. gums 
and the like, or even other tenderizing ingredients such as wherein the 
solution also contains a tenderizing enzyme or mixture of enzymes, e.g. 
ficin and bromelain in concentrations of 0.1% to 2%. 
The product of the present invention has more natural beef flavor than 
enzyme tenderized meat and far superior texture, since there has been no 
protein degradation by the enzyme. The tenderness is at least as good as 
enzyme tenderized meat; the color is brighter; the color does not darken 
as quickly after thawing; the meat will "purge" (weep) considerably less; 
does not visually shrink and can be safely thawed for 5 days versus 2 days 
for enzyme tenderized meat. No over tenderization is experienced and the 
meat is more juicy than enzyme tenderized meat. 
It has also been suprisingly found that slits of the present nature have a 
tendency to seal shortly after being cut. Thus, these narrow, but deep 
slits can receive the phosphate tenderizing solution immediately after 
cutting and then re-close or seal prior to packaging and freezing. This 
allows a larger amount of solution to be retained by and permeate into the 
meat even with the handling necessary for packaging and freezing. Further 
it has been surprisingly found that even when thawed, the partially sealed 
slits will be virtually invisible and upon cooking, e.g. broiling, the 
slits will essentially totally seal. This prevents natural juices and the 
additional moisture added by way of the solution from cooking out of the 
meat and provides the juicy mouth feel of unprocessed tender grades of 
meat, e.g. choice grade. 
It has also been surprisingly found that meat processed according to the 
present invention can be cooked in the restaurant immediately after 
thawing. In fact, when necessary, steaks can be fast thawed or brought to 
a tempered state (approximately 26.degree. F.-30.degree. F.) and 
immediately cooked without loss of tenderness. This, for example, can be 
done in a microwave oven. Frozen enzyme treated steaks are normally held 
after thawing at refrigerator temperatures for 8 to 16 hours in order to 
permit adequate dispersement of the enzymes solution and to insure a 
uniformly tenderized steak. The present improvement is important in the 
operation of restaurants, in that frozen steaks can be more quickly 
readied for cooking, resulting in better inventory control and lower 
inventories. 
The invention will now be illustrated by the following examples, but it is 
to be understood that the invention is not limited to these examples, but 
extends to the scope of the foregoing disclosure and the following claims. 
In the examples, as well as in the foregoing specification and following 
claims, all percentages and parts are by weight, unless otherwise 
specified. 
EXAMPLE 1 
Boneless beef striploins were inspected, and fat and tail trimmed, as 
needed. The striploins were frozen in a blast freezer, and then tempered 
in a tempering room held at an air temperature between 
28.degree.-30.degree. F., with brisk air movement. When the striploins 
were equilibrated to temperatures between 27.degree.-29.degree. F., they 
were molded in a Bettcher* molding press and then sliced with a Bettcher* 
slicer to a predetermined desired steak weight. 
FNT *Trademark 
The steaks were inspected and offcuts and wedge-cuts culled out. The 
selected steaks were conveyed by a conventional wire belt conveyor into a 
double set of rotary slitting blades of the configuration shown in FIGS. 3 
and 4. Immediately after cutting, the steaks were continuously conveyed 
through a spraying machine for applying the tenderizing solution 
(described in detail below). The amount of spray applied produced a 
pick-up of from 8-10%. The desired pick-up is adjustable by changing the 
speed of the spray tunnel conveyor, or throttling or opening wider the 
valve feeding the sprays from the pump. The spray nozzles were wide 
deflector-type and produced a flat spray pattern with low impact 
characteristic (manufactured by Spray Systems Company No. 1/8 K1 to No. 
1/8 K20 with 0.033 inch to 0.148 inch orifice diameters), with liquid 
pressure between 10 psi and 60 psi. A closed sanitary dairy pressure 
filter is provided to filter out the fine fat and meat particles from 
recirculated solution. 
From the spray tunnel the steaks were conveyed to further double set of 
rotary slitting blades where the solution is further redistributed 
throughout the steak and any free liquid remaining on the surface of the 
steak is forced into the steak interior. From the further double set of 
rotary slitting blades the steaks were packaged in plastic film (bags), 
and boxed. The boxed steaks were blast frozen. 
The rotary blades (first and further sets) were mounted on an axle with 
spacers thereinbetween. The spacers were 0.139 inch wide so that spaces 
between blades were approximately 1/8 inch. This arrangement will handle 
boneless steaks of up to 3 inches thick, although the steaks used in this 
example were approximately 1 inch to 11/2 inches thick. The thickness of 
the blades are from 0.030 inch to 0.040 inch in thickness. The blades of 
the upper axle were laterally offset from the blades of the lower axle and 
the peripheries of the upper and lower blades had a clearance of about 
0.01 inch. The individual blades (as shown specifically in FIG. 4) were 
shaped so that the blade enters the steak close to the point of the 
cutting surface, and the cutting surface penetrates the steak and 
membranes and withdraws from the steak in a smooth motion. This smooth 
cutting action is enhanced by the ground sharp side of the cutting surface 
which also prevents breakage at seams in the steaks, particularly rib eye 
steaks and sirloin butts. This is opposed to the pounding action of 
reciprocating knife blades and pins, such as the Bettcher* bladed 
tenderizer, which tend to break the steak at the membranes seams. 
FNT *Trademark 
Because of the semi-rigidity (pliable) condition of the steaks, there is a 
slight displacement of the steaks, so they are slightly wider and longer 
after passing through the process. 
