NO134094B - - Google Patents

Description

The invention relates to a method for producing a shaped, consolidated meat product, and this method comprises a number of steps, namely a combination of previously known and new steps.

Many cut pieces of meat contain connective tissue

of such a kind or in such a quantity that the meat is tough to eat if the connective tissue is not completely or partially removed before processing. The term "meat", when used herein, means not only the meat of mammals, but also the meat of fish, poultry and shellfish. The present invention can be used with such meat to convert it into a meat product which, by virtue of its improved tenderness, is more acceptable. The invention can also be used for the utilization of meat waste and meat by-products, which due to their appearance will not be easily marketable, even if such meat represents the same nutritional value as first-class meat.

Tender meat products can be prepared by forming a dough from finely divided, raw meat and shaping the dough, e.g. by pressing it into molds, and then heat-solidifying it to consolidate it so that a compact meat product is obtained, which can then be cooked and served in a shape resembling a piece of whole meat. Such a product, which can be called reformed or improved meat, will nevertheless, when consumed, prove to have an irregular structure that is completely different from that attributed to the textures of undivided pieces of meat, which textures are made up of groups of muscle fiber bundles held together by connective tissue, and other associated structures well known to meat histologists. Regulation to a certain extent can be used for textures of such improved meat products by adding to the dough, which is then shaped and consolidated, a proportion of coarsely chopped, cooked meat or an amount of string-like vegetable protein fibres. Improved meat can thereby be regulated to toughness to meet the demands of consumers who expect to have to do a certain amount of chewing

when the product is eaten. This type of product will nevertheless be different in texture and appearance, by virtue of its irregular structure from whole meat that has not been improved, and it will therefore lack the characteristics attributed to good quality whole meat.

We have discovered that it is possible, by a special combination of method steps which include the treatment of specially formed components, to produce an improved meat product which has the physical and organoleptic properties of whole meat of good quality. From divided meat, we have thus become able to obtain a type of improved meat product which very closely resembles tender, undivided meat, and which also provides economic advantages during production in that it is possible to obtain

a higher cooking yield, or in other words a lower liquid loss during cooking, than is possible with improved meat that has not been treated in accordance with the invention.

According to the invention, a method for the production of a shaped, consolidated meat product is provided, comprising the steps of i) making a divided mixture of raw meat, comprising an intimate mixture of raw, lean meat, fat and water, wherein the meat component of the mixture has an average particle size of less than 2 mm, II) dividing cooked meat to provide a texturizing component of discrete muscle fiber bundles, each fiber bundle being from 2 to 50 mm in length and from 0.2 to 2 mm in diameter, III) to mix from 30

to 97.5% by weight of the divided mixture of raw meat and from 2.5 to 70% by weight of the texturizing component to provide a minced meat having, by weight, a total moisture content of

from 50 to 80% and a total fat content of from 1 to 40%.

The method according to the invention is characterized by two steps in addition to the three steps mentioned above, ; namely IV) to extrude the dough through a cylindrical or parallel-sided extrusion die with a length of at least 12 cm and a shortest cross-sectional dimension between opposite sides of less than 3 cm, to form a shaped extrudate where the proportion of muscle fiber bundles that are in substantially parallel alignment with each other, is from 70 to 100%, and V) to consolidate the extrudate by freezing or heat solidification in a manner known per se.

In addition to the meat, the powdered meat product will also contain fat, salt and water, as well as optional additives such as spices, grains, vegetables, flour, vegetable protein materials and other ingredients well known to those skilled in the art.

In the finished improved meat product, it is important that at least 70% of the fiber bundles have a substantially parallel arrangement. When the fiber bundles originate from meat of animals or poultry, it has also been shown that good results are achieved when the fiber bundles are in a cooked state. When it comes to fish or shellfish meat, raw fiber bundles can be used with good results.

The method according to the invention can also be applied to raw fish so that a powdered product is provided which consists of finely divided raw fish in an emulsion of fat and water, stabilized at least in part by raw fish protein, where the raw fish has an average particle size of less than 2 mm, and a texturing component consisting of discrete bundles of muscle fibers, each fiber bundle being from 2 to 50 mm in length and from 0.5 to 2 mm in diameter, mixing the powdered meat mixture and the texturing component with then much fat and water to provide a dough having a total moisture content of from 50 to 80% by weight, and so on as indicated above.

The separated muscle fiber bundles that form part of the dough originate from undivided meat by mechanically separating individual fiber bundles from the groups or surfaces of the fiber bundles that make up the main part of the muscle tissue in meat. Further division of this part into individual fibers or fiber fragments is avoided as far as possible.

It must be understood that in raw meat the muscle fibers are long, narrow, multinucleated cells that can be stretched from one end of the muscle to the other, and they can reach a length of more than 30 cm, although they are usually only 10 to 100^ um in diameter. The length and diameter of muscle fibers vary from one muscle to another, and between species, races and sexes. Muscle fibers in whole muscles or in other words in undivided meat, are grouped in bundles, where each bundle has a membrane of collagen-like protein, known as connective tissue, which consists of irregularly oriented collagen fibers. When meat is cooked, a degree of muscle shrinkage usually takes place with a resulting shortening of the length of the muscle fiber bundles. Cooking also results in at least partial conversion of the connective tissue collagen to gelatin and thus causes partial crumbling of the connective tissue membrane, thus providing a tenderizing effect that is noticeable when cooked meat is consumed.

