US 20090226586 A1
A method for separating lean meat from lean meat-containing material includes combining a particulate material with fluid, subcritical carbon dioxide at a pH of about 7 or less and a pressure of about 600 psig. The material and fluid is introduced into the vessel and is separated into low density and high density fractions. The material from the low density fraction is removed via an outlet and has a higher percentage of fat than the material introduced into the vessel. The material from the high density fraction is removed via an outlet and has a higher percentage of lean meat than the material introduced into the vessel. The vessel can include a centrifuge or a vessel disposed toward the vertical having an upper and lower outlet, wherein the separation is achieved by the respective densities of the material, and the natural or an artificial gravity field.
1. A method for separating lean meat from lean meat-containing
combining a particulate material having lean meat and fat with a fluid comprising subcritical carbon dioxide, wherein the combination of the material with the fluid has a pH of about 7 or less;
introducing the material and fluid into a vessel to fill the vessel, wherein the vessel has first and second outlets, and allowing the material to separate into low density and high density fractions within sections of the vessel;
removing material from the low density fraction via the first outlet of the vessel, wherein the material removed from the first outlet has a higher percentage of fat than the material introduced into the vessel; and
removing material from the high density fraction via the second outlet of the vessel, wherein the material removed from the second outlet has a higher percentage of lean meat than the material introduced into the vessel.
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extracting the material removed from the low density fraction of the first vessel;
introducing the extracted material into a second vessel having a first outlet and a second outlet;
allowing the material to separate into low density and high density fractions within sections of the second vessel;
removing material from the low density fraction via the first outlet of the second vessel, wherein the material removed from the first outlet has a higher percentage of fat than the material introduced into the second vessel; and
removing material from the high density fraction via the second outlet of the second vessel, wherein the material removed from the second outlet has a higher percentage of lean meat than the material introduced into the second vessel.
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16. A method for separating fat from material containing lean meat and fat, comprising:
introducing a material containing lean meat and fat to a conduit containing a rotating and tapering transfer mechanism;
introducing carbon dioxide to the conduit at a pressure and temperature below the critical temperature and critical pressure for carbon dioxide;
transferring the material and carbon dioxide along the conduit by rotating the tapering transfer mechanism; and
separating carbon dioxide with fat through an outlet disposed along the conduit to produce material product containing a lower percentage of fat than the material introduced into the conduit.
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This application is a continuation of application Ser. No. 11/004,669, filed Dec. 2, 2004, which is a continuation-in-part of PCT/US03/17643, filed Jun. 3, 2003, which claims the benefit of U.S. Provisional Application Nos. 60/438,546, filed Jan. 7, 2003; 60/433,526, filed Dec. 13, 2002; 60/429,644, filed Nov. 25, 2002; 60/427,516, filed Nov. 19, 2002; 60/424,388, filed Nov. 5, 2002; 60/422,949, filed Oct. 30, 2002; 60/411,138, filed Sep. 16, 2002; 60/391,702, filed Jun. 24, 2002; 60/388,067, filed Jun. 10, 2002; 60/385,710, filed Jun. 3, 2002. All the above applications are herein expressly incorporated by reference.
The present invention relates to the decontamination of any goods, solid or liquid, including meat, with the use of carbon dioxide at high pressure.
At a time when there is increasing consumer demand for natural, and if possible organic, foods, and an increasing regulatory requirement for the reduction or elimination of artificial chemicals and preservatives; it is alarming to note that many proposed methods for decontaminating meat rely on the addition of chemicals not normally found in such foods.
One such food is a beef product known as Lean Fine Textured Beef (hereinafter “LFTB”). LFTB can be harvested from discarded “fat” cut from carcasses. During the process of boning a carcass, the external fat layer can be removed. During the process, a significant amount of lean meat can be cut from the carcass and discarded with the fat. To recover the lean meat, the discarded fat can be heated to about 109° F. The heated fat can be processed in a centrifuge that separates the fat from the lean meat. The lean meat is then frozen and chipped into small flakes. The finished product, known as LFTB, is then stored in a frozen condition and can later be added to ground beef, for example. The temperature of the LFTB during the separation process does not exceed the temperature that a carcass would normally experience post mortem. As a result, pathogens and bacteria that are present on the surfaces of the carcass prior to boning can result in bacteria being present in the LFTB.
A need exists to more effectively kill, reduce or remove the microbial population on any processed meat, or any other good, liquid or solid, to eliminate sources of cross contamination and recontamination, while simultaneously allaying the concerns of using artificial chemicals. A need also exists to more effectively separate fat from lean meat.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
A method for separating lean meat from lean meat-containing material includes combining a particulate material having lean meat and fat with fluid, subcritical carbon dioxide at a pH of about 7 or less. The material and fluid is introduced into a vessel. The material is separated into low density and high density fractions within sections of the vessel. The material from the low density fraction is removed via a first outlet, and the material removed via the first outlet has a higher percentage of fat than the material introduced into the vessel. The material from the high density fraction is removed via a second outlet, and the material removed via the second outlet has a higher percentage of lean meat than the material introduced into the vessel. The vessel can include a centrifuge or a vessel disposed toward the vertical having an upper and lower outlet, wherein the separation is achieved by the force of the natural or an artificially created gravity field, such as in a centrifuge, acting on the material, and the fractions are formed based on the respective densities of the material. The separation may be carried out at elevated pressures, such as at a maximum of about 600 psig, or about 500 psig.
The density of the fluid can be controlled, and can either be increased or decreased to control the separation. The particle size of the material affects the efficiency of separation, since the smaller the particles, the more likely that the particle will be either mostly lean meat or mostly fat. For example, larger particles may have just enough of a majority of either lean meat or fat to separate in one direction or the other. As the particles are reduced in size, each individual particle will have a greater majority of either lean meat or fat, and will tend to separate quicker. At the very extreme, when particles are reduced to the molecular level, each particle will be either all lean or all fat.
In one embodiment, the fat content of the processed ground beef is determined by particle size, for example, by reducing the particle size, separation will be more thorough, and the lean meat will be lower in fat content. Therefore, the fat content of the lean meat product can be determined by controlling the particle size. The larger the particle, the more fat will be retained in the lean meat stream, and the smaller the particle, the less fat will be retained in the lean meat stream. The density of the fluid can also be manipulated to affect the separation efficiency.
In one embodiment, the fat content of quantities of meat derived from both cow and steer is removed leaving lean meat, and the fat that was removed is replaced by fat derived from steer to control the amount of fat content in lean meat product.
One embodiment of the present invention is directed to a method and apparatus for decontaminating goods, such as meat, by using a “shock” method (hereinafter AST) involving immersion of meat in a high pH alkaline solution followed by immersion in a low pH acid, such as carbon dioxide and water at higher than atmospheric pressures. Alternatively, the method can incorporate irradiation of meat.
In one embodiment, a decontamination method for goods, such as meat, is disclosed that exposes the goods to a low pH followed by exposure to irradiation, such as x-ray, gamma, or e-beam.
In one embodiment of the invention, the high pH solution can include calcium and hydroxide ions.
In one embodiment of the invention, high pH alkali such as calcium hydroxide solution is sprayed onto meat portions in a manner so as to ensure a substantially complete covering of the outer surfaces of the meat. The pH at the surface of the meat is elevated to a pH of about 12 to about 14. The bacteria are subjected to the high pH and are either killed by the high pH or become acclimatized to it. After the meat has been exposed to high pH conditions for an effective period of time, the meat can then be immersed in a low pH acid, such as can be provided with blending carbon dioxide and water at a suitable temperature and pressure. High pressure causes the formation of carbonic acid. The probability of killing bacteria is almost certain since the rapid change of pH from about 12 to about 3 shocks the bacteria, and they are unable to acclimatize to the rapid pH change. Such microorganisms killed may be E. coli 0157:H7, Salmonella, Listeria monocytogenes, and other pathogens.
In another embodiment, an alkali metal chlorite is added, either as a solid or in solution, to the meat that is to be decontaminated, prior to exposure of the meat to an acid, such as carbonic acid, that is generated by dissolving carbon dioxide in water at a suitable high pressure to cause a lowering of the pH. The benefit of applying an alkali metal chlorite prior to addition of the acid and not with the acid is that the alkali metal chlorite is not wasted prior to the time when it is needed. Applying a solution of a chlorite together with an acid will result in a waste of sodium chlorite. Representative alkali metals include potassium and sodium.
The microbiocidal effect is noticeable at acidic pH values below about 7.0 and more pronounced below about 4.0. The microbiocidal effect is maximized when the pH of the alkaline solution is about 12 to about 14 and is followed by immersion in a solution of dissolved carbon dioxide in water such that the pH of carbonic acid is less than 7, or about 2 to about 3.
In another embodiment, the surface of the meat can be kept substantially at about 28° F. to about 40° F. to avoid freezing. Chilling of the meat can be accomplished by using the carbon dioxide in a form that provides substantial latent heat of evaporation such as a dense gas, liquid or solid.
Exposure of meat to oxygen can produce undesirable brown color in meat due to oxidation. It is therefore desirable to substantially prevent oxygen from contacting goods, such as meat. Eliminating the presence of oxygen as much as possible during processing, handling, storage, and packaging can produce meat having an extended storage or shelf life.
In another aspect of the present invention, a process to reduce bacteria, including E. coli 0157: H7 and other bacteria and pathogens, to a level within desirable limits, while also simultaneously controlling the water content in meat and adjusting the fat content in meat, is provided. Furthermore, beef trim that has been removed from beef cuts and carcasses during the normal process of disassembly and is either presently disposed of by rendering, or alternatively processed by Beef Producers of Iowa (hereinafter “BPI”) to produce a product known as lean finely textured beef (hereinafter “LFTB”), can be processed according to the invention.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
The decontamination, pasteurization, and processing apparatus and methods described below can be for goods, such as meat, boneless or otherwise, with the optional use of any additional substance(s), liquid(s) and/or gas(es), which use carbon dioxide and water in any selected, relative, and/or measured quantities and at any suitable pressure, combined together in an effective manner so as to produce carbonic acid. Additionally, the water (moisture) content of the goods, such as beef or poultry meats, can be measured and controlled according to the methods disclosed.
One aspect of the invention provides water content standards for meat. The water content standards can be used to approximate the naturally occurring level of moisture in any meat. The composition of fresh boneless meat, harvested from an animal, can be reduced to substantially two components, lean meat, and fat. Both lean meat and fat can contain a large percentage of water. A more extensive analysis of meat, harvested from any animal used as food intended for human consumption, can include elements such as hydrogen, oxygen, carbon, and metals such as iron, calcium, sodium and potassium. Elements that comprise the meat harvested from the animal can be measured and stored in a computerized system and database that can be accessed for the beneficial evaluation of the data and also to establish water content standards for meat composition to enable the definition of limitations of any particular element or compound that can cause harm to any human that may consume the meat. For example, limits of the metal mercury are already established. Water can represent the largest single component by weight of the meat or fat. Water can evaporate readily when exposed to air, and particularly when exposed to refrigerated air. Water loss in refrigerated air may be as much as about 1% to about 2% for every 24-hour period when the fresh meat is exposed to the refrigerated air. Water loss can occur throughout the duration of meat processing. Water loss can represent a significant loss, and thus reduce profits. Accordingly, it is desirable to avoid and/or control the water content in meats. The present invention can provide methods for the control of the water content in meats.
The present invention provides a method that includes measuring the water content of fresh meats harvested from animals. The data derived from the measurements can be transferred to a computerized database for use in developing a set of water content standards (standards) that can provide the water composition for any meat from any group of animals that are related by one or more characteristics. The standards can then be used as a reference to control the water content at any given level of meat harvested from an animal belonging to the corresponding group or category, even when the water content of the meat is not directly measured. The standards are derived from data previously obtained from different animals constituting the same group of animals as the animal from which the meat was harvested.
In order to enable the continued improvement and accuracy of the standards, the data can be integrated and/or transferred between several databases that are used in the meat production industries. In particular, a corporation known as Global Animal Management, Inc., (hereinafter “GAM”) has developed a system enabling the collection and storage of data associated with, for example, genetics, ancestry, birth, lifespan, food consumption, food conversion efficiencies, medications, and growth characteristics. The GAM system can evaluate the performance of medications and any variations in performance. Solutions can be found and problems resolved that otherwise may never have been identified. The GAM database can be directly interfaced or integrated with the standards database according to the invention, to enable the evaluation of other factors that will enable resolution of problems. Another company called Systems Integration Trading, Limited, (hereinafter “SITL”) provides equipment and methods that can be incorporated with the present standards database of the invention. Additionally, a corporation based in Germany and known as E+V Technology GmbH, (hereinafter “EVT”) has developed a carcass grading and classification system. The EVT system uses data acquired from a single digital image to determine the size, weight, conformation and other qualities of an animal carcass. The accuracy and speed of the EVT system is vastly more accurate and efficient than the corresponding accuracy and productivity of data and measurements acquired manually with human labor. Data and measurements are accumulated in the database over a period of time, and wide variations in carcass data enable rapid classification of every carcass. This is achieved by comparing the data acquired from the digital image of the carcass with the historical data which establishes the “best fit” and then classifies the carcass to be used in the most efficient manner.
