Patent Application
20120141645
1. Field of Invention
This invention relates generally to sparse lean processing and, more particularly, to separating fat from lean in a sparse lean.
2. Background Art
Attention within the meat industry has been recently drawn to the dangers of diets high in fat, especially as high fat diets have been implicated in an increased incidence of diseases of blood vessels, such as coronary heart disease and arteriosclerosis. As a consequence, the medical profession has suggested that the consumption of fat should be reduced. One way to accomplish this is to eat meats that have been processed so that they contain a reduced amount of fat.
One method to reduce the amount of fat in meat is simply to manually cut fat from the meat. Meat having higher amounts of fat is cut or trimmed from meat having lower amount of fat (meat that is more lean). The resulting trimmings are merely separated by operators with sharp cutting utensils. However, manually cutting more fatty portion from the more lean portions, for example, is not effective in reducing the fat content of the remaining more lean portions to lower than about five percent. In addition, this process does not assist in recovering any further lower fat lean portions from the trimmings. Further, skilled workers and time are required to cut the meat, thus making the process expensive and inefficient, further necessitating the need to recover usable lean from the trimmings. Further, the trimmings or sparse lean is now an undesired portion of the primal cut and it is not economical to make the sparse lean into a ground product due to its high fat content. Without further processing to remove fat, the product would be sold as low value rendered product.
In an attempt to reduce the fat content of meat and meat trimmings other processes have been proposed and utilized. These processes typically employ one or more of the following approaches. First, the fat can be freed from meat by mechanical techniques, such as by the use of a grinder, a crusher, a press, a comminutor, or a micro-comminutor. These procedures have been employed with or without accompanying high temperatures. Physical extraction techniques have also been utilized, such as the use of heat, and reaction of gases with meats, including fluid extraction. Fat has also been removed employing chemical extraction techniques, such as the use of chemical reagents, including acids.
Unfortunately, these techniques generally have a detrimental impact on the meat or alter the meat's protein profile, vitamin profile, color, texture and/or water content. For example, high temperatures denature meat. The use of diluents, such as water, can leach water-soluble proteins and vitamins from the meat and can increase the moisture content of the defatted product. Additionally, when diluents are used with micro-comminution of meat, the functional properties of the resulting product can be adversely affected. The use of chemical reagents, acid or alkaline treatment of meat facilitates the binding of anions or cations, respectively, to the protein, thereby adversely affecting the meat's properties.
Moreover, it is often the subsequent separation step that is critical to the success or failure of a defatting process. Even if a substantial amount of fat is initially liberated from the meat, unless the fat is effectively separated from the meat, the process will not be a success. For example, even if the proper choice of conditions for grinding or comminuting meat produces a substantial fat-containing fraction, conventional devices, such as conventional decanter centrifuges, are not completely effective in separating the resulting fractions.
Decanter centrifuge methods have also been utilized for producing lower fat lean meat having substantially the same functionality, protein profile, vitamin profile, color, texture and water content as the raw meat starting material. The reduced fat meat, however, can often contain from about 0% to 10% fat and can have a substantially reduced level of cholesterol. The decanter centrifuge can have a hollow, centrifugal rotor with a longitudinal axis of rotation a. The centrifugal rotor defines a generally cylindrical bowl tapered at one end to form a beach. The centrifuge also can have a feed tube for introducing starting material into a delivery zone in the interior of the cylindrical bowl and a fluid inlet tube for proportionately metering a fluid into the feed tube. A screw conveyor, can be disposed in the cylindrical bowl to cause a substantially solid portions to be discharged out of at least one solid discharge port located at the tapered end of the rotor and a substantially liquid fraction to be discharged out of at least one liquid discharge port located at the opposing end of the rotor.
Further, Low temperature rendering processes have been used to separate protein from fatty tissue in animal trimmings. The processes generally involve comminuting fatty tissue from animals, such as hogs or cattle, to form a semi-solid slurry or meat emulsion, heating the slurry or emulsion to melt the fat, and then separating the fat and protein by centrifugation. The protein can then be used as an ingredient in processed meat products such as sausage and other cured and processed meats. It has been found that the protein or meat provided by prior art low temperature rendering processes suffer from undesirable flavor changes shortly after production. In order to reduce the flavor changes after low temperature rendering processes, some process use a conditioning agents which reacts or combines with the pigments of the meat to reduce the activity of the pigments which catalyzes the development of off-flavor.
