Abstract:
Processing apparatus and method for meat, poultry and fish products include multiple successive immersions in sanitizing solutions at different temperatures within controlled environments including exposures to fluids at pressures different from ambient pressure to reduce resident microbial contaminants in preparation for packaging and distribution.

Description:
RELATED CASES 
       [0001]    This application is entitled to the benefit under 35 U.S.C. §120 as a divisional application of application Ser. No. 11/146,548 filed on Jun. 6, 2005 by M. Terry which is a continuation-in-part of application Ser. No. 10/140,735 filed on May 7, 2002 by M. Terry. The subject matter of this application is related to the subject matter of U.S. Pat. No. 6,551,641 issued on Apr. 22, 2003 to M. Terry, and is also related to the subject matter of U.S. Pat. No. 5,711,980 issued on Jan. 27, 1998 to M. Terry, and to the subject matter of U.S. Pat. No. 6,050,391 issued on Apr. 18, 2000 to M. Terry, which applications and subjects matter are incorporated herein in their entireties by this reference to form a part hereof. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to equipment and processes for processing fresh fish or poultry or meat to retard deterioration and promote extended shelf life. 
       BACKGROUND OF THE INVENTION 
       [0003]    Fish, poultry and meat products (i.e., animal products herein) are commonly processed from catch or slaughter to market distribution in cold or frozen condition to retard the rate of decay of the product attributable to microorganisms present in or on the product. Extended shelf lives for such 
         [0004]    products commonly result from maintaining the products in frozen conditions during final processing, packaging, distribution and display. However, for such products that are not conducive to processing, packaging, distribution or display in frozen condition, icing down or otherwise refrigerating such products to cool, non-frozen condition is an alternative procedure that attains some extension of shelf life though not as extensively as in frozen condition. However, frozen product once thawed and non-frozen product commonly deteriorate rapidly out of a cold or refrigerated environment. Such deterioration is attributable to microorganisms that remain on the surface of the product as well as within the product following initial processing, and that rapidly proliferate at elevated temperatures. In contrast to fresh produce that may be harvested in the field or orchard or vineyard and that is inherently immune from deterioration at the moment of harvest, fleshy products of fish, poultry and meat are notoriously more prone to rapid deterioration from the moment of catch or slaughter. 
         [0005]    Various types of bacteria that are commonly present, for example, on fish to be processed for distribution are believed to have many similar characteristics in their basic structure including porous cell walls comprised of mostly sugar molecules that are cross-linked by peptide bonds. This lattice-like structure provides rigidity and support to the cell to withstand the internal pressure on the cellular membrane created by the volume of the contents within the cell. 
         [0006]    Cells are believed to have selective cellular membranes that contain integral proteins with numerous functions such as movement of objects into and out of the cells and facilitating the production of energy for the cells. 
         [0007]    This cell membrane contains the genetic information for the cell found in the form of DNA, and contains many nutrients and structural building blocks in an aqueous, or liquid, environment. The cell wall, and specifically the bacterial membrane, are believed to be organized in a fluid mosaic model comprised of phospholipids, proteins, and other cell structures that are dynamic and constantly undergoing alterations in the number of different proteins present and in the locations of these proteins. The physical structure of the membrane includes the phosphate ends of the molecular structures that are organized facing to the exterior and interior of the cell and are hydrophilic, while the fatty acids segments of the molecular structures are hydrophobic and are sandwiched in between the phosphate groups creating selective fluidity in the membrane that selectively transfers cell-sustaining moieties into and out of the cell. 
         [0008]    An accumulation of molecular nutrients within the boundaries of the cellular membrane creates a hypertonic environment that forms a higher concentration of molecules per volume of water than in the surrounding environment. In order for water and other nutrients to enter the cell, numerous molecule-specific passageways must exist to facilitate passage through the hydrophobic portions of the cellular membrane. These passageways are proteins called transport proteins and are imperative in creating fluidic balance between the cell and its surrounding environment. The physical structure created by the interactions of the amino acids constituting the protein regulates the entrance and exit of molecules into the cell. A passage way is formed within the protein structure that allows the passage of specific molecules the particular protein is configured to transport. 
         [0009]    Altering the external environment to the cell to mimic conditions under which the external environment has higher molecular concentrations than the internal environment of the cell alters the flow of water and other molecules into and out of the cell and ultimately destroys the cellular membrane, resulting in death of the pathogen cell. 