The muscle fiber bundles referred to here are consequently the fiber bundles that have been separated, by breakdown of the enclosing connective tissue, from the groups of bundles that occur in meat. The size of the separated muscle fiber bundles will depend in part

of the nature and size of the muscle fibres, and partly of the degree of division which is carried out with the meat before or during their separation from each other. It will e.g. it is understood that for meat from mammals or poultry that is slaughtered, the muscle tissue of the animal providing the meat is, for the sake of convenience, cut into pieces, which thus involves dividing and consequently shortening the muscle and its component parts, but it is advantageous to choose the straight fiber muscle meat when muscle fiber bundles of appropriate dimensions are produced.

When the meat is fish or shellfish, the separate muscle fiber bundles are preferably prepared in a raw state for addition to the dough, since we have shown that the use of cooked fish or shellfish can provide separate muscle fiber bundles which are sometimes extremely tough and therefore unsuitable for mixing into the dough . The reason for this occasionally strong toughness is not fully understood, but it is believed to be related to the conditions under which the fish can be stored before use in the method according to the invention.

Apparent toughness can be reduced or avoided by mixing together the separate fish muscle fiber bundles derived from different species of fish, or by mixing together the separate fish muscle fiber bundles with those derived from cooked mammalian or poultry meat.

When the meat is of animal or poultry origin, the separate muscle fiber bundles in the texture-forming component are derived from meat that has already been cooked, and consequently, when incorporated into the dough, in a cooked state, in which the proteins comprising the bundles are completely heat-denatured. In this form, the separated cooked muscle fiber bundles give the final product a desirable textural quality similar to that of tender, unpulverized meat, but it is important to note that the dough into which the separated cooked muscle fiber bundles are incorporated also contains a proportion of a powdered raw meat mixture. This raw meat mixture serves to form a base phase in which the cooked, separated muscle fiber bundles are held in position in the final product, which is then prepared for consumption.

The appropriate method of obtaining separate muscle fiber bundles from slaughtered or filleted meat will depend on the nature and condition of the meat. It is possible to use readily available meat pulverizing equipment, provided that consideration is given to, e.g. by adjusting speed or solidification, that it is certain that the pulverization method is not so vigorous as to break up the meat to such an extent that the separate bundles of muscle fibers thus obtained are of smaller dimensions or are in less quantity than is considered necessary, as defined here.

As an example, separate muscle fiber bundles can be obtained by carefully pressing the selected meat through the pinch on rollers rotating at different speeds, thereby imparting a combing action sufficient to separate the constituent muscle fiber bundles without causing excessive separation. Alternatively, the separated muscle fiber bundles can be achieved by carefully controlled use of other means well known in the industry, e.g. by pulverizing with a silent chopper or a bowl hoe, or by using a colloid mill, a hammer mill or a carborundum disc mill. Such equipment may, if necessary after adjustment or modification, be used to impart a rubbing or combing action to the meat, whether meat of cooked mammals or poultry, or cooked or raw fish, instead of a chopping action which is, to an undesirable degree, sufficient to reduce the average length of the muscle fiber bundles.

When the meat is raw fish or shellfish, we have e.g. found that a convenient way of dividing the meat into one form in which the texturing component contains the required proportion of separate muscle fiber bundles of appropriate size is to force it, if necessary after deboning, through a disc such as has holes that are 1.5 mm in diameter. Other methods of appropriate division of raw fish or shellfish meat may be used.

When the meat is of animal origin, it should be thoroughly cooked after slaughter, for example by boiling in water or by steaming, so that it is converted by heat denaturation into a fully shrunken state before it is broken down into its individual muscle fiber bundles, thereby providing the texture-forming component.

Preferably, the meat is pressure-cooked after slaughter

in an atmosphere of steam. As an example, raw meat can be cut into large pieces weighing around 1 to 2 kg and pressure-cooked at a temperature of 120°C for 60 minutes. The meat can of course be cooked with bones or before separation of other inedible materials that can be removed afterwards, before dividing the meat into muscle fiber bundles.

After cooling and removal of all inedible materials, such as bone and cartilage that may remain, the meat is subjected to the treatment mentioned above, in order to reduce it as far as possible to separate but essentially intact muscle fiber bundles.

When the method according to the invention is applied to meat from mammals or poultry, separation of cooked meat into its constituent muscle fiber bundles can be achieved by subjecting the pieces of cooked meat, preferably after separation of all heavy fat deposits, to a rubbing action in a conventional bowl chopper with a setting of the blade from the bowl wall on. not less than about 2 mm, and preferably about 3 to 4 mm. When a bowl chopper is used to chop raw meat, the rotating blades are usually set at a smaller distance with a clearance of from 0.5 to 2 mm from the bowl wall to achieve a very fine division of the meat. However, we have found that the use of such a fine setting when chopping lean, cooked meat of mammals or poultry results in division to a very fine condition where the proportion of muscle fiber bundles longer than 2 mm is small. However, by using a bowl mincer with a wider blade setting, the cooked meat can be rubbed apart rather than chopped, with the result that the individual muscle fiber bundles in the cooked meat can be easily combed apart and separated from each other without excessive shortening of the length.

The pulverized meat mass which forms part of the dough is then, when heated, intended to act as a binder between the separated muscle fiber bundles and between other structural or special components in the dough that may be present after addition. The finely divided raw meat in the pulverized meat mass should have an average particle size of less than 2 mm.

The nature and size of these added structural or special components will depend on the subsequent treatment to which the dough will be subjected in which it can finally be converted into an edible end product. When e.g. the product is to be dewatered, it is preferred that the finely divided raw meat in the powdered meat mass is supplemented with coarsely ground raw meat,

such as may be obtained by rendering raw meat finer by passing it through a disc having openings not larger than 15 mm, and preferably from 2 to 15 mm, in diameter. This coarsely ground, raw meat thus serves to give the dough an "open" structure that is more susceptible to dewatering. When, on the other hand, the product is intended to be canned or frozen without an intermediate defrosting step, it is not necessary to provide the dough with a coarsely ground raw meat component, since it is preferred to have a more compact structure. But it is not necessary that the original fiber structure of the raw meat, from which it is minced,

raw meat is produced, is completely destroyed, provided that at least 90% by weight of the solids in the finely divided raw meat have the limited particle size that does not exceed about 2 mm.