The systems noted above can be combined and/or integrated for the sharing and processing of data.
According to the invention, water content data is categorized and/or associated with data detailing any notable characteristics of the animals. All animals in any one grouping have at least one characteristic that is shared between all animals. For example, animals may be categorized according to an age range, weight, sex, genetic composition and birthplace and the measured water content data is compiled in a computer database. Any number of categories can be established and the water content measurement data of meat samples extracted from animals from the same grouping can be collated so that it can be compared, combined and/or used with other data acquired from other databases, such as the GAM and EVT databases.
Measurement data acquired from animals can be transferred and stored in the standards database so as to create a suitably extensive database data that is representative of each category of animal, enabling the determination of the naturally occurring water content in meat that can then be used for the accurate control of water content in meat.
The database created according to the invention can include animal composition data detailing the elements and/or compounds constituting any meat derived from the animal. The water content of fat as distinct and separate from lean meat or muscle can also be analyzed and the associated data for selected animals recorded in the database accordingly. Data detailing the analysis of the composition of lean meat or muscle for all animals in all categories can also be recorded and such information used in any manner, such as to control the water content.
RFID devices can be injected into an animal, or attached to a tag to an animal extremity to identify an individual animal. Another system utilizes an animal's eye retina to enable accurate identification of an animal. Data associated with each animal can then be recorded in a database.
In one embodiment of the present invention, an animal is grouped into a category before slaughter, or immediately thereafter, and assigned a water content standard representing the natural water proportion of the meat or the fat. The animal can be processed according to any method and at all times, any products derived from the animal can be tracked to the animal, and the water content throughout processing can be measured and adjusted to within any percentage. For example, in one embodiment, the meat flow rate is measured along with any water added to the meat, and the water content of the meat is also measured. Typically, the meat may have lost some water through evaporation or otherwise. The added water may exceed the difference between the natural proportion of water (as determined by the water content standard) and the measured water content of the meat. Thus, to reduce the water content of meat to its natural proportion, water can be removed. The removed water is measured and metered to leave behind that amount that will not cause the meat to have any water in excess of the allowable. Thus, after processing, the meat contains its natural proportion of water or any other desired amount. The meat may be further measured after processing to ensure the water content is within the desired amount. Alternatively, in other embodiments, rather than achieving the natural proportion of water in meat, the amount of water can be any amount allowed that can also exceed the natural proportion. The meat can be packaged in a low oxygen environment wherein the oxygen level is lower than air, and the package can be provided with a label indicating the amount of added water or the amount of water that is in the meat.
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The processes disclosed herein may be applied to any meat. The processes can also be applied to paper pulp for bleaching purposes and/or for killing any type of molds that may otherwise survive the normal process of paper production or the production of timber building products manufactured from wood chips. Any goods may be processed with the apparatus and methods disclosed herein. Representative examples of liquid and solid goods that can be processed and/or decontaminated by the apparatus and methods disclosed herein are listed below. Some solids may also be regarded and processed in a manner that is suitable for liquids (such as ground meats) and some liquids may be regarded and processed in a manner that is also suitable for solids. Representative goods are listed below under the headings of 1) “Substantially Liquids;” and 2) Substantially Solids”:
1) “Substantially Liquids” includes: meats; sausage; seeds and grains; animal feeds; slurries; paper pulp used in production of paper products (slurries); water for drinking; water (e.g., contaminated water); sewage.
2) “Substantially Solids” include: salami, meats; hams; frankfurters; poultry (whole, dressed and poultry pieces); vegetables and fruits [hard and soft] (e.g., lettuce, cauliflower, tomatoes, apples, melon, pears, oranges, broccoli); fish (whole sea fish and freshwater, gutted or otherwise); beef primal portions (e.g., strip loins, round, rump, tenderloin); timber or wood chip raw materials used in building materials; waste food products (e.g., waste from hotels, restaurants for recycling into animal feeds).
The term GRAS refers to “Generally Regarded As Safe” and is understood and used by the USDA, FDA, and those in industry to describe substances that can be used with goods as additives. Representative examples of GRAS substances are: sodium hydroxide, sodium chloride, sodium chlorite, potassium chloride, and potassium chlorite. These substances can be added in any form, before, during, and after treatment with carbon dioxide and water according to the invention.
The term “alkaline solution” includes a solution of an alkali substance, such as ammonium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, tri-sodium phosphate, and any other suitable alkali. These substances can be added in any form, before, during, or after treatment with carbon dioxide.
The term “gas pressure” or “water pressure” refers to any pressure that is suitable or effective for the particular application, and may be controlled within any of the following pressure ranges, or at any other suitable or effective pressure:
Representative approximated values of carbon dioxide density, pressure, temperature and corresponding pH are shown in the following table (Table 1):
One embodiment of the present invention includes a method for the treatment of goods, such as meat, with a high pH, alkaline solution, followed by treatment with a low pH, acid solution, wherein the acid can have a “temporary” low pH value. The pH of the acid can be below about 7, including a pH of about 1 to about 3. Optionally, the high pH alkaline solution or the low pH acid solution can include a GRAS substance. The acid can have a temporary low pH for the period of time during which it is being used to decontaminate the meat. The pH of carbon dioxide and water, for example, will increase when the pressure is reduced; thus, the low pH level can be temporary. Water and carbon dioxide can be mixed in any proportions, such as 3 moles of carbon dioxide mixed with 2 moles of water. The pH of carbon dioxide and water is about 4 to about 5 when about 0.1 mol. (4.4 g) of carbon dioxide are mixed with about 10 mol. of water (180 g), and about 2 to about 3 (pH) when about 20 mol. of carbon dioxide (88 g) are mixed with about 10 mol. of water. However, in order to achieve these low pH levels, the carbon dioxide should be capable of dissolving into the water, which occurs at a pressure of about 750 psia at about 10 degrees centigrade, for example. Exposure of goods, such as meat, to carbon dioxide and water, can be followed by exposure to overwhelming quantities of liquid or dense carbon dioxide for the purpose of decontamination. Table I shows the effects of temperature and pressure on pH. In addition, low pH levels can be achieved by adding compounds, such as sodium chlorite, sodium chloride, and sodium hydroxide. Other substances can be naturally occurring gases, which can evaporate when the process of decontamination has been completed and the finished and processed product is exposed to ambient atmospheric pressure. Alternatively, naturally occurring liquid or solid processing agents, such as water and/or salts, such as sodium chloride, can be used. Any substances that will weaken pathogens and render them labile can be used.
The use of high pressure carbon dioxide, enabling enhanced solubility in water to create carbonic acid having a pH less than about 3.0, can be regulated to effectively achieve the desired kill rates while eliminating the potential deleterious effects of retaining low pH acid in the goods. In one embodiment, lactate and ethanol, in suitable quantities, are added to the goods intended for processing, in combination with carbonic acid at high pressure. After the process has been completed, the pH of carbonic acid can be increased when the pressure is lowered to atmospheric pressure. This provides a significant advantage when compared with the use of acid that remains highly acidic at atmospheric pressure, such as hydrochloric acid.
Additives such as sodium chlorite, ethanol, acetate, citrate, and organic acid(s), such as citric acid, can also be used by adding selected quantities, at the appropriate stage, which may be applied in multiple, sequential stages, to achieve the desired results.
The decontamination system according to one embodiment of the invention can include a first high pH stage apparatus and a second low pH stage apparatus. The low pH apparatus can use carbon dioxide at a pressure above ambient pressure to produce carbonic acid.
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A vertically disposed container section 206 is connected (at the opposite lower portion of the conduit 216). The container section 206 has an open end located directly under a conveyor 200. The opposite lower end of container section 206 is open to the inclined conduit 216 so as to allow the passage of meat from the vertical container section 206 into the inclined conduit 216.
The continuous, horizontally disposed belt conveyor 200 is arranged to carry the meat 202, directly from a carcass disassembly room, for example. The conveyor 200 is arranged so that one end will terminate above the opening of the container section 206. When the conveyor belt 200 passes around the conveyor belt roller 204, the meat 202 will drop downwardly and into the open end of the vertically disposed container section 206.
The container section 206 includes an inlet port 228 for the introduction of any suitable high pH alkaline solution. Any number of spray nozzles 224 can be installed along the interior walls of container section 206. Spray nozzles 224 can provide a spray 226 of high pH solution thereby exposing the surfaces of the meat to the high pH solution.
Alkaline solution can be maintained in the inclined section 216 and in the vertical container section 206 at any suitable level, depicted by numbers 214 and 240, respectively, with the use of any suitable level instrumentation. A drain (not shown) can be located at any convenient location to drain solution from the container 206 or inclined conduit 216. The variable speed drive motor 238 can control the amount of exposure time of the meat to the high pH solution by increasing or decreasing the speed of rotation of screw 236. When the meat exits the constriction portion 234 of the inclined conduit section 216, the meat falls into the storage container 222. From the storage container 222, the meat 232 can be transferred to any pressurized low pH stage apparatus described below. Alternatively, the storage container 222 may be omitted, in which case the meat exiting the apparatus can pass directly into the low pH stage apparatus. In other embodiments, there may be one or a plurality of operations before and after the high pH and the low pH stage apparatus. These auxiliary unit operations can perform various functions on the meat, such as treating, decontaminating, irradiating, mixing, blending, grinding, and the like.
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In one embodiment, liquid carbon dioxide and liquid water are injected into port 358 at a pressure from about 200 psia to about 500 psia. The amount of liquid and carbon dioxide can be measured. Water can also be measured and introduced along with the carbon dioxide. Alternatively, the carbon dioxide and the water can be introduced at two distinct and separate injection ports. The amount of carbon dioxide can be based on the desired pH in vessel 312 or based on the pressure desired in vessel 312 or based on the quantity of water. Water can be any percent, such as 2%, of the mass flow rate of meat, plus any additional moisture that may be lost through evaporation. The water can additionally include salts, such as sodium chloride or sodium chlorite.
Carbon dioxide can be vented as a result of the drop in pressure in vessel 322. Carbon dioxide vents through port 302. The vented carbon dioxide may carry moisture. The decontaminated meat can be transferred out of the vessel 322 through port 306 and further processed in any desired manner.
In another embodiment, a rotating screw can be provided at the exit of vessel 312, at the union of the high pressure vessel 312 with the low pressure vessel 322. The rotating screw can be arranged to allow for decompression, and pressure reduction, gradually. To this end, the rotating screw can have gradually increasing volume between the flights of the screw.
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Meat is introduced into the high pressure vessel 312 through the injection port 360 by a variable speed pump (not shown). The meat is pumped at a pressure which can range from about 200 psia to about 850 psia. Instruments to measure level, flow, pressure, and temperature are located on all the appropriate conduits and vessels. In this manner, the amount of liquid or gaseous carbon dioxide and/or alternatively, the amount of water, can be controlled at a measured quantity based on the measured quantity of meat. The meat can be transferred in a continuous rate which may be adjusted as required by the variable speed pump, and the amount of carbon dioxide and water can be adjusted continuously and at a rate that corresponds and/or is proportionally related to the rate of the meat.
The retention time within the processing vessel 312 can be adjusted by the variable speed motor that drives the transfer screw within vessel 312 to ensure that the desirable number of microorganisms is destroyed. This number may exceed 5 log. The process can be capable of destroying at least a number of microorganisms equal to 10 to the log 5 (105). The process can also meet HACCP minimum standards.
Carbonic acid is the acid that is generated by the combination of carbon dioxide and water. However, under standard temperature and pressure conditions, the resultant acidic solution is only mildly acidic, having a pH of about 6. In one embodiment, the pressure in the high pressure vessel 312 can be about 500 psia and the temperature can be about 0° C. At this temperature and pressure, the pH of the liquid is about 3 to about 4. The pH can be controlled by adjusting the pressure in the high pressure vessel 312. For example, pressure can range from about 200 psia to about 850 psia, or greater than 850 psia.
The carbon dioxide can decontaminate and chill the meat and then evaporate leaving no residue other than water in vessel 322.