The government provides that a certain quality of meat product obtained from animal trimmings can be used undeclared in meat products of the same species. For example, “finely textured beef” and “lean finely textured beef” can be used in ground beef without being declared on the label. “Finely textured meat” is required to have a fat content of less than a defined percent; a protein content of greater than a defined percent. “Lean finely textured meat” is required to have a fat content of less than a defined percent, by weight, and complies with the other requirements of “finely textured meat.”
A low temperature rendering process can include the process steps of: heating desinewed animal trimmings in a heat exchanger having a first-in and first-out arrangement to provide heating of the desinewed animal trimmings to a temperature in the range of about 90.degree. F. to about 120.degree. F. to form a heated slurry; separating a solids stream and a liquids stream from the heated slurry, the solids stream containing an increased weight percent of protein and moisture compared with the weight percent of protein and moisture in the heated slurry, and the liquids stream containing an increased weight percent of tallow compared with the weight percent of tallow in the heated slurry; separating a heavy phase and a light phase from the liquids stream, the heavy phase containing an increased weight percent of moisture and water soluble protein compared with the weight percent of moisture and water soluble protein in the liquids stream, and the light phase containing an increased weight percent of tallow compared with the weight percent of tallow in the liquids stream; and combining the solids stream and the heavy phase to form a meat product. Preferably, the meat product has a fat content of less than 30%; a protein content of greater than 14%; and a protein efficiency ratio of 2.5 or higher, and an essential amino acids content of at least 33% of the total amino acids. In a preferred embodiment, the animal trimmings are processed in closed environment so that atmospheric oxidation is reduced. In addition, the animal trimmings are preferably not heated above 110.degree. F. in the heat exchanger, and are not treated with chemicals or additives.
The step of separating a solids stream and a liquids stream from the heated slurry can occur in a decanter, and the step of separating a heavy phase and a light phase from the liquids stream can occur in a centrifuge, and the meat product can be frozen within about 30 minutes of heating the desinewed animal trimmings in a heat exchanger. The meat product prepared by the low temperature rendering process is preferably finely textured meat. Preferably, the low temperature rendering process is continuous, but can be modified for batch or semi-batch operations. However, even at the temperature levels of these so-called low temperature processes, microbial growth is likely to occur and the appearance and texture of the lean material will likely be negatively impacted. Therefore, a better process is needed.
The invention is a non-destructive lean recovery apparatus and method for separating lean and fat animal tissue in sparse lean products, such as for example, meat trimmings. The invention exploits the fact that lean and fatty tissue have distinctly different specific gravities. The invention impacts the sparse lean material with a force, which breaks the lean material into small pieces of fat and lean material thereby separating the fat portions from the lean portions. The sparse lean material can be initially ground through a grind plate and the ground material can be suspended in a water bath and agitated with sufficient force to separate the fat from the lean material. Other means of force applied in the water bath can be utilized such as for example forces applied by compress air or mechanical forces applied by blades. As the forces are applied and the separation occurs, due to the different specific gravities of the lean and fat, the fat will tend to float to the surface of the water bath and the lean material will tend to sink in the water bath. More specifically, material having a percent lean greater than about approximately 70% will tend to sink in the water bath whereas the more fatty material will tend to float on the top. The term sparse lean is used throughout, however, any type of lean starting material can be used.
One embodiment of the invention can include, a grind plate that is about approximately ⅜ inch (other sizes can be utilized for greatest efficacy, which may vary depending on the source and type of mater being process), a water bath having an agitation or force inducing mechanism (for example a rotating blade, though other means of agitation can be utilized), a settling basin where the agitated material will flow and where the fat can float and the lean can sink below the surface, a fresh water flow mechanism or a mechanical skimmer (for example a skimming conveyor) operable to remove the fatty material from the top of the settling basin, a second fresh water flow mechanism or other mechanical traversing or transport mechanism (for example a conveyor or an auger) operable to remove the lean from the bottom of the settling basin, and a centrifuge or press operable to remove water from the separated lean material for further processing.
The temperature of the water can be about approximately 40 degrees Fahrenheit, which has an advantage over the typical heated centrifuge processes that attempt to liquefy the fat for separation, but have problems with microbial growth and problems that impact the appearance, characteristics and texture of the product. The appearance, characteristics and texture of the product utilizing the present invention is un-altered, particularly when operated at desired water temperatures, which can vary from about approximately 35 degrees Fahrenheit to about approximately 50 degrees Fahrenheit. Further, the removal of water from the separated lean material reduces any issues resulting from excess water.