It is of course possible to include as a proportion of the powdered meat component a heat-coagulable vegetable protein component, e.g. soy protein or peanut protein.

Raw meat can be converted into a very finely divided state, e.g. by pulverizing in a conventional bowl chopper using a conventional regulation of the knife setup, e.g. with a gap of about 0.5 to 1 mm. Other machinery for pulverizing meat, e.g. a colloid mill or a hammer mill, may be used when suitably adjusted for very fine pulverization.

It is particularly important that the pulverization temperature of the raw meat from which the pulverized meat mass is prepared is not high enough to destroy its ability to act as an emulsifier or as a heat-setting binder in any product produced by the process according to the invention. Raw meat may thus be stored frozen or chilled until required for use, and then chopped or cut into large pieces or pieces of a size suitable for the equipment selected for this operation, namely to render meat finer or to pulverize. Further rise in temperature which may occur during coarse grinding or pulverization to a suitably finely divided state can be prevented by the use of refrigeration equipment, or more simply by adding solid carbon dioxide or ice before or during the pulverization step.

When making a meat product from boneless beef, pork or chicken meat, it is preferred that the raw meat can be kept under refrigeration at a temperature of about -18 oC until it is needed for the conversion to the powdered meat mass without appreciable loss of quality. Before the processing it will be

o o o chilled meat cooled at a temperature of from -2 to +1 C for 12 hours. If necessary, large pieces can be conveniently cut up in a semi-frozen state before quenching. Pieces of semi-frozen meat can then be minced with the occasional addition of ice and other ingredients, such as flavorings and salt. In order to achieve the best results, we have found that the temperature of the raw meat during the chopping process should not be allowed to rise above about 15 o C', otherwise the properties and characteristics of the products that are then obtained may be damaged. body affected.

Furthermore, we have found that the production of the pulverized meat mass from raw meat is made easier by using in the selected pulverizing equipment at least part of the water that is possibly to be mixed into the dough. This added water can of course take the form of ice or broth or other liquids, cf. e.g. the liquid that remains after the meat has been cooked. It is also convenient at this stage to mix in additions of fat or oil, which are considered desirable, especially where the raw meat used is lean meat.

The resulting emulsion of water and fat containing finely divided raw meat has a fine texture which on microscopic examination indicates a gel structure with only a few fibers standing out. It is believed that the protein in the finely divided, raw meat acts as a emulsifier for fat and water phases,

and thus provides a stabilized emulsion which then forms the basis of the method according to the invention.

The solids content of the dough should be such that when the dough is extruded, sufficient shear stress is applied to set the separated muscle fiber bundles to the extent defined herein. For this purpose, the non-aqueous solids in the dough should constitute from about 20 to about 50% by weight of the dough, the remainder being water or aqueous phase.

Supplementary water can of course be mixed into the dough when necessary to reduce the content of solids in the dough to a desired value.

The dough should in any case contain at least 1% by weight, suitably from 1 to 40% by weight, preferably from fluff to 30% by weight,

with fat or oil, and some of this may come from the meat from which the muscle fiber bundles have been separated or from the powdered meat mass.

As we have already mentioned, the fat or oil that forms part of the dough should be in the form of an emulsion with water, which is at least partially stabilized by raw meat protein. Other food grade emulsifiers can be used as additives to supplement the emulsifying properties of raw meat protein.

The dough can also include other additives that serve as texture-forming aids, water-binding agents, gel-forming agents, flavorings and colourings. An example of other texturizing aids that can be used are thread-like vegetable protein fibers, especially to supplement the action of the separated muscle fiber bundles. Food grade phosphates, especially polyphosphates, serve as examples of water binding agents that can be mixed into the dough to thereby reduce liquid loss and product shrinkage that can occur when a meat product is cooked. Anti-gel agents, e.g. modified starches and celluloses, e.g. carboxymethyl cellulose, can also be mixed into the dough.

When investigating liquid loss when boiling or heating the subsequently extruded product, we have e.g. observed that the water loss can be as much as 40%, calculated as:

100 x weight of water loss during boiling

weight of dough

But if the dough contains such components as the aforementioned phosphates or suitable starch or cellulose materials, in quantities which have the effect of reducing the amount of water loss during cooking, the above value of up to 40% can drop to 10% or less.

The effect of including a given amount of such a water-binding agent or gelling agent in the meat mixture can be easily investigated by the following simple test: A known weight (suitably about 40 g) of the dough containing the water-binding agent is firmly compressed in the lower half of a cylindrical glass funnel ( diameter 9 cm, length 4 cm). To the base of this is attached a graduated glass which extends downwards (diameter 1.3 cm, length 20 cm) and is closed at its lower end. A perforated plate at the joint prevents the mixture from entering the pipe. The funnel is loosely stoppered, and the apparatus is placed in a batch of water held at 85°C, with only the upper half of the cylindrical funnel protruding from the water, and allowed to stand there for 1 hour. The water and fat that is lost from the mixture during cooking flows into the graduated tube. After 1 hour, the apparatus is removed from the bath, gently drained to facilitate drainage of any additional liquid, and placed back into the bath for 5 minutes. The volume of water in the graduated tube (which water forms a clearly defined layer under the fat) is then read.