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With reference to the cylinder 614 with piston 624, meat can be injected via conduit 636. Meat can be pumped until cylinder 614 is filled, and piston 624 is fully retracted in hydraulic cylinder 620. Valve 630 is closed during filling. With respect to cylinder 610, and piston 626, meat has already filled cylinder 610. However, valve 628 remains closed. Piston 626 is in the fully retracted position. Cylinder 612 with piston 622 has valve 632 in an open condition allowing meat that has been processed with carbonic acid at high pressure and retained for an effective period of time, to be transferred out of cylinder 612 by movement of piston 622. The three cylinder and piston assemblies can be operated sequentially wherein one cylinder can be filled with meat, one cylinder can be in the process of being filled, and one cylinder can be in the process of being emptied.
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Conduit 1414 connects vessel 1354 with vessel 1408. A grinding plate 1402 can be mounted in conduit 1414. Alternatively, the grinding plate can be omitted. A conduit 1406 is connected to conduit 1414 so that goods, such as LFTB, can be introduced. Vessel 1408 is connected to conduit 1308. An insulated screw 1454 is mounted within conduit 1308 to transfer goods through conduit 1308, and which can also elevate the pressure to about 1050 psia. The vessel 1308 can be operated at a pressure from about 500 psia to about 1050 psia. The transfer screw 1454 can additionally be configured to induce mixing of the goods and can be attached to an electrical power source 1442. The transfer screw 1454 can be arranged with insulation 1438 so that power source 1442 can be attached to a collar 1444 in such a way that electrical current will flow through the transfer screw 1454 which is in direct contact with goods. In this way, an electrical current of variable and selected voltage can be passed through the goods, as the goods are transferred through conduit 1308. The vessel 1308 includes a gradually narrowing perforated section 1318 that leads to a conduit 1334 having a reduced diameter. Conduit 1334 can have one or more grinding heads 1306 provided therein. The conduit 1334 opens into the vessel 1302 via valve 1314. The perforated section 1318 is located downstream of transfer screw 1454, so that goods being transferred are compressed while passing through the perforated section 1318. The perforated section 1318 is surrounded by annular spaces 1328 and 1456 enclosed within conduit's 1308 exterior walls, which in turn are connected to conduits 1344 and 1346. Conduits 1344 and 1346 leading from the annular spaces are arranged to allow gases and liquids to be extracted from the meat, prior to grinding. These extracted gases and liquids can be subsequently recycled after conditioning in vessel 1432, where liquids may be removed from the gas via conduit 1340. The gas can be compressed to a suitable pressure by compressor 1436. Gas compressed by compressor 1436 can be transferred via conduit 1352 and can be recycled by injection into either of vessels 1354 and 1308 at ports 1462 and 1460, respectively, or at any other suitable port. Meat that is transferred along conduit 1308 can be compressed before grinding and then transferred along conduit section 1350 after grinding. The pressure at conduit section 1350 can be about 50 psi less than the pressure at conduit section 1334. An inlet port 1316 is provided along conduit section 1350, so as to allow the injection of goods, such as LFTB (Lean Fine Textured Beef) therein, at a suitable and controlled rate. The meat, which may include LFTB, is transferred into vessel 1302 after passing through valve 1314 and around valve plug 1332. The pressure in conduit 1334 at the location immediately upstream of grinders 1306 is affected by the rate of flow through grinders 1306. The pressure at section 1350 immediately downstream of grinders 1306, is controlled by the valve 1314. Valve 1314 can enable the complete closing at the exit end of conduit 1350. Valve 1314 is rigidly attached to rod 1328 that can provide opening and closing forces. The opening and closing force applied to rod 1328 is sufficient to completely close the valve thereby preventing any goods from passing through. In this way, the pressure drop that occurs when the goods are transferred into vessel 1302 will occur at the end of conduit 1350 immediately prior to transfer through the valve 1314, thereby allowing any chilling or freezing caused by the rapid decompression of carbon dioxide to occur at the point of exit. Screw 1322 mounted in the lower interior section of vessel 1302, is arranged to extract meat from vessel 1302. Recycled gas from compressor 1436 can be transferred for repeated use by combining with water and other selected substances, and injected into vessel 1408 via port 1460. The water added to the meat can be directly proportional to the quantity of meat. The amount of water can include the moisture loss that will occur as a result of processing the meat, after harvesting from the animal, and prior to packaging. The quantity of water added may also be controlled so as not to exceed any allowed amount, such as directed by the USDA (in the USA) or any other responsible Federal or State Government body.
The vessel 1302 is operated at a lower pressure as compared with the vessel 1308. The vessel 1302 is operated at a pressure from about ambient pressure or about 14.7 psia to about 20 psia or alternatively the pressure can be any pressure that is lower than the pressure in vessel 1308. The vessel 1302 has a conduit 1300, located at an upper location to exhaust any evolved gas or entrained moisture, from vessel 1302.
Liquid or gas carbon dioxide, and water at a pressure from about 200 psia to about 500 psia can be injected into vessel 1354 through port 1356. Carbon dioxide and water can be measured. The amount of carbon dioxide can be based on the pH desired in the vessel, or on the pressure desired so as to induce such desired pH, or based on the quantity of water or meat. The water can include the water that is anticipated will be lost through evaporation or otherwise. The vessel 1308 receives the liquid carbon dioxide, the liquid water, and the meat from vessel 1354 and 1408. Sodium chloride solution or any other suitable substance can be provided in vessel 1408 via conduit 1446, and in such quantities that will assist in lowering the pH of the carbon dioxide and water to about 1 to about 2. Screw 1454 causes the goods to blend and mix with the carbon dioxide, water and salt solution at a pressure of about 1050 psia. The goods are carried forward and at a speed that will provide adequate retention time within the vessel 1308 to ensure adequate killing of microorganisms, including pathogens or bacteria that reside on the goods. The sodium chloride or other salt compounds can be washed with water or other suitable washing agent after processing.
The goods can be ground by grinders 106. One embodiment of the apparatus includes one or more meat grinders 1306 disposed between vessel 1308 and vessel 1302. If more than one grinder is used, a coarse grinder can be followed by a fine grinder.
Following grinding, the contents of the vessel 1308, including meat, carbon dioxide, water, and salt, are emptied into the vessel 1302, that operates at a lower pressure relative to vessel 1308. The pressure in vessel 1302 can range from about atmospheric pressure (14.7 psia) to slightly below the pressure of vessel 1308. Carbon dioxide is vented through port 1300 from the vessel 1302. The vented carbon dioxide may carry moisture that can be compensated for with the addition of water. The meat can be transferred out of the vessel 1302 and further processed in any desired manner.
In another embodiment, a screw can be provided in conduit 1334 that allows for the gradual depressurization by increasing volume as meat travels down the screw.
The pressure and temperature in vessel 1354 are about 500 psia and about 10° C. At this temperature and pressure, the pH is about 3 to about 4. The pH can kill microorganisms, including bacteria and pathogens, and can also cause acid resistant organisms, such as some strains of E. Coli 0157:H7, to be weakened in the normal homeostasis process. After an effective residence period in vessel 1354, the meat can be transferred via conduit 1414 and vessel 1408 into vessel 1308. Sodium chloride or sodium chlorite solution added to the carbonic acid solution can cause the lowering of the pH in conduit 1308 to about 1 to about 2. Organisms that have been subjected to the conditions in vessel 1354 are then exposed to a lower pH in vessel 1308. Under these conditions, organisms that may have survived the energy exhausting conditions in vessel 1354 will not be able to survive the higher acidic conditions in vessel 1308. The pH can be controlled by adjusting the pressure of the vessels 1354 and 1308 and adding other pH adjusting substances. For example, some embodiments can use a pressure as low as about 200 psia, alternatively, some embodiments may use a pressure of greater than about 500 psia or some embodiments can use any pressure ranging from about 200 psia to about 1050 psia. Additionally, by passing an electrical current through the goods in conduit 1308, the organisms will be subjected to conditions that will inhibit their capability to maintain an internal pH.
One advantage of the methods described herein is that carbon dioxide can be used both to decontaminate and chill the meat, and afterwards, the carbon dioxide can evaporate leaving no residue other than water and in some cases a small amount of residual salt. The water added that is injected into the vessels 1354 and 1308 can be calculated and controlled, so that at the end of processing, the meat will have an allowable amount of water that can be the natural proportion of water, as determined by the standards or otherwise.
Conduit 1362 of vessel 1354 allows the transfer of meat under high pressure, such as about 500 psia. Conduit 1356 is arranged to allow the injection of carbon dioxide and water. A compressor 1390 is connected to an inlet conduit 1370, an outlet conduit 1396 and a pressure release conduit 1392. The pressure release conduit 1392 is fitted with a pressure release valve 1394, which allows the escape of gas when the gas exceeds a pre-selected pressure set point that will cause venting of gas. Alternatively, carbon dioxide gas can be recycled after release into conduit 1392. Carbon dioxide gas compressor 1392 extracts carbon dioxide gas via port 1422 from vessel 1354. After compression, the carbon dioxide gas is then re-circulated into vessel 1354, via conduit 1396 through ports 1400, and 1398 at the base of the vertically disposed vessel 1354. Meat is injected into the pressure vessel via conduit 1362 at a selected mass flow rate. Carbon dioxide and water is injected via conduit 1356 at selected flow rates. The meat will become exposed and blend with the water and carbon dioxide in vessel 1354 through the use of agitator 1412. The meat will substantially fill vessel 1354 to a predetermined level before gate valve 1388 is opened. Carbon dioxide will be lighter than the meat and water contained within vessel 1354 and will therefore tend to accumulate at the upper end of vessel 1354. Port 1422 is located and arranged to allow extraction of the carbon dioxide gas via conduit 1370. Compressor 1390 can elevate the pressure by about 25 psi to about 50 psi and then recycle the compressed gas via conduit 1396, and conduits 1348 and 1400. The carbon dioxide gas will reticulate upwardly and blend with the meat within pressure vessel 1354. The meat is agitated by apparatus 1412. The carbon dioxide gas will mix with the water contained within vessel 1354, forming acidic carbonic acid. The carbonic acid will destroy or weaken pathogens that may be present at the surface of the meat. After an effective period, the meat can be extracted from pressure vessel 1354 via conduit 1414, and transferred into vessel 1408 at a selected rate about equal to the rate of meat that is injected into vessel 1354. The method of transfer from the relatively lower pressure vessel 1408 to the higher pressure in conduit 1308, is by way of a rotating screw 1454. The transfer mechanism can both transfer the meat and also elevate the pressure of the contents within conduit 1308. If so desired, LFTB having been processed according to the process described in association with
Conduit 1380 with valve 1372 is shown at the upper end of pressure vessel 1354. Valve 1372 can selectively allow injection of any liquid or gas, such as carbon dioxide at an elevated pressure, into vessel 1354 when valve 1372 is switched to an open position. Conduits 1362 and 1356 are shown with valves 1374 and 1376. Conduits 1398 and 1400 are shown with valves 1382 and 1384, and conduit 1370 is shown with valve 1468. Additionally, conduit 1406 is shown with valve 1386, and a gate valve 1388 is shown in conduit 1414, wherein the valve 1468 is interposed between vessel 1354 and vessel 1408. The purpose of valves 1376, 1374, 1372, 1468, 1382, and 1384, and gate valve 1388, is to isolate vessel 1354 so as to be able to retain the meat within vessel 135 for an effective period. The meat, water, and carbon dioxide are injected into vessel 1354 via conduits 1362 and 1356 at a pressure of not more than 500 psia after closing gate valve 1388 and valves 1382, 1382, 1383, and 1468. After substantially filling vessel 1354 with meat, water, and carbon dioxide, valves 1376 and 1374, and 1372 can be closed. In this condition, the pressure inside vessel 1354, is approximately 500 psia. Valve 1372 remains ready to open so that high pressure carbon dioxide gas and/or liquid carbon dioxide can be transferred into vessel 1354. Carbon dioxide gas transferred through conduit 1380 will be at such pressure and volume so as to elevate the pressure within vessel 1354, to a pressure substantially higher than 500 psia, such as about 850 psia or even as high as about 1050 psia or more. By doing this, the pH of the carbon dioxide and water (carbonic acid), will decrease in a short amount of time to a level of about 2 to about 3 pH. The increase in pressure can be produced suddenly to produce a sudden and substantial pH reduction. When sodium chloride or other pH adjusting substance is present, the pH may be as low as about 1 to about 2. A sudden lowering of the pH of the liquid in contact with the meat can cause a rapid death of pathogens, and decontamination of the meat. Other pathogens such as salmonella can also be killed in this manner. By processing meat with the multiple stage methods disclosed herein in association with
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The carousel assembly shown in
Conveyor 1708 can be enclosed in a tunnel that is flooded with chilled filtered air, at a positive pressure, and wherein the enclosed tunnel connects directly to a temperature controlled packing room, where processed and decontaminated goods can be packed after decontamination, and in such a manner that other potential vectors of recontamination are minimized.