Another embodiment of the invention is a method for recovery of lean from sparse lean including suspending sparse lean in water in a vessel having an agitator within said vessel and adapted to apply agitation forces to said sparse lean where said agitation forces provide sufficient impact forces to separate lean material portions from fat portions of the sparse lean by agitating the sparse lean with the agitator. A fresh water flow can be utilized to flow the separated lean material portions and the fat portions from the vessel into a settling basin and suspending the lean material portions and the fat portions in water in the settling basin. The lean material portions can be allowed to sink below the surface of the water contained in the basin and the fat portions can be allowed to float toward the top of the water contained in the basin. The floating fat portions floating toward the top of the water contained in the settling basin can be skimmed off and captured for further processing. The lean material portions sunk below the surface of the water contained in the settling basin can be removed by channeling through an exit port and captured for further processing. The agitator can be for example a rotating propeller blade or a compressed air jet. The step of skimming can be performed by skimming flaps projecting from an endless conveyor over the surface of the water in the settling basin. The method can further comprise the step of removing water from the lean material portions using a centrifuge. The water in said vessel and in said settling basin is maintained at a temperature from 35 degrees Fahrenheit to 50 degrees Fahrenheit in order to facilitate separation of the lean material portion and the fatty portions and to reduce microbial growth.
An alternative embodiment of the present invention includes an optional grinder pump and centrifuge combination in addition to or in lieu of the agitator of the present invention. The grinder and pump combination will output a slurry, which can be sent through a centrifuge or cyclone to further separate the lean from the fat.
These and other advantageous features of the present invention will be in part apparent and in part pointed out herein below.
For a better understanding of the present invention, reference may be made to the accompanying drawings in which:
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description presented herein are not intended to limit the invention to the particular embodiment disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
According to the embodiment(s) of the present invention, various views are illustrated in
One embodiment of the present invention comprising a grind plate that is about approximately ⅜ inch (other sizes can be utilized for greatest efficacy, which may vary depending on the source and type of mater being process), a water bath having an agitation or force inducing mechanism (for example a rotating blade, though other means of agitation can be utilized), a settling basin where the agitated material will flow and where the fat can float and the lean can sink below the surface, a fresh water flow mechanism or a mechanical skimmer (for example a skimming conveyor) operable to remove the fatty material from the top of the settling basin, a second fresh water flow mechanism or other mechanical traversing or transport mechanism (for example a conveyor or an auger) operable to remove the lean from the bottom of the settling basin, and a centrifuge or press operable to remove water from the separated lean material for further processing, teaches a novel apparatus and method for recovering lean from trimmings and the like in a non-destructive manner.
The details of the invention and various embodiments can be better understood by referring to the figures of the drawing. Referring to
The sparse lean product can be input into the agitator assembly by inputting and channeling the sparse lean product down the product chute 109. The sparse lean product will travel down the chute 109 into the agitator duct 206. The parse lean product can be manually deposited in the chute 109 or alternatively the sparse lean product can be automatically dropped on the chute 109 by way of a conveyance system. When the sparse lean product travels down the product chute 109 into the agitator duct 206, the sparse lean product will encounter an agitator within the duct 206, which will apply an impact force having sufficient force to separate the lean material portions of the parse lean product from the fatty portions. The agitator duct and surrounding capture vessel 108 is continuously being filled with water such that the water will overflow the capture vessel into the settling basin 110.
The agitator will force the product through the agitator duct and into the capture vessel 108 and the continuous water flow will cause the separated product to travel along with the overflow of water into the settling basin 110. Once in the settling basin 110, the separated lean material portions of the sparse lean product will tend to sink toward the bottom of the settling basin which is filled with water. The separated fatty portions of the parse lean product will tend to float toward the top of the water contained within the settling basin 110. The fatty portion can be skimmed off by the skimming conveyor system 112 or other skimming mechanism, for example a mechanical arm that skims the surface of the water with a sweeping motion. The fat can also or alternatively be allowed to flow thru the overflow channel 130 and dewatered with a similar device as 104 thereby, eliminating the need for a skimming conveyor.
The skimming conveyor system can include a conveyor motor, which drives an endless conveyor belt having conveyor belt flaps extending there from. As the flaps are conveyed along the bottom run of the endless belt, the flaps will skim off any floating fatty portions thereby removing them from the settling basin. The settling basin can also include an overflow drain channel 130 such that any water overflowing the settling basin can be channeled there through. The drain channel 130 can also export any fatty material not captured by the skimming conveyor system 112.