The dough, which is then extruded, is conveniently prepared by mixing together suitable ingredients in amounts as defined herein. This mixing process can be illustrated as follows: If one wants to produce a meat product for subsequent canning from a starting material that includes separate, cooked muscle fiber bundles as a texture-forming component,

and finely divided pulverized raw meat as the pulverized meat pulp, the raw meat is first thoroughly mixed with the appropriate amount of fat and water and minor ingredients, such as phosphate, coloring and flavoring, to form an emulsion before being converted into a dough by mixing in separated, cooked muscle fiber bundles. This order of mixing is preferred since it allows to be sure that the separated, cooked muscle fiber bundles are not subjected to excessive processing during mixing which can partially destroy their ability to give the end product an aligned fibrous structure.

Thorough mixing can be achieved using any suitable mixing equipment. But we have found that in order to achieve optimal arrangement of fiber bundles during the subsequent extrusion of the mixture, and in order to obtain a product very similar to cooked, undivided meat during the subsequent cooking, it is necessary to degas the dough. If not, gases trapped in the dough, especially entrained air which is inevitably mixed in during the mixing of the dough, can act on the fiber bundle device, and can, on subsequent extrusion or on subsequent heating, produce a product that can show little resemblance to the undivided or unpulverized meat which it is intended to imitate.

It is not fully understood why trapped air or other gases affect the arrangement of the separated muscle fiber bundles, but it is assumed that the presence of gas absorbed in the dough during extrusion gets in the way of the effect of otherwise uniform shear forces on the separated muscle fiber bundles within the dough, so that the orientation of the fiber bundles in a parallel arrangement is not sufficiently achieved. It is also possible that the disorientation of otherwise ordered fiber bundles in the dough takes place by a sudden release of pressure when the dough being extruded (the extrudate) comes out of a zone of high pressure to the ambient atmospheric pressure. Under these circumstances, it is assumed that dissolved or compressed gas trapped in the dough, while it remains in the extruder,

is released explosively and thus forces at least a portion of the separated muscle fiber bundles out of parallel alignment with respect to each other.

Degassing of the mixture can conveniently be achieved by using a reduction in pressure, e.g. by mixing in a vacuum mixer at least during the final steps. As an example of how this degassing process can be carried out, we have found that a minced meat can be prepared by mixing its ingredients at ambient atmospheric pressure in a Werner and Pfleiderer mixer for 5 minutes, and continuing the mixing for an additional 1 minute after the mixer is been closed gas-tight and the mixing chamber evacuated using a vacuum pump. - In this example, we have found that it makes sense to apply a reduction in pressure to the dough to around 20 cm Hg or lower. It should be understood that other forms of vacuum mixers can be used for the same purpose, e.g. a Hobart vacuum mixer, and that the degree of pressure reduction used is not critical, provided that the trapped gases, which will usually be air, are removed from the dough prior to extrusion. It is also possible to degas the mixture in the equipment used for the extrusion, e.g. by using an earl Schnells sausage stuffer with continuous vacuum.

When the dough has thus been produced, it is extruded through an extrusion die under such conditions that at least 70% of the separate muscle fiber bundles present in the dough are oriented so that they are brought substantially into parallel alignment with respect to each other. It is preferred to extrude the dough to form an extrudate without applying heat during the extrusion step sufficient to cause coagulation of the raw meat protein or of other ingredients of similar properties that may be present in the dough.

The provision of shear forces during extrusion sufficient to orient the separated muscle fiber bundles in the manner described will depend on various factors, such as the viscosity of the dough, the proportion of separated muscle fiber bundles present in the dough, the force applied to extrude the dough and dimensions and design of the extrusion die.

With regard to the critical aspects of the design of nozzles which are suitable for use in accordance with the invention, we have e.g. found that if the dough is extruded via a cylindrical tube 2 cm in diameter and 5 cm long, the degree of rib arrangement in the extrudate is very small, and certainly represents an arrangement of less than 70% of the separated muscle fiber bundles present in the dough. However, if a tube with a diameter less than 2 cm or with a length greater than 5 cm is used in the production of a comparable extrudate, the proportion of aligned fiber bundles may be greater. As an example, it can be mentioned that when the dough in accordance with the invention is extruded along a tube with parallel sides and which is 25 cm long and has a rectangular cross-section of 12 x 3 cm, the extrudate exhibits a fiber bundle aligned surface area of no more than 0.5 cm deep. The fiber bundle distribution in the interior of the extrudate is apparently random, as little or no arrangement is noticeable. The proportion of separate muscle fiber bundles which in this example are substantially parallel aligned with respect to each other...therefore no more than about 40%. However, if a 25 cm long tube with parallel sides that is 12 x 0.6 cm in cross section is used, the extruded product exhibits a correspondingly higher degree of fiber arrangement which is not. limited to only the surface area of the extrudate. Here, the proportion of separate muscle fiber bundles that are in substantially parallel arrangement with respect to each other exceeds 70%.

To produce an extrudate in which the proportion of separate muscle fiber bundles aligned is at least 90%, we have found that a cylindrical or parallel-sided extrusion die should be at least 12 cm long, preferably 15 to 75 cm long, and the diameter or shortest cross-sectional dimension between opposite sides, should be less than 3 cm, preferably less than 1 cm.

A particularly convenient die which is suitable for imparting sufficient shear forces to the dough during extrusion and which will obviate the need to provide an inconvenient, long passage during extrusion, is a die which has a cross-sectional area which progressively decreases along the passage in the direction of fit- seen from the dough. Such a nozzle can e.g. delineate a hollow, right truncated cone or pyramid. The taper of such a passage can end at the die exit, from which the extruded dough flows out, or the passage can become linear or divergent before the die exit is reached.