For the decontamination of plant material, wherein the plant material contains stomata; microorganisms, including bacteria, can inhabit the interior of the plant material by gaining access through these stomata. The stomata can close, thereby trapping the microorganisms in a location where it is difficult for decontamination agents to treat these microorganisms. Therefore, for decontaminating plant material, it is desirable to cause the stomata to open, thus allowing the decontamination agent, including carbonic acid, made from carbon dioxide and water at high pressure, to reach the microorganisms contained within the stomata of plants. The stomata can be opened prior to the treatment with the decontamination agent. Certain applications where this may be of use are in the decontamination of cabbage and broccoli, for example.
In certain instances, the processes disclosed herein can be used to fully pasteurize and eliminate the presence of pathogens from goods, such as meat. In these instances, the processed goods can be inoculated, after elimination of the harmful pathogens, with generic or spoilage bacteria that are not harmful to humans.
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The processes disclosed herein can provide an effective means for decontaminating meat, including boneless beef, by firstly exposing the meat to a very high pH anywhere in the range from about 12 to about 14 for a selected or effective period of time followed by exposure to a low pH anywhere in the range from about 1 to about 3 for a further selected or effective period of time. Such a process can be capable of killing microorganisms, and decontaminating or pasteurizing the meat while also maintaining the meat at a low temperature of about 40 degrees F. Additionally, carbon dioxide and water can be provided in amounts and under conditions described herein, to control the water content and fat content in meat.
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Once an alkali metal chlorite has been applied, the meat containing the alkali metal chlorite is transferred to a pressure vessel, represented by block 2002. The pressure vessel can have an inlet and an outlet, and means to transfer the meat from the inlet to the outlet. Transfer apparatus may include conveyors, belts, and the like. However, meat can transfer through a vessel utilizing the force of gravity. The pressure vessel can be fitted with instrumentation to monitor the amount of meat passing the inlet and the outlet. The pressure vessel may also be fitted with fat and water measuring devices at all inlets and outlets that can measure the fat and lean content, and water, of the meat. The pressure vessel may also be fitted with any other suitable instrumentation to monitor the pressure and/or temperature and the liquid level in the pressure vessel. The pressure vessel may have any number of additional inlets for the addition of agents, including alkali metal chlorites, carbon dioxide, and water. Every inlet can be fitted with a measuring instrument to measure the amount of agent passing through the inlet. Every inlet can be fitted with a metering device, such as a control valve, to accurately meter the amount of agent passing into the pressure vessel.
Carbon dioxide can be added in sufficient quantities so that the carbon dioxide together with the alkali metal chlorite and a water phase present in or on the meat produce a carbonic acid/alkali metal chlorite solution of sufficiently low pH to cause inactivation of microorganisms. The carbon dioxide addition can occur after the alkali metal chlorite addition in order to prevent reaction between the alkali metal chlorite and the acid prior to their exposure to the meat. In this manner, the chlorite is conserved and used when present on the meat. The pressure vessel of block 2002 is pressure controlled within any of the pressure and temperature ranges described herein. Carbon dioxide addition may take place as a solid, a liquid, a gas, or as a supercritical fluid. The carbon dioxide is added in an amount that is effective to cause the desired lowering of the pH to within the ranges described herein effective to inactivate microorganisms, such as bacteria.
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In addition to alkali metal chlorite agents, any other suitable agent, such as sodium chloride, may also be added before, during, or after any of blocks 2000, 2002, 2004, and 2006.
The use of a “multiple hurdle” strategy for pathogen decontamination of goods, such as meat, is provided. According to the invention, each decontaminating hurdle may have a limited, but nevertheless unsubstantial deleterious effect on the quality of the food, and it is therefore desirable to minimize the intensity of each treatment. Multiple hurdle is a strategy with a series of multiple treatments of minimized intensity, thereby minimizing the overall combined deleterious effect, as compared to a single more aggressive treatment. For example, irradiation that pasteurizes the meat in a single treatment is more deleterious to the meat when compared to multiple, albeit, lesser intense treatments. Such a single treatment with irradiation, in the presence of air, would cause oxidation or rancidity that can otherwise be reduced with multiple treatments. Additionally, a multiple hurdle strategy may create virulent strains of a pathogen, not by “natural selection” but by “multiple hurdle selection”. According to the invention, each hurdle is followed by a subsequent treatment within an effective period of time that does not allow the pathogens to adapt to an enhanced acid tolerance that would enable survival of the pathogen in a subsequent treatment.
The multiple hurdle processes herein disclosed provide for the decontamination of goods, such as meat, without substantial deleterious effect on the meat quality. The meat is packaged directly after decontaminating so as to reduce the possibility of recontamination. The processes also enable reproducibility, according to HACCP standards, using agents, such as “processing aids” as defined and allowed by USDA. The USDA definition of “processing aids” are those specified agents, used according to a HACCP method in a specified process, in a USDA acceptable decontamination process and wherein USDA allows the use of agent(s) without the requirement to disclose the use or presence of the agent(s) in the essential information shown on a label affixed to the finished and packaged meat product.
Sodium ions, naturally present in meat, such as in lean beef that contains about 0.1% sodium chloride, can assist in lowering the pH of the carbonic acid. Additionally, the natural acid “buffering effect” of meat can be minimized by adding an overwhelming amount of pressurized carbon dioxide, combined with any added sodium compound(s), including sodium chlorite. These conditions can cause production of a low pH acid at the meat surfaces, which is lethal to pathogens when the pathogens remain in this environment for an effective period of time. Mass-flow control of meat through the pressure vessel, in combination with control of carbon dioxide density and pressure, sodium ions, and water, within the vessel, enables the control of pathogens present at the meat surfaces. The exposure period is related to the residence time within the treatment vessel, which is determined by adjusting the mass flow rate of meat through the vessel. The low pH condition, can be enabled upon positive displacement pumping creating the desired high pressure and the very low pH condition can be terminated by pressure reduction upon extraction of the meat from the treatment vessel and into a controlled lower pressure vessel. Such pH control enables use of an acid shock treatment (AST) that is highly lethal to pathogens, while the deleterious effects to the meat, that over exposure to a pH of about 2 would otherwise cause, are substantially limited. This continuous decontamination process can be used to treat meat in combination with other suitable bactericidal treatments, such as irradiation.
The system according to the invention can measure the mass flow of the meat and proportionately add water and carbon dioxide. The amount of added water can be adjusted to compensate for moisture losses due to dehydration, and/or to ensure product labeling is not required.
In another embodiment, meat or vegetables, can be treated with ethanol and/or lactate prior to exposure to carbonic acid. The ethanol and/or lactate can be applied to the food, in a manner that will ensure exposure of substantially all surfaces to the ethanol/lactate, prior to transfer into a pressure vessel containing carbon dioxide and water, and at a pressure of about 550 psig or greater, and at a temperature of about 40° F. Under such conditions, carbonic acid can have a pH of about 2 to about 3. The combination of ethanol and/or lactate with carbonic acid creates an environment lethal to pathogens, including any acid-adapted Escherichia-coli 0157:H7. When E. coli is exposed to an ethanol, of about 5%, and lactate combination at a pH of about 3, the collapse of the cytoplasmic pH can occur suggesting that cell membrane permeability to protons is compromised and/or the capacity to pump protons out of the cell is reduced, causing death to the bacteria. The conditions when goods, such as meat, are exposed to liquid and/or dense vapor carbon dioxide, can be comparable. The high solvent property of liquid carbon dioxide can be a perturbant (similar to that of ethanol) to the cell membrane and the pH of carbonic acid (formed by combination of carbon dioxide and water) at about 36 degrees F., and 600 psig is about 3. Therefore, when the goods are exposed to liquid carbon dioxide and/or very dense carbon dioxide vapor, the population of E. coli (and other bacteria) can be reduced by about 4 log, in about 5 minutes of exposure.
The density of the pressurized carbon dioxide can be at least about equal to or higher than about 20 lbs/cubic foot, such that when the meat and dense carbon dioxide are in contact and located together in a treatment pressure vessel and agitated, the carbon dioxide will assist in opening and separating any flaps, slits, cracks and/or leaves that may be enclosing pathogens in a location protected from exposure to the lethal agent or combination of agents intended to kill the pathogens. Following treatment with carbonic acid, as disclosed, the meat can be exposed to a low dosage irradiation source such as e-beam, or x-ray of sufficient intensity to kill substantially all remaining weakened pathogens.
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After grinding, the meat can be further treated by exposure to irradiation, including any e-beam treatment, while still being retained within a conduit substantially excluding oxygen of less than 5% by volume, or less than 3% by volume or less than 1% by volume or less than 300 ppm by volume.
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The process of e-beam irradiation has been used to kill pathogens on goods after packaging, therefore requiring that the packaging be also subjected to the e-beam irradiation. This results in an inefficient use of the expensive irradiation process. Packaging materials can be kept clean and without contamination by other less expensive decontamination processes (such as with the application of heat or Ultra Violet C). Accordingly, by decontaminating the goods and packaging materials separately, prior to assembly of the goods and packaging, a substantially more efficient method of decontamination is achieved. Efficiency is further improved when acid shock treatment and a reduced but adequate application of e-beam irradiation are combined.
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The apparatus includes a first processing vessel 2312 having an entry port 2368 for the meat, and an entry port 2360 for carbon dioxide and water 2300. The vessel 2312 can be operated at a pressure ranging from about 500 psia to about 800 psia. The vessel 2312 includes a transfer screw (not shown) to transfer the goods from the entry port 2368 at one end of the vessel to the opposite end. The transfer screw can additionally be configured to mix the goods. The vessel 2312 includes a narrow section that leads to a conduit 2338 of reduced diameter. The conduit 2338 has one or more grinders 2310. The conduit 2338 leads into a second vessel 2304. The vessel 2304 is operated at a reduced pressure as compared with the first vessel 2312. The vessel 2304 is operated at a pressure from about ambient pressure or about 15 psia to about 20 psia or any pressure that is below the pressure in vessel 2312. The vessel 2304 has a conduit 2302 located at an upper portion to vent any evolved gas or entrained moisture from the second vessel 2304. The second vessel 2304 also has an exit port 2306 for the meat.
In one embodiment, liquid carbon dioxide and liquid water are injected into port 2360 at a pressure from about 200 psia to about 500 psia or greater. The carbon dioxide and water can be measured and metered into vessel 2312. The amount of carbon dioxide can be based on the pH in the vessel, or on the pressure in the vessel, or based on the quantity of water or meat.
The horizontal vessel 2312 includes a transfer screw that may rotate about a longitudinal axis. This screw is arranged to cause the meat to blend and mix with the carbon dioxide and water at a pressure of about 500 psia or greater. The screw operates at a speed which will provide adequate retention time within the vessel 2312 to kill any microorganisms, including pathogens or bacteria, which may reside on the meat.
An electron beam generator 2372 can be integrated so as to enable the irradiation of meat, as the meat is transferred along the horizontal conduit 2352 and before the goods are ground by grinder 2310.
A blend of gases, including carbon dioxide with a small quantity of carbon monoxide can be used. Carbon monoxide causes a red color in pork, beef and other meats. The resultant color is a vivid bright red and will remain bright red for several weeks and well beyond the point in time when other red meat, not exposed to carbon monoxide, but normally exposed to oxygen or ambient atmosphere will normally become discolored. This discoloration is undesirable and occurs as a result of gray-brown colored metmyoglobin forming at the surface of the meat. Red meat intended for human consumption may be exposed to any approved gas, such as carbon dioxide, having a carbon monoxide content less than 0.5%. Such a small amount of carbon monoxide would not normally be sufficient to cause the vivid red color staining, however, the effect of carbon monoxide is cumulative, such that when meat is exposed for an effective period to a blend of gases containing 0.5% carbon monoxide and 99.5% carbon dioxide, the cumulative effect can enable the generation of the vivid red color. This can be accomplished when a blend of gases comprising an amount of carbon dioxide about 99.5% of the combined gas blend and an amount of 0.5% carbon monoxide is compressed and used in the process described herein. Accordingly, such a blend of gases can be used at such selected pressure and temperature that will enable decontamination as desired and can also enable color enhancement of the red meat so as to minimize discoloration.