         [0010]    Aquaporins, for example, are a class of proteins that transport water molecules across membranes. The bond interactions of the amino acids create a pore in the protein. Such a pore embedded in the membrane as part of the fluid mosaic model facilitates transfer of water molecules into and out of the cell. 
       SUMMARY OF THE INVENTION 
       [0011]    In accordance with the present invention, it has been determined that alterations in pH, temperature, and pressure can destroy bond interactions which distorts this opening, allowing either more or less water to enter, depending on the desired effect. By manipulating pressure, temperature, and pH independently, or in combination with each other, the bonding properties that define the structure of the protein are disrupted, which alters the physical structure of the protein, and can render it inactive, or more appropriately, denatured. 
         [0012]    In accordance with the present invention, fish, poultry and meat products are initially processed through a series of diverse environments including vacuum and pressure conditions applied to processing fluids at various temperatures to significantly diminish the internal and surface concentrations of pathogens. Reduced levels of residual pathogens thus achieved delay proliferation of microorganisms and the resultant decay of the product at elevated temperatures. The resultant product exhibits extended shelf life, even after freezing and thawing, and also exhibits appealing marketability for enhanced product sales with reduced losses over longer processing, distribution and retailing intervals. 
         [0013]    Protein denaturing and cellular death of the bacteria are achieved while maintaining the integrity of the product. In one embodiment, various processing in three vessels subject the product and contaminates to variations in pH, temperature, and pressure as the product passes through each vessel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a pictorial illustration of an assembly of successive environments for processing product in accordance with the present invention; 
           [0015]      FIG. 2  is a plan view of a vessel of  FIG. 1 ; 
           [0016]      FIG. 3  is a plan view of the product-tumbling conveyor in the assembly of  FIG. 1 ; 
           [0017]      FIGS. 4 and 5  are perspective views of transfer conduits in the assembly of  FIG. 1 ; 
           [0018]      FIGS. 6   a ,  6   b  comprise a flow chart illustrating the processes of the present invention; and 
           [0019]      FIGS. 7-12  are graphs illustrating results of processing according to the present invention to reduce various pathogens in comparison with results of conventional processing. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    Referring now to  FIG. 1  there is shown a pictorial illustration of a product processing line and process vessels  9 ,  11 ,  13  containing variable environments through which product  15  is processed according to the present invention. This succession of vessels is assembled to receive fish, poultry or meat products  15  previously cleaned, scaled, filleted, or otherwise prepared or dressed from the initial natural state following catch or slaughter of the host animal. Such preparations of the product  15  may be performed at work stations (not shown) arrayed along a length of a conveyor  17  for feeding into a tumbling conveyor  19 , as described later herein with reference to  FIGS. 3   a ,  3   b . The product  15  is randomly tumbled and washed along conveyor  19  in preparation for entry into the first processing vessel  9  through open inlet valve  21 , with the downstream outlet valve  23  closed. Each of the pressure vessels  9 ,  11 ,  13 , as illustrated in  FIG. 2 , is configured generally as a cylindrical chamber that includes an air vent  25  for normalizing internal vessel pressure, and a vacuum line  27  for reducing internal pressure in the associated vessel. In addition, each vessel includes a fill line  29  for supplying sanitizing fluid and a pressurizing line  31  for increasing the internal pressure within the associated vessel. And, each vessel includes one or more drain lines  33  for transferring sanitizing liquid from the associated vessel. Each vessel is arranged in fluid communication with a successive vessel through closed transfer conduits  35 ,  37  and inlet and outlet valves  21 ,  23  that may be selectively opened to transfer product  15  therethrough, and closed to establish and maintain a pressurizable environment within the respective vessels. 
         [0021]    The valves  21 ,  23  may include a sliding gate or rotating ball, or the like, to selectively open or close the transfer conduits  35 ,  37  between vessels  9 ,  11 ,  13 . Thus, product  15  may proceed along the conveyors  17 ,  19  and through the open valve  21  into the first processing vessel  9 . 