As an example of a nozzle with a tapered passage and consequently of a preferred embodiment of the invention, we use a nozzle with a rectangular cross-section and where the effective internal dimensions of the cross-section decrease uniformly from 12 x 3 cm at the entrance to 12 x 0, 6 cm at the exit, and the total length of the nozzle is 25 cm. By using such a nozzle, we are able to obtain an extrudate in which arrangement of separate muscle fiber bundles has taken place both in the surface area and throughout the entire interior of the extrudate.

When we use a die having a tapered passage in which the diameter or the shortest cross-sectional dimension between opposite sides of the passage at the exit end exceeds 1.5 cm, we find that the arrangement of the fiber bundles is usually limited to the outer part of the extrudate to a depth of about -0.5 cm, leaving behind a softer core of randomly distributed fiber bundles. Although such a product, when cooked, does not fully resemble cooked, uncut meat, it is nevertheless a product that possesses novel and commercially useful organoleptic characteristics.

When it is desired to produce a product which has a minimum measurement of the cross-sectional dimension between opposite sides or of the diameter, as stated, which is greater than 2 cm, in which the setting of separate muscle fiber bundles is present substantially throughout the product, we have found it convenient to insert in or build up in the nozzle an axially aligned plate that divides the tapered passage into two smaller passages. The plate is placed along or substantially parallel to the extrusion axis, and the two smaller passages that are thus formed are themselves tapered. In this way, axial alignment of fiber bundles is initiated before the dough is extruded in the area where it is close to each of the longitudinal surfaces within the die. As the dough continues along the passage, the degree of fiber bundle arrangement appears to increase in the dough, primarily in the area of each longitudinal passage wall, and the emerging extrudates have bands of fiber arrangement seen in transverse cross-sections, with a depth of about 0.5 cm , and each band has been limited by a pair of opposite passage walls.

It is not entirely clear why the use of tapered passages increases the degree of arrangement of fiber bundles in the extrudate, but it is believed that the differential flow characteristics of the dough, caused at least in part by a gradually decreasing cross-sectional dimension with a corresponding increase in pressure and tension before the material is extruded and as it continues along the tapered passage, leads to a build-up of shear forces that are proportionally greater than those that would be apparent in a parallel-sided die or linear passage, thus causing the alignment of a greater proportion of fiber bundles in the dough than you would otherwise expect.

It is also possible to use the nozzle with a tapered passage equipped with more than one axial plate or in reality with a series of plates, so that the original tapered passage is divided into a series of smaller tapered passages.

As already mentioned, in order to produce an extrudate, which can later be cooked into a product that resembles undivided, cooked meat in terms of texture, it is desirable that at least 70% of the separated muscle fiber bundles are substantially parallel aligned with respect to each other. The nature of the meat is complex and the behavior of the muscle fiber bundles during extrusion cannot be fully predicted in advance. The aligned fiber bundles are not necessarily Inexactly parallel to each other, nor are they, as might be expected, necessarily always aligned parallel to the extrusion axis. The separated muscle fiber bundles can thus be substantially parallel to each other, but skewed to the extrusion axis. But a microscopic examination of cross-sections on samples of extrudate produced in accordance with the invention has shown that the main amount and certainly at least 70% of the separated muscle fiber bundles can show a complete transverse section, and this confirms that they are essentially parallel to each other .

It is desirable that the dough should be consolidated after extrusion to facilitate subsequent processing. The consolidation of the extrudate can be carried out in a number of ways. In one method, the extrudate is frozen by exposing it to a temperature of less than -2°C. This method is suitable for producing products, such as steak for roasting, which are intended for sale in a raw state from a cold room. Such a steak can, if necessary, be given a solidifying treatment, such as rapid roasting on a griddle, to convert their surfaces into a rigid state which will enable the product to be processed more easily at that point (-2°C) or above. This method is also suitable for producing shaped fish products that are intended for sale in a raw, frozen state. A coating of whipped batter or bread dough can conveniently be applied to such products to improve presentation and facilitate preparation for consumption.

In another method, the extrudate is subjected to a cooking treatment, e.g. using steam bleaching or hot air, preferably until the average temperature reaches at least 65°C. The initial stage of boiling may necessitate application

of pressure so that the desired shape is maintained. This is particularly advantageous when a multi-pass nozzle has been used.

The extrudate can, preferably after consolidation, be divided into blocks, strips, cubes or pieces to be used in the production of paste or in canning, in dewatering or in freezing. When the extrudate is consolidated by heat solidification, it is particularly convenient to use a non-scratch cutter to divide it into pieces of random shape, such as is suitable for canning in sauce as a ready meal or as an ingredient in meat dishes, such as goulash. We have further found that to further mimic the shape of the roughly cut or diced, undivided meat as may occur in such canned, dried or frozen products, it is advantageous to cut or otherwise divide the heat-coagulated extrudate by a temperature of from 5 to 15°C. It seems that cutting at a lower temperature can result in too clean a cut so that the individual large pieces of meat too closely resemble specific geometric shapes, while cutting at a temperature higher than 15°C can result in excessive heating the thus completely softened extrudate and thus result in pieces of meat that are too uneven in appearance. Cutting at a temperature of from 5 to 15°C thus provides a means by which the shape of irregularly cut, large pieces of undivided meat is more closely imitated.

The invention can be used in the production of preserved meat products, such as preserved pork products, by including preservative salts in the meat mixture before its shaping and consolidation. The preservation is very fast, presumably because of the intimate contact that exists between the preservation salts and the raw meat. In this way, a cooked ham-like product can be obtained, as a large piece, and alignment of separate, cooked muscle fiber bundles throughout the majority of the piece is achieved using a multi-pass die, as described earlier. Such a product can be stored as such or cut up for sale in packages of the usual kind. Pork products can, if desired, be formed with a surface layer of tissue fat attached to the underlying meat, to mimic the appearance of ham.