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Vessel 2464 includes an annular tube section 2490 attached to an upper cone 2526 and a lower cone 2500, at flanges 2516 and 2518, respectively. Any lean meat in the stream transferred into vessel 2464 will be transferred downwardly into cone 2500, and the fat component will be transferred upwardly into cone 2526, and ultimately through conduit 2480. Such fat can be considered a waste stream that can be transferred to a rendering plant. Lean meat is transferred through conduit 2502. Annular space 2484 in upper cone 2526 is in communication directly with port 2488, allowing fluid to be extracted therethrough. Similarly, annular space 2494, located at the lower end of the lower cone 2500, is attached to port 2498 in such a manner as to allow extraction of fluid. Fluid transferred with the fat stream into tube section 2490 can be extracted through ports 2488 and 2498 and via manifold 2478. Fluid extracted through ports 2442, 2448, 2488, 2498, and manifolds 2478 and 2434, can be connected to a common pipe 2468, that leads directly to a compressing pump 2466, with downstream pipe 2456. Fluid thereby collected and transferred through pipe 2456 can be filtered, adjusted in temperature, and then transferred and measured, into mixing chamber 2420. Lean meat transferred through conduits 2502 and 2452, are combined together in conduit 2506. This combined lean stream product can be incorporated in the production of ground meat.
Valves and pressure release valves can be provided on all ports and arranged to open and close in a manner allowing transfer of material therethrough at selected flow rates that can be automated and controlled by a computer.
Agents for use in the present invention may include any selected temperature and pressure controlled, liquefied or vaporized gas or a blend of liquefied or vaporized gases including carbon dioxide and/or any atmospheric gas(es), carbon monoxide, ammonia or any other suitable gas or processing aid including water or any agent(s) including sodium citrate, sodium chlorite, tri-sodium phosphate and/or sodium chloride or any combination thereof, that may be dissolved in water (or carried as a suspension therein), and that can be mixed with any liquefied or vaporized gas or gases.
Carbon dioxide, at a pressure above about 1,056 psig and at a temperature above about 87.82° F., is at the critical temperature and pressure. Carbon dioxide cannot exist as a liquid under these conditions. Below 1,056 psig and 87.82° F., carbon dioxide can exist as a liquid and a gas or a saturated vapor. The specific volume (density) of carbon dioxide at 1,056 psig is about 0.03453 ft3/lb (or 28.96 lbs per cubic foot). The maximum density of water occurs at 39.2° F. (4° C.) when 1 cubic foot weighs about 62.4 lbs. However, the density of carbon dioxide at 40° F. is about 55.99 lbs per cubic foot. Therefore, liquid carbon dioxide can float on water at 40° F. when the water is saturated with dissolved carbon dioxide. A temperature of about 109° F. is the maximum temperature of a beef carcass following death. Fresh beef will freeze, at least partially, when its temperature is reduced to below about 28.5° F. At about 26° F. or below, fresh meat will freeze. It is therefore desirable that the processing temperature range for meat is maintained at above about 28.5° F. and below about 109° F. The density of carbon dioxide at 28° F. is about 58.58 lbs/cubic foot. The density of fat is slightly lower than the density of water and the density of lean meat is slightly more than the density of water. In each case, the density of fat and beef will vary according to its water/moisture content.
One aspect of the invention provides a method to produce processed meats having a water content that can be controlled to within any limits. When exposed to ambient, dry, or refrigerated air, fresh beef will undergo dehydration at a rate of about 1% per 24-hour period. The dehydration rate can be used to calculate and meter water used as a processing aid to compensate for the water loss or to adjust the water content of meat to any selected level. As indicated in a Draft Directive recently issued by the FSIS division of the USDA, it is understood that USDA intends to impose new regulations that will allow compensation for loss of moisture due to such dehydration by addition of an amount of water, derived only from water contained in an agent as a processing aid of said agent. The natural, original weight of meat harvested from a freshly killed carcass, cannot be exceeded by 0.5% of its natural weight, and that any added water must be less than 0.5% of the original, natural weight of the beef.
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The processes disclosed herein will provide accurate temperature control of the agents, including the meat being processed, to below about 109° F. and above about 28.5° F. The pressure of any agent that comprises carbon dioxide, or a combination of agents including carbon dioxide, will be maintained within reasonable and safe limits, including not more than about 2000 psig. The amount of added water that remains with the meat, after processing can be controlled at any level.
Carbon dioxide can be useful for adjusting the fat content of a stream (or batch) of boneless meat. When carbon dioxide is held at a temperature and pressure above the critical point, the supercritical carbon dioxide fluid can act as a solvent that can remove fat from lean meat. When meat is exposed to carbon dioxide at or above the critical point, fat can be separated from lean meat by measuring the fat content (and the moisture content) of the meat prior to treatment, followed by treatment with accurately measured and controlled quantities of carbon dioxide above the critical point and at a specified temperature and pressure for an effective time period, and also treated with water alone or together with a processing aid, so that a specified quantity of fat can be removed from the meat, and the moisture content can be raised to the level before dehydration. In this way, when meat is exposed to a controlled quantity of supercritical carbon dioxide for a selected period of time, a predictable amount of fat can be removed from the meat.
In one aspect of the invention, a method is provided for measuring and recording the natural weight of post mortem beef, that is harvested from carcasses prior to significant weight loss due to dehydration. The weight data can be used to establish a typical weight loss due to dehydration that can occur during a refrigeration process. The meat can be hydrated through a process of controlled hydration from “processing aid” water contained with any decontaminating agent.
In one aspect of the invention, a method is described for separating fat from lean meat, and for simultaneously decontaminating the meat by reducing the bacteria on the surfaces of the meat with the carbon dioxide used to separate the fat.
In one aspect of the invention, a method is described for adjusting the fat content of meat, according to a specified fat content requirement, prior to grinding the meat to produce ground meat with a fat content as desired and within a tolerance of about +/−0.25% of the desired fat content. According to the invention, it would not be necessary to cut any fat cover from the meat prior to processing with carbon dioxide, since the fat will dissolve in the carbon dioxide and be removed therewith. The method of the invention has many benefits over the existing system of ground chuck production, for example. Firstly, the method according to the invention requires less labor to harvest the boneless beef chuck primal from the carcass and secondly, the method results in less contamination. The need for the commonly practiced process of LFTB production from the discarded fat stream produced in all beef boning operations, is eliminated. The problems associated with cross contamination and bacterial growth are also eliminated.
Additionally, the meat can be processed by exposing its surfaces to carbon monoxide so as to enhance the color of the meat wherein the carbon monoxide can be blended with another gas, including carbon dioxide, in proportions of not more than about 0.5% carbon monoxide with the balance being substantially carbon dioxide. Carbon monoxide can also serve as a decontaminating agent by killing or injuring bacteria that may be present at the meat surfaces.
Referring again to
Ports 2644 and 2630 are arranged to communicate directly with the interior of conduit 2640 via annular connections 2646 and 2666, with annular spaces 2652 and 2636, respectively, which are connected via an annular slot or a series of slots 2650 and 2634, respectively. Ports 2664 and 2608 allow for the removal of agents and other materials extracted from the meat being processed in conduit 2640. Variable speed motor 2656 is mounted at an end of conduit 2640 and coupled directly to a shaft with paddles and screw fixtures 2642, 2626, and 2610. Processing conduit 2640 has a restriction 2638, which is a narrowing of the vessel 2640 diameter that can pressurize the meat being processed. Perforated section 2622 is provided and arranged to match screw profile 2626, in such a way that solids will be forced to follow conduit 2624, and liquids will pass through perforations into space 2628 and be exhausted through port 2664. Valves and pressure regulators are fitted on conduits to provide adjustments required for the processing of meat including the control of the residence time of the meat being processed in conduit 2640. The apparatus is controlled by a suitable PLC or computer, enabling automated operation according to any program developed and found to be suitable in the processing of the meat. The PLC or computer is arranged to control the mass flow rate of meat and any agents into conduit 2640, and extraction therefrom and also to control variable speed drive motor 2656. By adjusting the mass flow of meat and agents transferred into conduit 2640, the residence time and the effect of the agents on the meat being processed can be controlled accurately, and in a manner that will enable optimum production rates.
Conduit 2624 is connected to a second processing conduit 2666. A third agent inlet port 2614 is provided with connection to the annular space 2612 and annular slot 2620. Paddles and screws 2610 are arranged to mate with the perforated section 2606 so as to enable the extraction of liquids or gases from conduit 2660 in a manner similar to that described for conduit 2640. At this point, agents and meat can be divided into two streams, wherein the solid items are transferred along conduit 2604 and through moisture and fat measuring device 2602, and liquids and gases pass through perforations into space 2472 and then are exhausted through conduit 2608. With the above described apparatus, meat can be processed with agents that blend with the meat and are exhausted through conduits 2664 and 2608. Suitable agents may be liquids, solids, or gases or supercritical fluids, provided at any temperature and pressure for decontamination, separation, rehydration, or for any other purpose. The apparatus as described above can be used to process a range of food products, including meat, such as boneless beef, by exposure to carbon dioxide gas pressurized and heated to greater than about 1056 psig and above about 88° F. Such carbon dioxide can be provided through ports 2644, 2630, and 2614 at a pressure of about 1100 psig and at a temperature of about 90° F., and transferred into the processing conduits 2640 and 2666 to mix with the meat provided therein at a temperature of about 35° F. to about 40° F. The carbon dioxide, under these conditions, will enable the removal of fat from the meat, which can then be removed with the processing gas or liquid through conduits 2664 and 2608. The meat, which will then comprise lean meat having reduced quantities of fat, can be transferred through conduit 2624, into conduit 2666. As it is transferred through conduit 2624, the fat and moisture content can be measured by the measuring device 2670 prior to entry into conduit 2666. Based upon the measured fat and moisture content, additional carbon dioxide with a measured quantity of water can be transferred into conduit 2666 via port 2614 to further adjust the moisture and fat content of meat. Additionally, carbon dioxide can dissolve in water to produce carbonic acid of low pH that will cause inactivation of microorganisms, such as pathogens. Additional agents may be added to further decrease the pH. Agents, including sodium chloride, sodium chlorite, and any other salt, can be used. Carbon monoxide, water and buffered sodium citrate or sodium chloride may be added to carbon dioxide, for example. Carbon dioxide and water can be adjusted in pressure and temperature according to the measured amount of fat and moisture of the meat. Moisture can be added and fat removed through the process to produce a finished decontaminated product of desired fat and water, and thereafter measured to confirm the accuracy of the process.
The embodiment of the apparatus shown in
In one aspect of the invention, the beef exiting conduit 2602 may further be decontaminated using x-ray or electron beam (e-beam). A series of these partially effective decontaminating steps when put together can combine for complete decontamination. Multiple hurdle decontamination may avoid damaging the meat as compared to any single-step decontamination technique. A series of mild decontaminating steps are as effective as a single, strong application of any decontaminating technique without having the detrimental effect of possibly damaging the meat.
The process provides simultaneous extraction of measured quantities of fat from a mass flow controlled stream of meat, enclosed in a sealed, pressurized, heated, and temperature controlled conduit to enable production of decontaminated meat having a selected fat and water content.
A sanitizing agent, including ozone, can be used to disinfect the apparatus without the need to open the vessel. To this end, the apparatus can be constructed without sharp corners to eliminate dead areas where meat may remain stagnant. The apparatus can be used with a clean-in-place system that does not require the apparatus to be opened for cleaning and sanitizing. Cleaning may be conducted with any suitable agent, such as steam or ozone.
Referring now to
Referring now to
Carbon dioxide is stored in vessel 2706. Conduit 2710 allows vessel 2706 to be filled with carbon dioxide from an exterior source. Conduit 2715 allows carbon dioxide gas to be transferred into pressure vessel 2626. Vessel 2722 is arranged with a heater to raise the temperature of carbon dioxide transferred along conduit 2624, to ensure that carbon dioxide delivered to conduit 2640 is at supercritical temperature and pressure. An additional carbon dioxide storage vessel 2720 is replenished by an outside source transferred from conduit 2632. Compressors 2716 and 2682 recycle carbon dioxide extracted from equipment 2658 and 2678, and transfer the carbon dioxide into vessels 2714 and 2720, in readiness for subsequent use. Conduit 2676 allows the transfer of carbon dioxide into continuous blender 2678. A supply of carbon dioxide gas is transferred along conduit 2620, into pumping vessels 2616, 2634, and 2636. A supply of carbon dioxide is supplied into equipment 2658 along conduit 2652. Pumping vessels 2616, 2634, 2636, and 2724, can be any suitable pump, such as meat pumps manufactured by Marlen.