Thereafter, some of the frozen steaks were thawed. After thawing the steaks 
relaxed, due to numerous slits, and upon cooking provided greater plate 
coverage than conventionally prepared steaks. The absorption of the 
solution slightly swelled the cooked steaks, which also gave larger 
surface area of the cooked steaks than conventionally prepared steaks. 
The slits in the steaks partially seal themselves during the period after 
passing from the further set of blades and prior to blast freezing. During 
cooking, the steaks complete this sealing process, so that the cooked 
steak is virtually indistinguishable in surface texture from a steak which 
has not been slit. 
The tenderizer solution formulation was as follows: 
Seasoning mix (salt, sugar hydrolyzed vegetable protein, dextrose, 
monosodium glutamate, beef extract and spices)--12.5 lbs. 
Sodium tripolyphosphate--8.75 lbs. 
Water--165. lbs. 
The phosphate was mixed with the water (at lukewarm temperature) until 
dissolved and then the spices are mixed. 
EXAMPLE 2 
The procedure of Example 1 was repeated except that only one set of upper 
and lower slitting blades were used (i.e. 20 and 21 of FIG. 3). Although 
steaks were tenderized to some extent, the steaks required a dwell period 
of at least 2 hours and up to 6 hours in a 35.degree. F. cooler to become 
acceptably tender. 
EXAMPLE 3 
The procedure of Example 1 was repeated except that only the first double 
set of slitting blades were used (i.e. 20, 21, 23, 24 of FIG. 3). With 
this procedure the dwell period of Example 2 could be eliminated, but the 
tenderness of the steaks was only marginally acceptable. 
EXAMPLE 4 
Cooking tests were conducted by broiling steaks on a charbroiler, in the 
manner performed in franchise steak houses. Sample A was constituted by 
untreated control steaks. Sample B was constituted by the steaks processed 
according to Example 2, except that no dwell period was provided. Sample C 
was constituted by steaks processed according to Example 3. Sample D was 
constituted by the steaks processed according to Example 1. Sample E was 
constituted by steaks processed in a conventional manner with a 3% pick-up 
of a conventional enzyme solution (ficin). 
The following 1-5 scale test was used by blind panelists to rate all 
samples: 
______________________________________ 
RATING DESCRIPTION OF TENDERNESS 
______________________________________ 
5 Extremely tough clearly unacceptable 
41/2 Very tough - unacceptable 
4 Moderately tough - marginally acceptable 
31/2 slightly tough - acceptable 
3 Desired tenderness - similar to U.S.D.A. Prime 
21/2 Slightly overtender - acceptable 
2 Moderately overtender - acceptable 
11/2 Overtender - undesirable but acceptable 
1 Extremely overtender - undesirable but marginal- 
ly acceptable 
______________________________________ 
The average results of all panelists were as follows: 
______________________________________ 
COOKED STEAK TREATMENT RATING 
______________________________________ 
Sample A (control-untreated) 
41/4 
Sample B (Example 2) 31/2 
Sample C (Example 3) 31/4 
Sample D (Example 1) 3 
Sample E (enzyme treated) 
31/4 
______________________________________ 
For purposes of this test scale, a steak must have a rating of under 4 to 
be saleable. For most franchised steak houses, the rating should be under 
31/2, preferably as good as 31/4. Of course, the target value of 
tenderness provided by the tenderizing process is that which is similar to 
U.S.D.A. prime, i.e. 3. Over tenderization is to be avoided, since it 
produces a "mushy" or "processed" mouth-feel. 
EXAMPLE 5 
Boneless strips were cut into 8 oz. paired steaks with one steak of each 
pair being treated according to the procedure of Example 1 to pick up 10% 
by weight of phosphate tenderizer. The steaks were frozen and thawed for 
48 hours and cooked on a heavy cast iron electric grill at 350.degree. F. 
for 4 minutes on each side and to the same degree of doneness (medium 
done). The following results were obtained. 
__________________________________________________________________________ 
UNCOOKED WT. 
COOKED WT. 
LOSS OF WT. 
PAIR GRAMS GRAMS GRAMS % SHRINK 
__________________________________________________________________________ 
#1 
Control 
211.4 159.6 51.8 24.5 
#1 
Tenderized 
233.6 190.9 42.7 18.3 
#2 
Control 
195.7 164.5 31.2 15.9 
#2 
Tenderized 
219.8 192.6 27.2 12.4 
#3 
Control 
186.3 135.4 50.9 27.3 
#3 
Tenderized 
200.9 155.0 45.9 22.8 
#4 
Control 
193.3 141.0 52.3 27.0 
#4 
Tenderized 
211.0 171.7 39.3 18.6 
__________________________________________________________________________ 
The foregoing data may also be presented as follows for case of 
comparison. 
PAIR # 1 2 3 4 
__________________________________________________________________________ 
Cooking loss 
Control % 
24.5 15.9 27.3 27.0 
Cooking loss 
Tenderized % 
18.3 12.4 22.8 18.6 
Cooking loss % 
Difference 
6.2 3.5 4.5 8.4 
__________________________________________________________________________ 
Thus, an average gain of 5.6% on cooked weight of presently tenderized 
steaks is achieved over that of untenderized steaks. 
__________________________________________________________________________ 
Thus, the objects of the invention have been met. It will be appreciated 
from the foregoing detailed disclosure, that various modifications will be 
apparent to those skilled in the art and those modifications are intended 
to be embraced by the spirit and scope of the following claims.