Meat products obtained by the method according to the invention can be dewatered with conventional means. Furthermore, many of the products, especially those made from beef or chicken, when dewatered, give products that reabsorb water relatively quickly. By drying cooked meat products obtained according to the invention, pieces of meat can be obtained which are suitable for mixing into thick meat soups and sauces, and in dewatered flour containing meat soup-forming ingredients. In contrast, dried, cooked, natural cuts of meat are usually not satisfactory for such an application, because of their relatively slow rate of taking up water in such a medium.

The invention is illustrated by the following examples.

EXAMPLE 1

This example illustrates the preparation of a dewatered, improved beef product.

Preparation of cooked, texture-forming component.

Frozen Argentinian boneless topside of beef was

cooled at -2°C, cut into quarter kilo pieces and cooked at 120°C for 60 minutes. The broth obtained was concentrated and kept chilled until it was subsequently used as an addition to the dough before extrusion. The cooked pieces of meat were rubbed for 20 seconds in a bowl mincer with a blade setting that provided a gap of 4 mm from the bowl wall. The obtained fibrous material was shown by microscopic examination to consist mostly of muscle fiber bundles with an average length of 1 to 2.5 cm and an average diameter of about 1 mm. The proportion of cooked, separated muscle fiber bundles having these dimensions represents about 90% by weight, expressed on a solids basis, of this fraction of cooked beef. The rest are fragments of fibres, fiber bundles and other meat tissue structures.

Preparation of powdered raw meat composition and dough.

Frozen Argentinian boneless topside of beef was chilled at -2°C, cut into quarter kilo pieces and passed through a 3 mm hole shredding plate. The effect of this was to provide coarsely ground raw meat particles with an average size of around 3 mm, surrounded and thoroughly mixed with emulsified, finely divided, raw meat with a much smaller particle size. The comminuted meat emulsion was thoroughly mixed for 15 minutes with salt, monosodium glutamate, polyphosphates and flavorings, and then mixed for an additional 2 minutes after the addition of an appropriate amount of the separated, cooked, muscle fiber bundle fraction, and finally mixed for 6 minutes after the addition of concentrated broth, as they. last 60 seconds were under vacuum.

The minced meat thus obtained had the following composition:

Extrusion and drying.

The dough was extruded at room temperature under a pressure of about 2 kg/cm from a meat die provided with a die with a rectangular section of 12 x 3 cm at the insertion point and tapering to 12 x 0.6 cm at the exit point and with a length of 25 cm. The extruded slices of improved meat (the extrudate) were heat coagulated by exposing them to an air stream having a dry ball temperature of 110°C and a wet ball temperature of 85°C, for 20 minutes. During this time there was a reduction in weight of approximately 10%. The coagulated sheets of the extrudate were cut to a convenient size with a non-scratch cutter and dried to a moisture content of 5% by weight on a belt dryer for 4 hours at a temperature of 80°C.

The product thus obtained was capable of reabsorbing water rapidly in hot water, and when cooked closely resembled, in texture and appearance, pieces of undivided cooked beef top of a similar size.

Microscopic examination.

Transverse, frozen sections of the extrudate after heat coagulation were examined under the microscope with regard to the distribution and orientation of muscle fibers and muscle fiber bundles. The following table shows the mean number of measured muscle fiber bundles that were observed to be parallel to each other. Comparable figures for muscle fiber bundles that are apparently not aligned with the main body are also given. It should be noted that parallel alignment was inferred from transverse sections of the extrudate (taken at right angles to the extrusion axis) by recording the number of muscle fiber bundles that were circular in outline and thus indicated that they had been cut at right angles with regard to their respective axes. It was further observed that very few individual fibers that stood out were visible in these sections.

It will be seen from the above results that from 86 to 97% of the muscle fiber bundles were in parallel arrangement with each other and with the axis of extrusion. The average value was 92%.

EXAMPLE II

This example illustrates the preparation of a dewatered, improved chicken product.

Preparation of cooked, texture-forming component.

Undivided, fresh chicken was cooked at a temperature of 120°C for 60 minutes, and the resulting broth was concentrated and kept chilled until it was to be used in the subsequent addition to the dough before extrusion. The cooked chicken was then deboned and the cooked chicken meat was rubbed for 20 seconds in a bowl mincer with the blades set 4 mm apart from the bowl wall. The fibrous material obtained was found by microscopic examination to consist of bundles of muscle fibers with an average length of 0.2 to 0.5 cm and a diameter of about 1 mm, and represented about 55% by weight, expressed on a solids basis , of this cooked chicken fraction. The fibrous material also contained other particles of a fibrous nature.

Preparation of powdered raw meat composition and dough.

Fresh, raw chicken was passed through a mincing plate with a hole diameter of 3 mm, and the minced meat was carefully mixed with finely powdered raw chicken broth, salt and monosodium glutamate. A portion of the boiled muscle fiber bundle fraction was finally added and the mixture was completed under vacuum.

The chicken mince thus obtained had the following composition:

Extrusion and drying.

The chicken meat dough was extruded, coagulated and dried as described in Example I, and was found to have an aligned, fibrous structure similar to that observed in the corresponding beef product.

EXAMPLE III

This example illustrates the preparation of a canned, improved beef product.

Preparation of cooked, texture-forming component.

The fiber bundle fraction of the cooked beef was prepared in the manner described in Example I.

Preparation of powdered raw meat composition.

Quarter kilo pieces of raw, frozen, Argentinian beef were bowl minced with a 1 mm blade setting, along with added ice for 40 seconds (40 revolutions of the bowl), then flavorings, salt and polyphosphate were added, and chopping was continued for another 60 seconds (60 revolutions). Fat was added and bowl chopping was continued for 100 seconds (100, revolutions). The temperature in the mixture had then risen to around 10°C. The average particle size of the raw meat component was less than 2 mm.