Referring now to
Referring now to
Boneless meat is loaded into vessel 2902. The meat may be chilled prior to loading therein, to a temperature in the range of about 28° to about 45° F., but most preferably to a temperature of about 35° F.±1%. The apparatus is arranged to perform several functions that include the extraction of a measured quantity of fat from the meat that is transferred to vessel 2902. The processed meat can be transferred to a continuous blender, wherein the continuous blender may be arranged with a supply of two or more streams of meat.
The equipment is arranged to periodically and automatically test for and determine the presence of bacteria. Samples for testing can be extracted via extraction port 2968. The sample that is extracted may be a fluid that has accumulated at the base of vessel 2902. The fluid so removed can contain bacteria from the meat, and can be representative of the population of bacteria present within the meat. The extraction point will be arranged such that the fluid that is extracted is representative of the meat. The sample extracted can be automatically tested. The automatic testing apparatus, which is not shown in
The process disclosed herein furthermore includes a method to decontaminate the meat of microorganisms, such as bacteria. A concentrated solution of sodium chlorite is injected into conduit 2964 in an amount that can be automatically adjusted, by, for example, the quantity of fat removed from the meat and the water content of the meat. The sodium chlorite solution is injected via port 2966. Vessel 2902 is connected directly to a meat pump capable of pumping at variable speeds to vary the meat flow rate through conduit 2964, and the pressure can also be controlled. A series of fat, water, and protein measuring devices, are shown as items 2904, 2948, 2944, 2924, 2936, and 2960. The measuring devices are integrated into the conduits to enable the automatic measuring of the meat properties, including, but not exclusively, flow rate, weight, water content, fat content, and lean meat content. Vessel 2906 is connected through measuring device 2948 and conduit 2966 to vessel 2946. Vessel 2946 is connected to vessel 2922 via conduit 2916. GMS measuring device 2944 is located on conduit 2916. Vessel 2922 is connected via conduit 2962 and measuring device 2924, to vessel 2958. Vessel 2958 is connected via conduit 2934 to pumping vessel 2928, which in turn transfers meat through measuring device 2960 and conduit 2932.
The meat pumped into vessel 2906 is blended with sodium chlorite solution injected via port 2966. Vessel 2906 is fitted with impellers that both mix the sodium chlorite solution and meat together, while transferring the meat stream into pump 2950. Carbon dioxide and water can be added to vessel 2906 via port 2954 at a selected pressure and temperature. The pressure maintained in vessel 2906 can be greater than or about 500 psig to about 850 psig. As the meat is transferred into vessel 2906, the water content, fat content, and lean meat content are measured by measuring device 2966. Pump 2950 transfers the meat and increases its pressure to about 1100 psig to about 2000 psig. The temperature at the surfaces of the boneless meat is elevated to greater than about 90° F. as it is transferred through vessel 2906. Heating can be by way of a steam jacket installed around vessel 2906, for example. The temperature of the meat can be maintained above about 90° F. and below about 109° F. Meat pumped by pump 2950 is transferred through measuring device 2948, and the mass flow and pressure are controlled as required by a mass flow regulator installed in conduit 2966. The heated meat is blended with the sodium chlorite solution in a manner that substantially ensures that the sodium chlorite solution thoroughly covers all surfaces of the meat and is forced into crevices, slits, cuts, and cracks in the meat and fat, in sufficient quantities. The meat transferred directly into pressure vessel 2946, is blended with a measured supply of supercritical carbon dioxide injected via port 2910. The blend of meat, sodium chlorite solution, and supercritical carbon dioxide, is continuously blended in pressure vessel 2946. The supercritical carbon dioxide can cause a rapid lowering of the pH on contact with the sodium chlorite solution at the surfaces of the meat. The pH can be about 2 to about 3. Under these conditions, carbonic acid, hypochlorous acid, and hydrochloric acid are produced at the meat surfaces. The combination of acids is lethal to pathogens, including E. coli 0157:H7, salmonella, and other pathogens. In addition to substantially killing the majority of the pathogens and bacteria, the supercritical carbon dioxide will dissolve fat. Supercritical carbon dioxide is an effective solvent and will dissolve fats at a predictable rate. The flow of supercritical carbon dioxide through port 2910 is controlled according to the fat content and water content of the meat. The dissolved fat with other contaminants therein, and a major portion of the sodium chlorite solution, are extracted via conduit 2914. Vessel 2946 can be arranged in a manner that enables the separation of the combined stream of materials flowing through vessel 2946, into two streams, wherein the first stream includes dissolved fat and is directed through port 2914, and a second stream includes meat that is transferred through mass flow regulator fitted in conduit 2916, and through measuring device 2948. The fat, water, and lean meat content of the meat stream are measured with measuring device 2948, before exposure to supercritical carbon dioxide in vessel 2946, and then again with measuring device 2944, after treatment in vessel 2946. The difference in fat, water, and lean meat content can be calculated. The information can be used to control the mass flow and pressure of the carbon dioxide and water provided to pressure vessel 2946. Most particularly, the fat and water content of the meat can be adjusted while substantially killing and removing surface pathogens and other contaminants. The treated meat is transferred through measuring device 2944 into vessel 2922, wherein a pressure drop from the specified gas pressure within vessel 2946 occurs. The pressure can drop from the higher level of about 1100 psig to about 2000 psig, to a lower pressure of about 500 psig to about 750 psig. Such a pressure drop will cause a rapid reduction in the meat surface temperature and pH. Vessel 2922 is therefore controlled at an internal pressure of about 500 psig to about 750 psig. The temperature of the meat can also be adjusted within vessel 2922 by injection of liquid or dense carbon dioxide gas via port 2940, and carbon dioxide gas can be extracted and recycled, via conduit 2920. If so desired, a pathogen and/or bacteria detection system, as described hereinabove, may be installed between vessel 2922 and vessel 2958. The treated meat is regulated from vessel 2922 through conduit 2962. The meat is then transferred through measuring device 2924 and into vessel 2958, which is substantially similar to vessel 2922, having port 2938 for the addition of carbon dioxide. Gas is extracted from vessel 2958 via port 2956. The temperature and pressure of the meat are measured at selected points. Adjustments can be automated and executed by a computer. Data or measurements can be recorded and associated with the meat as it is transferred through the vessels so that the meat from different animals remains associated with the data pertaining to the animal and tracked throughout the process. The method for identification of the meat with an animal is enabled by controlling mass flow, and with volumetric measurement, the location of any identifiable portion of meat can be tracked to the animal. The data collected can be recorded in a database, wherein said database is accessible by multiple users. The meat's properties, including its origin, age, and all other properties, can be associated with any package containing the meat and a label containing any information can be attached to the package.
The meat is then transferred from vessel 2958, through conduit 2972, through measuring device 2936, followed by transfer through conduit 2934, and into vessel 2928. A pump enables pumping of the treated meat through measuring device 2960, and into conduit 2932. Conduit 2932 can be attached directly to an enclosed storage vessel (not shown), which is temperature controlled, and filled with a selected gas, enabling storage of the processed meat in readiness for subsequent processing or packaging.
A pressure drop between vessel 2922 and vessel 2958, can occur to lower the pressure in the range of about 50 psig to about atmospheric pressure. Such lowering of pressure will result in a temperature drop. Port 2938, for example, may provide a gas, such as carbon dioxide, at a temperature that enables adjustment of the temperature of the meat. Such temperature adjustment may require elevation or reduction according to the original temperature of the boneless meat provided into vessel 2902.
The sodium chlorite solution applied to the surfaces of boneless meat in vessel 2902 may be applied, in concentrations from 500 ppm to 1200 ppm according to USDA regulation 21 C.F.R. § 173.325. However, given the effective removal of a substantial proportion of the added sodium chlorite solution with the liquefied fat extracted from vessel 2946, it is anticipated that higher concentrations of the sodium chlorite solution may be used. For example, a concentration above 1,200 ppm, such as about 2,500 ppm to about 3,000 ppm and above, should be possible according to the invention.
The increased quantities of sodium chlorite will enable application of increased quantities of water, resulting in significantly improved antimicrobial effects.
In one embodiment of the invention, after application of a sodium chlorite solution of concentration from 500 ppm to 1200 ppm in accordance with USDA regulation 21 C.F.R. § 173.325 in vessels 2902 and 2906, the removal of substantially all sodium chlorite solution (including excess water) during processing in vessel 2946 is possible. Therefore, a second application of sodium chlorite solution, at a selected and automatically adjusted concentration, can be injected at a controlled mass flow rate via port 2940 in vessel 2922. Carbon dioxide gas at about 550 psig and water can be introduced via another port, such as a bottom port in the lower sections of vessel 2922. The carbon dioxide addition can be combined with a heating system to elevate the temperature of carbon dioxide to a temperature of about 90° F. to about 109° F. Carbonic acid is produced having a pH of about 2 to about 3. The treatment according to the invention ensures that the pathogen population is reduced to an undetectable level.
Sodium chlorite solution with water and carbon dioxide can be extracted via port 2920. The fat and sodium compound(s) with excess water can be extracted via port 2932. Excess water is removed, in part, by entrainment with the carbon dioxide gas when vented.
The extracted liquid fat can then be separated from the sodium compound solution removed therewith by centrifuge or a separation column. Fat can then be pasteurized by elevating the temperature to a range of about 140° to about 160° F., filtered, and processed, such as by freeze-drying.
The apparatus can enable the application of high concentrations of sodium chlorite solution mixed with the meat to ensure adequate contact and saturated coverage of all exposed surfaces of meat, followed by adequate concentrations of carbonic acid solution at a pH of about 2 to about 3, thereby enabling reduction of pathogens to an undetectable pathogen population in the finished boneless meat.
Another aspect of the invention relates to a method and apparatus for processing meat by providing at least two input streams of ground meat to a mixer, controlling the mass flow of each stream, measuring at least the fat content of each stream, and combining the streams into a single output stream and measuring the fat content of the combined stream; adjusting the mass flow of the input streams to produce blended ground meat with a selected proportion of fat, lean, and water. The present invention can provide for the detection of measurement readings that have drifted from actual, and the manipulation of measurement readings to provide more accurate control of the controlled variable in meat, whether it is fat, lean, or water.
The methods and apparatus use measuring devices that may require periodic calibration. Such calibration has hitherto required an intervention procedure resulting in lost production time and the need to occasionally reprocess “out of specification” ground meat that has been produced with defective measuring devices that have not been correctly calibrated.
The present invention provides a method of operation and an automated process to enable calibration of measuring devices used in the automatic production of ground meat.
According to one embodiment of the invention, a method of controlling the rate of a pump for an input stream to a mixer having a plurality of input streams being mixed into an output stream is provided. The method includes obtaining a plurality of composition measurements of an input meat stream being transferred by a pump. The method includes calculating a representative measurement based on the plurality of measurements. The method includes determining the flow rate capacity of the pump based on a controllable pump factor. The pump factor can include the speed. The method includes calculating the controllable pump factor that is calculated to give an input meat flow rate that will provide a meat product within a composition range and a flow rate range, wherein the meat product is comprised from at least two input meat streams of different compositions. The input meat flow rate is obtained by solving a mass balance equation around the mixer using the representative measurement to solve for the input meat flow rate.
According to another embodiment of the invention, a method of selecting one measurement reading from a pair of measurement readings, to use as a measured variable in the control of an input stream to a mixer having a plurality of input streams being mixed into an outlet stream, is provided. The method includes obtaining the composition measurement readings from input streams and the output stream around the mixer. The method includes calculating obtaining the flow rates of input streams and the output stream around the mixer. The method includes calculating a predicted input stream composition by solving a mass balance equation around the mixer using the flow rates and the composition measurement readings, but for the one composition being solved. The method includes calculating the difference between the predicted input stream composition and the composition measurement reading from a measuring device from the same input stream. The method includes selecting the measurement reading from a redundant measuring device for use as the measured variable when the absolute value of the difference is outside of a threshold.
According to one embodiment of the invention, a method of detecting inaccuracy in a measuring device of an input stream to a mixer having a plurality of input streams being mixed into an output stream is provided. The method includes obtaining composition measurement readings from input streams and an output stream around the mixer. The method includes obtaining the flow rates of input streams and the output stream. The method includes calculating a predicted input stream composition by solving a mass balance equation around the mixer using the flow rates of the composition measurement readings, but for the one composition being solved. The method includes calculating the difference between the predicted input stream composition and the composition measurement reading from a measuring device from the same input stream. The method includes determining if the measuring device is inaccurate when the absolute value of the difference is outside of a threshold.