         [0022]    Following the loading of product  15  into the first vessel  9 , the inlet valve  21  is closed and the loaded products  15  are initially immersed in an aqueous sanitizing solution, for example, a peroxygen compound (e.g., peroxyacetic acid, Octanoic acid and hydrogen peroxide and approximately 99% water) as an anti-microbial agent that is colorless, odorless and tasteless. The sanitizing solution, at a concentration of about 100 parts per million, is supplied to the vessel  9  and circulated between fill and drain lines  29 ,  33  through pumps, filters, and cooling equipment (not shown) at a temperature of about 32°-35° F. to effectively thermally shock the loaded product  15 . During this interval, the fluid pressure is increased to a level of about 980 pounds per square inch (gage pressure). Then, the fluid pressure is reduced and vacuum is drawn down below ambient to about 2.4 pounds per square inch. Selected levels of fluid pressure and vacuum may be achieved by pumps (not shown) that connect to the vessel via pressure or vacuum connections  27 ,  31 . The cycles of pressurization and vacuum may extend for about 55 seconds and may be repeated one or more times (typically 5 times for  Gadus.Macrocephalus , or Cod) depending upon the type of product  15 . This procedure is believed to apply hypo- and hyper-tonic osmotic processes to the fish, poultry or meat tissues of product  15  to alter the functioning of the cell walls and cell-wall proteins in a manner as previously discussed herein. This procedure is believed to eliminate contact Prokaryotic Cells via lysis prepare the product  15  for the next processing environment. The total dwell time in the initial environment within vessel  9  over the interval of the selected number of fluid pressure and vacuum cycles ensures substantial reductions in bacterial concentrations at logarithmic rates per unit time of immersion and pressure-vacuum cycles, as is commonly understood in the food processing industry. Product  15  of larger unit volumes greater than a cut size of about 10 pounds may require additional immersion time to accomplish comparable concomitant reductions in bacterial concentrations. The fluid pressure in the vessel  9  is then relieved or normalized to ambient condition through the valved air vent  25  after the initial phase of processing in vessel  9 . 
         [0023]    By this processing, the product is subjected to a low pH or high peroxygen concentration environment due to the addition of the peroxygen compound, a decreased temperature gradient, and fluctuating fluid pressure and vacuum cycles over a specified cycling period of approximately five minutes. This process performs a primary contact kill of microbes on the surface of the product. The pressurized environment creates an apparent high concentration of hydrogen ions donated by the peroxygen compound on the exterior of the cell, and this increases movement of molecules into the cell. The cell wall itself is weakened from the disruption of peptide bonds by adding oxygen donated by the peroxygen compound across the bond. By cleaving the peptide bonds that hold the crosslinkers of the sugar molecules together (that is, either the tetrapeptide in gram negative bacteria or the tetrapeptide and the pentaglycine crosslinkers in gram positive bacteria) the cell wall is severely weakened. The addition of osmotic pressure and changes in pH, altering protein structures in the membranes, act in addition to the weakened cell wall, thereby increasing fluidity of the protein transfer channels to result in bacterial cell lysis at a substantially more effective level. 
         [0024]    Product  15  in vessel  9  is next transported from the vessel  9  to the second processing vessel  11  via transfer conduit  35  and open outlet valve  23  and open inlet valve  21 , with the downstream outlet valve  23  of vessel  11  closed. The transfer conduit  35  is described later herein with reference to  FIG. 4 . After the quantity of product  15  is loaded into the second processing vessel  11 , the inlet valve  21  is closed to confine the product  15  within the vessel  11 , and a sanitizing agent such as described previously at a concentration of about 140 parts per million is introduced into and circulated within the vessel  11  between fill and drain lines  29 ,  33  at an elevated temperature (for example, of about 72° F. for  Gadus.Macrocephalus , or Cod). The internal fluid pressure is then elevated to a pressure above ambient to about 980 psi (gage) and the processing liquid is circulated in vessel  11  in a manner as previously described herein between fill and drain lines  29 ,  33 . Then, the internal fluid pressure in vessel  10  is reduced and vacuum is drawn down below ambient to about 2.4 pounds per square inch. Such fluid pressure and vacuum cycling may extend for about 40 seconds and may proceed one or more times (typically 5 times for  Gadus.macrocephalus , or Cod), depending upon the type of product  15 , at substantially the temperature of liquid in vessel  11 . This intermediate processing in vessel  11  is believed to cause an expansion of the cellular matrix and an increased osmotic effect with concomitant increased rate of penetration of sanitizing solution through the Eukaryotic cellular walls and into the interior portions of the cells where the anti-microbial liquid agent can more effectively destroy pathogens within the cell matrix of the product  15 . At the end of the processing interval, the internal fluid pressure in vessel  11  is normalized through the valved air vent  25  to ambient pressure, and the drain  33  is opened to release the volume of processing liquid. The downstream outlet valve  25  is opened to transfer the product  15  through the transfer conduit  37 , to the third processing vessel  13 . A state of expanded cellular matrix in the product  13  is thus achieved and maintained while passing through the transfer conduits  37  and open inlet valve  21  to the third vessel  13 . 