Mix to form a dough.

The minced raw meat component and the rubbed cooked fibrous component were thoroughly mixed for 6 minutes in a Z-arm mixer, a vacuum being applied for the last 60 seconds to remove air from the thus formed dough.

This minced meat had the following composition:

Extrusion and canning.

The meat dough was extruded under the conditions described in Example I and was found to have a similar structure with respect to the parallel axial arrangement of the separated cooked muscle fiber bundles.

The extrudate was heat coagulated by exposing it to heavy steam for 5 minutes. The coagulated surfaces of the extrudate were cut to convenient sizes with a non-scratch cutter and then canned in a meat sauce with vegetables. Each of the pieces of meat was shown by microscopic examination to contain individual muscle fiber bundles, 90% of which were essentially parallel to each other.

EXAMPLE IV

This example illustrates the preparation of a canned, improved pork product.

The cooked texturizing component and the powdered raw meat composition were prepared from pork in the manner described in Example III. The ingredients were mixed in a Z-arm mixer, and the pork dough thus obtained had the following composition:

The dough was extruded, heat coagulated, diced and canned in the manner described in Example III. The product was shown by microscopic examination to contain separate bundles of muscle fibers that were between 0.2 and 0.5 cm long, and most of which were substantially parallel to each other.

This example illustrates the preparation of a canned, improved chicken product.

The procedure described in example III was repeated using chicken meat instead of beef, and the kyl-lingk jøtt dough obtained after mixing cooked and raw ingredients had the following composition:

The chicken mince was extruded, heat coagulated,

diced and canned as described in Example III,

and it was found to have a structure with respect to fiber bundle arrangement similar to that observed in the corresponding

end beef product.

EXAMPLE VI

This example illustrates the production of a frozen, improved fish product.

Preparation of raw texturizing component and powdered raw meat composition.

Pieces of filleted cod were passed through a perfo-

fixed plate that had holes with a diameter of 1.5 mm. The finely divided fish thus obtained was found by microscopic examination

to consist mainly of separate muscle fiber bundles intermingled

with other fibrous remains with dimensions smaller than 2 mm, and a colloidal emulsion of very finely divided particles of fish muscle. Production of fish mince.

The minced fish containing separated muscle fiber bundles in the raw state was mixed with polyphosphate and heated in a Z-arm mixer to obtain a dough which, after air removal, was extruded through a die 2 x 1 cm in rectangular cross-section.

diameter and 10 cm long.

The extruded fish was shown by microscopic examination to have an aligned structure, in which around 90% of the individual, separate muscle fiber bundles were aligned with each

second and with the extrusion axis.

The strip of extruded fish was cut into pieces which

were 6 cm long and were frozen, coated with breadcrumb mixture as used in the production of fish croquettes, and it was lightly fried and then stored in a deep freezer until it was to be consumed. After frying for 3 minutes in base oil, the improved fish croquettes were found to have, when consumed, a similar texture and appearance to fish croquettes prepared from whole fish fillets.

EXAMPLE VII

This example illustrates the production of improved beef suitable for canning or for the production of meat pâté. 1. Production of texture-forming component consisting of substantially separated, boiled muscle fiber bundles.

a) Frozen bog lumps and pieces were cut into cubes of about 10 cm and then thawed at 4°C for 18 to 20

hours.

b) The thawed cubes were then cooked in a pressure cooker at about 7 kg overpressure and 116°C for 40 minutes. It boiled

meat was allowed to cool at room temperature (18°C) and was then stored at 4°C until consumption.

c) The cooked meat cubes were shredded into fibers using a Meissner bowl chopper - model RZN 33/106 -

at a bowl speed of 10 revolutions per minute. To ensure minimal cutting of the meat, the blade distance from the bowl wall was increased to 2 mm, instead of using the standard setting of 1 mm. The separated muscle fiber bundles thus produced were from 12 to 25 mm in length and were 0.5 to 1 mm in diameter. Lumps and gristle were removed by hand from the texturizing component prior to subsequent mixing to form the dough.

2. Preparation of powdered raw meat composition.

a) Frozen, boneless cow meat and beef pieces were cut into cubes of about 5 cm, thawed and then stored at

4°C before pulverization.

b) The cube was chopped again using a Meissner bowl chopper, and this time with a setting between

leaf and bowl wall of 1 mm. Salts and ice were added in this step and the mixture was chopped for 5 minutes (50 revolutions) to form an emulsion with the finely dispersed fat and one was

o careful that the meat temperature did not exceed 10 C.

3. Preparation of dough.

3.2 kg of the powdered raw meat composition was mixed with 1.4 kg of the texturizing component for 3 minutes in a Hobart mixer (model A-200-T) using a dough hook.

The dough had the following composition:

The total amount of solids in the dough thus formed was 39.96%, of which 18.73% was fat, 18.73% was protein and 2.5% was returned as ash.

4. Dough extrusion.

The dough was extruded using a Matador sausage press fitted with a rectangular cross-section tapering nozzle, with a dimension at the entry point of 6.3 x 15 cm and at the exit point of 1.27 x 15 cm and a length of 33 cm. The extrudate was received in a trough as a mud and then steamed for 6 minutes at 100°C in an open steam boiler.

Some of the cooked meat was finally ground by passing the heat-set mud through a 3.2 mm plate, while the remainder was diced approximately 2.5 cm in size.

EXAMPLE VIII

This example illustrates the production of processed beef that is suitable for canning or for the production of meat paste.

The procedure in Example VII was repeated using different proportions of the same ingredients, and the dough had the following composition:

EXAMPLE IX

This example illustrates the production of improved beef suitable for canning or for the production of meat pâté.