According to one embodiment of the invention, a method of calibrating a first measuring device from a second measuring device on an input stream to a mixer having a plurality of input streams being mixed into an output stream, is provided. The method includes obtaining composition measurement readings from input streams and an output stream around the mixer. The method includes obtaining the flow rates of input streams and the output stream around the mixer. The method includes calculating a predicted input stream composition by solving a mass balance equation around the mixer using the flow rates and the composition measurement readings, but for the one composition being solved. The method includes calculating the difference between the predicted input stream's composition and the composition measurement reading from a measuring device from the same input stream, and assigning the measurement reading from the second measuring device to the first measuring device when the absolute value of the difference is outside of a threshold.
In all the above alternative embodiments, measurement readings can be taken from all input streams and output streams. In all the above embodiments, the flow rates of input and output streams can be determined from a controllable pump factor or by measuring. Alternatively, some input streams will have a known and substantially unvarying composition. Also, their flow rate can be substantially unvarying. These known factors can still be used in solving the mass balance equation. However, due to their unvarying composition and flow rate, the composition need not be measured nor their flow rate determined.
The methods and procedures disclosed herein enable automated calibration of each measuring device during the normal operation of the apparatus, when measuring the content of each stream.
Automated production of ground meat, having a specified amount of fat, lean, and water content in any desired ratio, is enabled by combining at least two input streams of ground meat, pumped through conduits by variable-speed pumps, and mixed together to provide one output stream having the controlled variable within a specified range. The output stream can be produced within a specified flow rate range. The pumps are capable of adjusting the mass flow of each input stream to achieve an output stream within a specified composition and flow rate range. The mass flow of each input stream is adjusted according to the measured fat, lean, and/or water content of each input stream so that, when the streams are combined into a single output stream, the resultant fat, lean, or water ratio in the combined output stream is controlled within the specified range. The pumps are monitored for flow rate in an effort to maintain the output stream within a specified flow rate range. Pumps can be constrained from exceeding the upper limit of the output stream's flow rate. Pumps can also be constrained from dropping the output stream's rate below the lower limit of the output stream's flow rate range. It is not entirely necessary to maintain the input streams at any specified constant ratio prior to mixing the streams together. The variable that is desired to be controlled in the output stream may be allowed to vary in the input streams because the measuring devices measuring the input stream's composition immediately downstream of the pumps will adjust the flow rate of each input stream in the correct proportions to produce a mixed output stream having a controlled amount of fat, lean, or water, in any desired range. Measuring devices are installed in each of the input streams and also in the combined output stream. Mass flow adjustment of each stream is controlled by a computer that processes data received from each measuring device, and then directs adjustment of each pump's speed independently, according to the measured content of each stream, so as to produce an output stream of specified ground meat. The processing of data from the measuring devices in the manner described herein is useful to control the input stream meat pumps, or in detecting drift seen in some measuring devices, or in selecting one from a pair of measuring devices. The method for automated ground meat production, according to the invention, has been found to be a significant improvement compared with other production methods. However the accuracy of the streams' content measurement reading is affected by a gradual divergence from a calibrated setting and recalibration may be required periodically. In one embodiment, the present invention provides a method for detecting when a measurement reading has drifted, and selecting an alternative reading. Drift when used in the context of measuring devices refers to deviation of measurement readings from the true reading, which may occur gradually.
In one embodiment, two separate quantities of boneless meat with differing quantities of fat, lean, or water, are loaded into loaders 3402 and 3426. Boneless meat, such as beef, may be chilled prior to loading, to a temperature in the range of about 28° to about 45° F., but most preferably to a temperature of about 35° F.±1° F.
The second stream of boneless meat represented by arrow 3428 is processed in much the same manner as is the first stream of boneless meat represented by arrow 3400.
The first stream of boneless meat is loaded into a variable-speed meat grinder 3406 by loader 3402 and conveyor 3404, which may be fitted with a metal detector. Grinder 3406 is driven most preferably by a variable-speed motor, which may be a hydraulic motor, and in such a manner that will enable a continuous flow of meat to be ground at a mass flow that can be varied as required to adjust to the demands of the system and, more particularly, the proportioned flow into continuous blender 3414. For example, grinder 3406 may have level-indicating devices that monitor the levels in the meat grinder vessel and the grinder can be sped up or slowed down to maintain the level within a suitable range. Grinder 3406 is arranged to transfer ground meat along an enclosed conduit 3472 through measuring device 3408 and into preblender 3412. Grinder 3406 can be covered, apart from an open section to allow meat to drop into the hopper. The measuring device 3408 can measure the fat, lean, and water content in the first stream of meat. Preblender vessel 3412 receives product pumped therein, and blends the stream of ground meat while transferring said meat to the continuous mixer 3414. The preblender vessel 3412 is fitted with impellers mounted internally that are arranged to blend meat transferred therein and also to carry it toward the continuous mixer 3414. The impellers mounted in preblender vessel 3412 may be arranged with any suitable profile including paddles and Archimedes screw sections to enable efficient blending and removal of gas that may otherwise become entrapped within the meat stream as it is transferred into conduit 3470 by pump 3484. The meat pump 3484 can be a positive displacement piston-type pump, vane pump, or screw pump that may be a matching twin screw or single screw, having a parallel or conical profile, to increase pressure. The preblender vessel 3412 can also be provided with level indicators that will indicate the level of the meat in the vessel. If the level indicators indicate a high level, the grinder 3406 may be slowed down or temporarily stopped. Alternatively, the pump 3484 may be sped up to decrease the level in the preblender.
The type of pump 3484 may be selected from any number of pumps and may comprise, for example, a pair of counter- or corotating, meshed, conical screws arranged to compress the stream of meat and diminish any gas voids contained within the meat stream. Such gas inclusions can comprise a large proportion of carbon dioxide, which can dissolve into the water and oils contained in the meat when suitably compressed. Preblender vessel 3412 is also fitted with an exhaust duct 3484 so as to allow extraction of gases, such as carbon dioxide, that can be injected into vessel 3412 through bottom injectors, which can also enable the adjustment of the temperature of the meat blended therein. Gas supply source 3430 will supply liquid carbon dioxide to vessels 3412 and 3406. Carbon dioxide liquid will vaporize immediately after release by control valves, which can be used to control the temperature. Exhaust duct 3434 for vessel 3412 can be fitted with an extractor fan or may have a butterfly valve to maintain or control a selected pressure in the vessel. Exhaust duct 3434 will thusly carry any vaporized amount of water and can be used to control the water content in the meat stream.
From pump 3484, meat is transferred through conduit 3470 with measuring devices 3438 and 3440 conveniently mounted therein, and into the continuous blender 3414. Continuous blender 3414 is a mixer to mix the first and second input streams.
The second stream of boneless meat is loaded into a variable-speed meat grinder 3422 by loader 3426 and conveyor 3424, which may be fitted with a metal detector. Grinder 3422 is driven most preferably by a variable-speed motor that may be a hydraulic motor and in such a manner that will enable a continuous flow of meat to be ground at a mass flow that can be varied as required to adjust to the demands of the system and, more particularly, the proportioned flow into continuous blender 3414. For example, grinder 3422 may have level-indicating devices that monitor the levels in the meat grinder vessel and the grinder can be sped up or slowed down to maintain the level within a suitable range. Grinder 3422 is arranged to transfer ground meat along enclosed conduit 3474 through measuring device 3420 and into preblender 3416. Grinder 3422 can be covered, apart from an open section to allow meat to drop into the hopper. The measuring device 3420 can measure the fat, lean, and water content in the second stream of meat. Preblender vessel 3416 receives product pumped therein, and blends the stream of ground meat while transferring said meat to the continuous mixer 3414. The preblender vessel 3416 is fitted with impellers mounted internally that are arranged to blend meat transferred therein and also carry it toward the continuous mixer 3414. The impellers mounted in preblender vessel 3416 may be arranged with any suitable profile including paddles and Archimedes screw sections to enable efficient blending and removal of gas that may otherwise become enclosed within the meat stream as it is transferred into conduit 3471 by pump 3486. The meat pump 3486 can be a positive displacement piston-type pump, vane pump, or screw pump, which may be a matching twin screw or single screw having a parallel or conical profile to increase pressure. The preblender vessel 3416 can also be provided with level indicators that will indicate the level of the meat in the vessel. If the level indicators indicate a high level, the grinder 3422 may be slowed down or temporarily stopped. Alternatively, the pump 3486 may be sped up to decrease the level in the preblender.
The type of pump 3486 may be selected from any number of pumps and may comprise, for example, a pair of counter- or corotating, meshed, conical screws arranged to compress the stream of meat and diminish any gas voids contained within the meat stream. Such gas inclusions can comprise a large proportion of carbon dioxide that can dissolve into the water and oils contained in the meat when suitably compressed. Preblender vessel 3416 is also fitted with an exhaust duct 3452 so as to allow extraction of gases, such as carbon dioxide, that can be injected into vessel 3416 through bottom injectors, which can also enable the adjustment of the temperature of the meat blended therein. Gas supply source 3456 can supply liquid carbon dioxide to vessels 3416 and 3422. Carbon dioxide liquid will vaporize immediately after opening of control valves to control the temperature. Exhaust duct 3452 for vessel 3416 can be fitted with an extractor fan or may have a butterfly valve to maintain or control the pressure in the vessel. Exhaust duct 3452 will thusly carry any vaporized amount of water and can be used to control the water content in the meat stream. Gas supplies 3430 and 3456 are fed to grinders 3406 and 3422 and preblenders 3412 and 3416 to displace air and oxygen.
From pump 3486, meat is transferred through conduit 3471 with measuring devices 3446 and 3448 conveniently mounted therein, and into the continuous blender 3414. Continuous blender 3414 is a mixer to mix the input streams. Continuous blender 3414 is preferably controlled within a specified flow rate range. Accordingly, the control of pumps 3470 and 3471 may be arranged to cooperatively produce a combined flow rate that will neither exceed the upper limit of the range nor drop the flow rate below the lower limit of the range. For example, one pump can be selected as the master of the combined flow controller; however, if the pump were to reach its operating limit, the slave or second pump may be engaged in combined flow control mode. Pumps will typically operate in composition control mode, but flow will be monitored and controlled as well. Operation of the pumps may result in constraining the pump speed not to increase or decrease if it would result in the combined output stream being outside the combined output composition range. Back pressure in conduits 3470 and 3471 is created by controlling the flow of combined streams through the continuous blender 3414.
Each stream of boneless beef that has been ground is preferably fed into preblenders 3412 and 3416. Blending each stream in isolation, prior to combining with another stream, can provide a substantially homogenous stream of meat that can decrease the variation in measurements taken by measuring devices 3438, 3440, 3446, and 3448, respectively. The pressure in the preblenders can be elevated by controlled restriction of the exhaust, which will prevent ingress of atmospheric oxygen.
The equipment is arranged to automatically measure at least one component of each stream of meat coming into the continuous blender. The measured component may be fat, lean, and water or any other component or characteristic of the meat. The measurements are made as the streams are transferred through measuring devices 3438, 3440, 3446, and 3448, installed after pumps 3484 and 3486, measuring devices 3408 and 3420 installed after grinders 3406 and 3422, and measuring devices 3478 and 3460 installed after the continuous mixer. The measuring devices can be GMS and/or AVS devices. The measuring devices, which are preferably of the GMS type, are integrated into the conduits to enable automatic measuring of the meat properties, which may include but are not limited to, weight, water content, fat content, and lean content, thereby enabling the automatic adjustment of the pumps 3484 and 3486.
Additionally, all vessels, equipment, and connecting conduits can be filled with selected gases as required. The gas may comprise at least carbon dioxide or nitrogen. But in any event, the gas should have reduced amounts of oxygen in proportions lower than normal air. The continuous blender 3414 is driven by a variable-speed motor, thereby combining first and second streams into a single stream that is transferred through blender 3414 and mixed therein by screws enclosed therein. The combined and blended stream of meat can be transferred through conduit 3458 and through measuring devices 3478 and 3460. Conduit 3458 is connected to hopper 3462 with an optional positive displacement pump 3476 at one outlet. It should be noted that the continuous blender 3414 has adequate capacity to pump the combined streams and a fine grinder could be mounted directly to the exit end of the continuous blender if so desired. Pump 3476, optionally can be provided with a grinder to finely grind meat. Hopper 3462 can be arranged with a conical profiled side elevation and can be fitted with a mixer mounted therein. The variable-speed, positive-displacement pump 3476 is connected directly to the base of the conical profiled hopper 3462 so as to enable a controlled pumping of the stream of meat into conduit 3464. Conduit 3464 may be arranged with an outer jacket in a manner to allow heated water to pass therethrough, enabling the heating of the conduit 3464. Such heating can minimize the buildup of fat on the internal walls of the conduit 3464, which may otherwise accumulate excessively.