The lean material portion conveyor 104 can include an auger and an auger screen 118. Lean material portions can be channeled through the exit port 114 into the water velocity reducer 126 and further directed into the auger and auger screen 118. Once the lean material portions have been conveyed through the auger, the lean material portions can be captured manually or automatically conveyed to be inserted in the water extraction system 106. The water extraction system can include a centrifuge motor and centrifuge drive belt for turning the interior drum of the centrifuge within the centrifuge outer drum 128.
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The lean material portions can travel through the lean material portion exit port 114 when the lean material portion exit valve 308 is opened. The lean material portions can continue through the discharge pipe 304 and further into the water velocity reducer 126 of the lean material portion conveyor 104. The lean material portions can be channeled through the water velocity reducer 126 and into the auger 104. Then auger helix 202 can convey the lean material portions through the conveyor and the auger screen 118 will allow any excess water to drip from the lean material portions. This side perspective also shows the skimming conveyor system 112 having a fatty material discharge end 310 where the conveyor belt flaps 116 can push any fatty material captured by the conveyor through the discharge end 310. Lean material portions exiting the conveyor 104 can then be input into the water extraction system 106. This can be accomplished by manually feeding the separated lean material portions into the centrifuge or automatically inputting the separated lean material portions into the centrifuge by way of a conveyance system (not shown). Lean product could be transported using a screw or belt conveyor to 106 or 104 could be eliminated and water/lean discharge could be transferred to a decanter through a flume where the decanter would do the complete separation of water and solid lean portions.
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The top of the baffle 502 can be beneath the surface of the water which is filled to the rim of the settling basin such that the separated fatty material floating approximate the surface of the water and can travel over the funnel baffle 502. Lean material portions that have sunk beneath the top edge of the funnel baffle 502 will be directed downward toward the lean material portion output port 718. Item 710 shows the opening of the trough 710. The settling basin has slatted side walls 712 and 714 which will channel sinking lean material portions downward toward the trough and further toward the lean material output port. The funnel baffle 716 will urge the material downward in a similar manner.
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The agitator can force the product through the agitator duct and into the capture vessel and the continuous water flow from the illustrated Water Sanitation/Recirculation system will cause the separated product to travel along with the overflow of water into the settling basin 110, which is illustrated in the flow diagram as a sort tank. Once in the settling basin or sort tank, as illustrated, the separated lean material portions of the parse lean product will tend to sink toward the bottom of the settling basin which is filled with water. The separated fatty portions of the parse lean product will tend to float toward the top of the water contained within the settling basin. The fatty portion can be skimmed off by the skimming conveyor system or other skimming mechanism, for example a mechanical arm that skims the surface of the water with a sweeping motion. The fat can also or alternatively be allowed to flow thru the overflow channel and dewatered with a similar device as 104 thereby, eliminating the need for a skimming conveyor.
The lean material portion can be conveyed by a conveyor, which can include an auger and an auger screen. Lean material portions can be channeled through an exit port into a water velocity reducer and further directed into the auger and auger screen. Once the lean material portions have been conveyed through the auger, the lean material portions can be captured manually or automatically conveyed to be inserted in the water extraction/removal system as illustrated. The water extraction system can include a centrifuge motor and centrifuge drive belt for turning the interior drum of the centrifuge within the centrifuge outer drum.
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A hydro-cyclone has two exits on the axis: the smaller on the bottom for underflow and a larger at the top for overflow. The underflow is generally the denser or coarser fraction, which in this case could be the more lean, while the overflow is the lighter or finer fraction, which in this case could be could be the more fat. Internally, centrifugal force is countered by the resistance of the liquid, with the effect that larger or denser particles are transported to the wall for eventual exit at the reject side with a limited amount of liquid, whilst the finer, or less dense particles, remain in the liquid and exit at the overflow side through a tube extending slightly into the body of the cyclone at the center. Forward hydro-cyclones remove particles that are denser than the surrounding fluid, while reverse hydro-cyclones remove particles that are less dense than the surrounding fluid. In a reverse hydro-cyclone the overflow is at the apex and the underflow at the base.
The various non-destructive lean recovery examples shown above illustrate a novel method and apparatus for recovering lean from trimmings and the like. A user of the present invention may choose any of the above lean recovery embodiments, or an equivalent thereof, depending upon the desired application. In this regard, it is recognized that various forms of the subject non destructive lean recovery apparatus and method could be utilized without departing from the spirit and scope of the present invention.
As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. It is accordingly intended that the claims shall cover all such modifications and applications that do not depart from the sprit and scope of the present invention.
Other aspects, objects and advantages of the present invention can be obtained from a study of the drawings, the disclosure and the appended claims.