The procedure from Example VII was repeated using different proportions of the same ingredients, heart meat was used instead of beef pieces, and kidney fat was also added. The dough had the following composition: Weight% Analysis

EXAMPLE X

This example illustrates the production of improved beef suitable for canning or for the production of meat pâté.

The procedure from Example IX was repeated using different proportions of the same ingredients, and the dough had the following composition: Analysis

EXAMPLE XI

This example illustrates the production of improved beef suitable for canning or for the production of meat pâté.

The procedure from Example IX was repeated using different proportions of the same ingredients, and the dough had the following composition: Analysis

EXAMPLE XII

This example illustrates the production of improved beef suitable for canning or for the production of meat pâté.

The procedure from Example IX was repeated using different proportions of the same ingredients, and the dough had the following composition: Analysis

EXAMPLE XIII

This example illustrates the production of improved beef suitable for canning or for the production of meat pâté.

The procedure from Example VII was repeated using the same ingredients with the same quantity ratio, but with the additional process step of removing air in the dough during the last minute of mixing using a vacuum.

The final product obtained had a more compact constitution and the fiber bundle arrangement was more divergent due to the improved chewing texture of the product when consumed.

EXAMPLE XIV

This example illustrates the preparation of improved roast beef.

A mince dough was prepared as described in Example IX, and the dough also contained a proportion of chopped vegetables and flour, and it was extruded through a cylindrical die 25 cm long and 3 cm in diameter into a cellulose casing.

The dough had the following composition:

The stuffed casings were then heated to an internal temperature of 70°C in a Proctor and Schwartz dryer. The heat-congealed meat was, when it was cold, cut up into small pieces of steak.

EXAMPLE XV

This example illustrates the production of improved beef.

The procedure of Example XIV was repeated using different proportions of the same ingredients.

The dough had the following composition:

EXAMPLE XVI

This example illustrates the preparation of improved roast beef.

The procedure from Example XV was repeated using the same proportions of the same ingredients, but with the additional process step of removing air in the dough during the last minute of mixing, using a vacuum.

The finally obtained product had a more compact constitution and the fiber bundle arrangement was more divergent due to the improved chewing texture of the product when consumed.

COMPARISON TESTS CONCERNING TASTE ANALYSIS OF SAMPLES OF REFORMED MEAT

F remqanq small tea

Diced meat (samples A and C) was heated in the applicant's standard sauce for 10 minutes. Each member of the tasting jury was given three pieces of each sample on two heated white porcelain plates. The tasting was done under subdued red light to completely blur any slight difference in appearance between the samples, and the order of the tasting was random.

The 48 members of the taste jury who took part in the tests varied in terms of qualifications, but all had some experience with regard to taste analysis of meat texture and were familiar with the form of assessment and the grading method.

Results

Average marks, set by the jury, for each of the 11 parameters are reproduced in Table 1 together with an assessment of the difference between samples required for statistical significance at the 5% level.

Recent analysis of data from many previous, similar judgments by test juries has indicated that variation between samples can be largely explained on the basis of three "factors" derived from the 11 parameters. These factors were termed "juiciness", "aroma" and "tenderness".

The calculated factor grades for the two samples are reproduced in table II.

Conclusion

The samples have J.ik aroma and are not very different in terms of texture. However, they are decidedly different both in terms of "resistance" and "elasticity", and this, seen in conjunction with a similar tendency for "chewability" grades, must account for the significant difference in the "tenderness" factor grade.

Claims (8)

1. Process for the production of a shaped, consolidated meat product, comprising the following steps: I) making a divided mixture of raw meat, comprising an intimate mixture of raw, lean meat, fat and water, the meat component of the mixture having a average particle size of less than 2 mm, II) comminuting cooked meat to provide a texturizing component of separated muscle fibers bundles, each fiber bundle being from 2 to fiO mm long and from 0.2 to 2 mm in diameter, III) to mix from 30 to 97.5% by weight of the "divided mixture of raw meat and from 2.5 to 70 % by weight of the texturizing component for providing a minced meat having, by weight, a total moisture content of from 50 to 80% and a total fat content of from 1 to 40%, characterized by the further steps: IV) extruding the dough through a cylindrical or parallel-sided extrusion die with a length of at least 12 cm and a shortest cross-sectional dimension between opposite sides of less than 3 cm, for the formation of a shaped extrudate where the proportion of muscle fiber bundles which are in an essentially parallel arrangement with each other is from 70 to 100%, and V) to consolidate the extrudate by freezing or heat-solidifying in a manner known per se. 2. Method as stated in claim 1, characterized in that a nozzle with a rectangular cross-section is used with the dimensions 12 x 3 cm at the inlet, which tapers to 12 x 0.6 cm at the outlet over a length of 25 cm. 3. Method as stated in claim 1, characterized in that each fiber bundle is divided into a length of from 3 to 25 mm. 4. Method as stated in any one of claims 1 to 3, characterized in that the dough is prepared by mixing from 50 to 80% by weight of the divided mixture of raw meat with the texturizing component. 5. Method as stated in any of the preceding claims, characterized in that the dough is prepared by mixing the divided mixture of raw meat with from 20 to 45% by weight of the texturizing component. 6. Method as stated in any of the preceding claims, characterized in that a minced meat with a total fat content of 5 to 25% by weight is used. 7. Method as stated in any of the preceding claims, characterized in that a minced meat is used which additionally comprises coarsely ground, raw meat with a particle size of from 2 to 15 mm. 8. Method as stated in any of the preceding claims, characterized in that parallel fiber arrangement is carried out by passing the minced meat through a nozzle with a cross-sectional area that decreases progressively along the passage in the direction traveled by the dough to an outlet which has a diameter, or shortest distance between opposite sides, of less than 1 cm.