In one embodiment, conduit 3464 is connected to a chub packaging apparatus 3466 with a chub clipping and transfer section. Filled, clipped, and sealed, substantially oxygen-free chubs, which may also be evacuated, are then transferred onto conveyor 3468. Conveyor 3468 is arranged to transfer finished chub packages into a refrigerated storage room and labeling station, and/or further packaged into cartons that can then be loaded onto pallets in readiness for shipping. Chub packages can be labeled or marked with an identification mark that is associated with all types of information that can be retrieved via a computer.
Continuous blender 3414 may be provided with an enclosed screw-style transfer and blender driven by a variable-speed driver. Alternative mixing devices can be integrated into the automated ground meat production system, as herein described. For example, grinders 3406 and 3422 may be used to blend the combined first and second streams of meat.
Measuring devices 3408, 3420, 3438, 3440, 3446, 3448, 3478, and 3460 may be used to measure the fat, water, and/or lean content of meat streams transferred therethrough. However, when GMS measuring devices are installed in close proximity to each other, the operation of each device, when taking a measurement reading, should be staggered so that only a single device is actively measuring at any one time. The GMS devices utilize microwave (radio frequency) and interference can occur between the devices when operated at the same time. Staggering the operation of the devices may avoid interference. The GMS devices are capable of actively measuring at a rate of approximately 1-2 times per second. For example, device 3408 may be activated to read a first measurement followed in sequence by device 3438, then 3440, 3420, 3448, 3446, 3478, and 2460. Following the completion of such a sequence of measurements, the sequence can be repeated for any number of cycles. However, it should be appreciated that the order of measurements may be altered in any manner. In one embodiment, every measurement reading from one device is added and divided by the number of readings taken from the device to arrive at an average reading. Other embodiments may obtain the median reading of all the measurement readings. Both the average and median readings are representative readings from a sampling of the readings taken from one measuring device. It is also possible to have more than one measuring device at one stream, i.e., pairs of measuring devices or redundant measuring devices. The readings from one or from all measuring devices on one stream can be used to obtain an average measurement or a median measurement. The representative reading obtained from a plurality of readings is used in computations to control the apparatus, as further described below. Additionally, it should be noted that the measurements are taken while each stream of meat is in motion. The average quantity of meat measured can vary according to the mass flow of each stream. Therefore, it is preferable to vary the sequence of measurements for every cycle and, preferably, a random order can be performed from a virtually infinite combination of sequences.
During each sequence or series of measurements, the data from each measuring device is recorded in isolation from other device measurements. In this way, a progressive history of measurements can be recorded in a computer. The computer can include a database structure stored in memory. The memory can comprise a RAM component and also a storage hard drive component. In this way, any number of selected measurements from any particular measuring device can be accumulated and a representative measurement is calculated for each measuring device. The representative measurement can be an average or median, or any other measure derived from a sampling of readings that is representative. In one embodiment, for example, the sum of three consecutive measurements from any one measuring device can be selected and averaged to yield the average of the three consecutive measurements. In other embodiments, the measurements of pairs of measuring devices are added and divided by the number of measurements taken from both instruments. The representative measurement, from the subject measuring device or devices, having measured one particular stream of meat, can then be used in the computations for the adjustment of the pump associated with the stream with improved accuracy. Similarly, selected consecutive measurements from any and all measuring devices can be stored, and processed to provide representative measurements that can then be used to adjust the flow of the associated stream with pumps. Furthermore, the sum of any number of consecutive measurements can be averaged, over time, to provide such measurements for mass flow control of each stream. Alternating measurements from two or more measuring devices according to any pattern, random or otherwise, can be accumulated, and averaged to achieve an improved performance of the automated apparatus for ground meat production. Any trends that may be caused by measuring device malfunction or meat variations can be identified and adjusted as needed without the intervention of an apparatus operator, according to the invention. Examples of recorded measurement data manipulation, for the purpose of improving ground meat production efficiency, can involve programming of the computer to perform numerous simultaneous calculations so as to optimize use of the recorded measurement data that, for example, can include the continuous calibration or adjustment of the measuring devices.
In practice, accumulating data from several consecutive measurements, followed by an averaging of the accumulated measurements is a preferred method to achieve an improved homogenized blend of ground meat. The data can also be used to check and then calibrate or adjust the paired devices, determine when a device has drifted, select an alternate device, and control the mass flow of the pumps based on the correctly functioning device. In
Referring again to the devices shown as A, a, B, b, C, and c, other calculations can be programmed into the computer processor. For example, in addition to the calculation of A+B=C, the following equations can be used to check accuracy and performance of any individual device, wherein any letter represents a mass quantity, calculated by multiplying mass fraction with mass flow or by any other determination.
In the event that any particular device is found to malfunction, it can be recalibrated, meaning that, if a measuring device is determined to be reading inaccurately, the signal by the malfunctioning device, is set to equal the measurement of the properly functioning device. Alternatively, the malfunctioning device can be excluded from subsequent calculations until it can be replaced or repaired, and the functioning device can be selected to take its place.
Any of the vessels disclosed herein for treatment requiring the addition of carbon dioxide can be arranged in any suitable disposition, horizontal, vertical, or inclined to enable, in particular, the efficient separation of any agent, but most notably liquid or very dense carbon dioxide, and which may include a measured/determined quantity of added water, and meat. For example, it may be more suitable to treat the meat in a horizontally disposed vessel with paddles therein, and then extract the treated meat from the horizontal vessel, after any suitable treatment with any selected agent, with a vertically or inclined screw, such that the meat has gaps between the pieces allowing the agent, such as liquid carbon dioxide, to remain in the lower portion of the vessel. In this way, the liquid or dense gas carbon dioxide can be substantially removed from the meat prior to any compression of the meat.
It is believed that the composition of bacteria cell walls (at least with respect to the cell walls of the pathogens E. coli 0157-H7, salmonella, and listeria monocytogenes) is a complex arrangement of lipids (fats). Given that liquid carbon dioxide, such as supercritical carbon dioxide, is a powerful solvent and will dissolve fats very aggressively, it may be that the carbon dioxide dissolves the bacteria cell walls thereby, selectively, killing these pathogens and dissolving fat, such as in the meat, at the same time. The dissolution of lipids in cell walls can occur very rapidly, and can enable the size of the treatment vessel to be greatly reduced when compared to a vessel relying only upon lowering of the pH of the carbonic acid to kill the bacteria.
According to one embodiment of the invention, the goods, such as meat, can be treated in a first chamber with liquid carbon dioxide at a temperature above the freezing point of water, such as in the range of about 34 to about 40° F., and at a pressure of about 500 psig to about 750 psig, or greater. Liquid carbon dioxide can liquefy fat which can be extracted therewith. The goods, such as meat, are treated in a second chamber wherein a measured amount of water is added with additional carbon dioxide to produce carbon acid having a pH of about 2 to about 3. Thereafter, the meat can be further processed, such as by grinding. Grinding meat greatly increases the amount of surface area, and therefore it is more effective to treat the meat prior to any substantial increase in the surface area.
The water added to the meat must not exceed an amount equal to the lost water plus less than 0.5% to avoid labeling retail packaged meat with the amount of added water (to the nearest whole number), or alternatively if the amount of added water exceeds the lost water (which has been lost due to evaporation and/or sublimation of frozen, natural water/ice content of the meat) by an amount greater than 0.5%, and less than 1%, a retail package containing the meat must be labeled with the words “1% added water” and so on.
Referring now to
After separation, a first stream of fat can be extracted via conduit 160 in the direction shown by arrow 158, and a second stream of lean beef can be extracted via a conduit in the direction shown by arrow 196. The apparatus shown in
The annular space defined by and between dotted line 162 and the internal face of conduit 186 shows a fraction of the internal space of conduit 186 where the most dense material, i.e., lean meat such as lean beef will accumulate; the dotted lines 162 and 172 define the outer extremities of an annular space wherein fluid and/or liquid carbon dioxide will accumulate and the annular space defined between dotted lines 172 and 181 comprises the annular space in which the least dense ground meat fat component will accumulate after centrifuging therein.
The assembly shown in
More particularly, a planetary gear arrangement can be provided so as to connect the outer conduit 186 via an end section and shaft 108, through a planetary gear arrangement having a suitable ratio such that the Archimedes screw assembly will rotate relative to 186 at a speed sufficient to transfer all stratified goods from within the centrifuge at a suitable rate approximately equal to the rate of mass flow of goods transferred into said conduit 186. Ground meat and liquid carbon dioxide transferred into spaces such as 118 and 110 will stratify in such a manner that the lean component of the ground meat being of greater density than the fat component, will stratify within space defined by the outer annular ring defined by dotted lines 105 and 162 and against the inner surface of conduit 186 such as into space 176 and generally between the inner surface of 186 and a line shown by dotted lines 162 and 105. Fat component will stratify generally within dotted lines shown on either side of space 122 and 172. Liquid CO2 will accumulate in the space 118 defined by dotted lines 105 and 113 and in space 172 flanked by dotted lines 173 and 181. As the Archimedes screw assembly rotates, lean meat is carried by the Archimedes screw comprising at least one continuous spiral strip of steel such as shown by 190 and 120 thereby transferring the lean beef along the internal surface of cone 109 toward a centrally disposed conduit 106 across face 193 and into conduit space 106 and there from through conduit 199 in the direction shown by arrow 196. A positive displacement pump is connected directly to conduit 199 and transfers goods there through at a controlled rate proportional to the ground meat being transferred into the space in conduit 186. Ports 126 and 170 in conduits 169 and 125 allow surplus liquid CO2 to be transferred through space 168 into annular manifold 165 and through conduit 132 in the direction shown by arrow 134. Conduit 132 is connected directly to a pressure and mass flow controlling, second positive displacement pump. A third pressure and mass flow controlling, positive displacement pump is connected directly to conduit 160 such that fat can be extracted there through in the direction shown by arrow 158. It can therefore be seen that first, second and third positive displacement pumps (not shown) respectively connected directly to conduits 199, 132 and 160, are controlled via a central computerized controlling system in such a manner that goods transferred by means of controlled variable speed positive displacement pumping in the direction shown by arrow 152 and through grinder 148, plus liquid carbon dioxide transferred through conduits 156 and 142 which is also transferred there through by positive displacement pumping means are substantially of equal mass and balanced such that the mass of goods pumped into space within conduit 186 are equal to the mass of goods pumped from the space within conduit 186. Additionally, conduit 108 provides a means of injecting gaseous phase carbon dioxide into space such as 110 via apertures such as 204. In this way, the quantity of liquid CO2 that is transferred from the vessel 186 with goods can be minimized. Gaseous phase carbon dioxide or any other suitable gas such as nitrogen and/or a blend of carbon dioxide and carbon monoxide, wherein the carbon monoxide content is not more than 0.4% by volume (or weight) is transferred into space 110 at a controlled mass flow and maintained at a suitable volume in space 110. In summary it can be seen that fat accumulating at layer 122 and 172 can be transferred from the apparatus via conduit 160 by rotating the Archimedes screw assembly and simultaneously lean meat accumulating in spaces at 176 and 119 is transferred through conduit 195 into space 106 and via conduit 199 in the direction shown by arrow 196, and liquid carbon dioxide is extracted via conduit 132 in the direction shown by arrow 134. The combined mass flow of goods extracted through conduits 199, 132, and 160 is measured by positive displacement and controlled in direct proportion to the goods transferred through grinder 148 and space 146, blended with liquid carbon dioxide and pumped into the space within the separating system including space 192 and or 110, for example. Liquid carbon dioxide extracted via conduit 132 can be recycled after sanitizing, filtering and adjusting so as to meet specified pressure and temperature settings as required, and into conduits 142 or 156 by positive displacement pumping from and into the spaces within the centrifuge body 186. The temperature of liquid CO2 is generally required to be maintained in the order of about 38° F. or less or more.
In yet another preferred embodiment a pair of (two) separators, similar to the apparatus shown in
Centrifuges and most particularly “decanting” style centrifuge equipment such as equipment, manufactured by B & P Process Equipment, which can be seen at website http://www.bpprocess.com/ or as manufactured by Centrisys Corporation, 9586 58th Place Kenosha, Wis. 53144, which can be seen at website http://www.centrifuge-systems.com/ do not provide for pressurized, temperature controlled and enclosed processing capability for the “3 phase” separation of two solids and one liquid. The equipment disclosed herein does provide for the separation of two solids (i.e., fat and lean beef) and one liquid (liquid CO2) and wherein the liquid (CO2) is a gas at ambient atmospheric conditions. In this way the liquid CO2 can be used as an agent facilitating the separation of the two solids (fat and lean beef) and after use of the liquid for this purpose, the liquid evaporates leaving no residue with the solids.
While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.