         [0025]    In the second vessel  11 , the elevated temperature and fluctuating fluid pressure and vacuum cycles infuse the organic peroxygen compound into the cellular matrix of the product via expansions created in the matrix of the product itself by the push and pull effect created by the cyclic exposure to fluid pressure and vacuum to facilitate the action of the peroxygen compound on the bacterial cells. The contrasting molecule concentrations in the environment surrounding the cells and in the cells internal environment influences the movement of molecules into the cell resulting in cytoplasmic membrane disruption and protein denaturing. This step effectively destroys bacteria on the interior tissues of the product in addition to the surface kill experienced in the first vessel, while maintaining the integrity of product itself. In the second vessel the product is exposed to cycles of oscillating fluid pressure and vacuum that expand the cellular matrix of the tissues, allowing for infusion of the organic peroxygen compound on the surface and into the interior of the product. This is believed to disrupt the hypo- and hypertonic dynamics and create a push and pull effect on the cell matrix of the product. The peroxygen compound introduces oxygen, which carries a negative charge and which attracts hydrogen ions carrying a positive charge. These ions are involved in bonding interactions of the cell wall and proteins to disrupt the physical structure. To facilitate the expulsion of the infused solutions, the third vessel  13  uses highly diluted, super-chilled sanitizing solution, for example, of the type previously described, with vacuum cycles to expel the unwanted fluids from the cellular matrix of the product and to lower its total fluid volume. 
         [0026]    In similar manner as previously described herein, product  15  is then transported via the transfer conduit  37 , as described later herein with reference to  FIG. 5 , and open inlet value  21  to the third processing vessel  13  for loading therein, with the downstream outlet valve  23  closed. After a sufficient quantity of product is loaded into the vessel  13 , the upstream inlet valve  21  is closed to confine the product  15  within the vessel  13 , and sanitizing solution such as previously described herein at a concentration of about 70 parts per million is introduced into and circulated within the vessel  13  at reduced temperature of about 31-33° F. The internal fluid pressure is then reduced or ramped down through the vacuum line  27  to a level below ambient pressure of about 2.4 pounds per square inch over an interval of about 4 minutes. The vacuum level is then further reduced to about 0.000147 pounds per square inch for an interval of about 1.5 minutes, with the sanitizing solution drained from the vessel  13  through the drain lines  29 ,  33  in the manner as previously described herein. 
         [0027]    This final processing in vessel  13  (prior to packaging operations) is believed to cause a contraction of the cellular matrix and an expulsion of undesirable fluids from the tissue in product  15 , as well as creating a ‘dormancy” state of cellular respiration in preparation for final packaging. At the end of this final processing interval, the internal fluid pressure is normalized to ambient pressure via the valved air vent  25 . The drain lines  33  are opened to release the volume of super chilled sanitizing solution, and the downstream outlet valve  23  is opened to release product  15  through the transfer conduit  39  in a fluid movement out of the vessel for packaging in suitable manner. A nearly dormant and contracted cellular matrix state in the product  15  is thus achieved and maintained in preparation for the packaging. The cellular matrix begins to expand to its initial state (e.g., as at the beginning of the process) from the near-dormant respiration rate that was achieved through the previous processing, and this promotes drying of the exterior of the product  15  and reduces the growth of pathogens which breed in oxygen and moisture. 
         [0028]    Processing in this manner through vessels  9 ,  11 ,  13  sanitizes the product without altering the texture, appearance, color or flavor profile, and a form of atmosphere-modifying packaging is utilized to control gas levels and packaging that occurs within an ultra low-particulate filtered environment to eliminate cross-contamination of the sanitized product. The final product is encapsulated or otherwise packaged in a sterile packaging bag or wrapping material with a specific oxygen transmission rate, or OTR of about 30. (OTR is a measurement of how many cubic centimeters of oxygen pass through a 100 square inch portion of wrapping material during a 24 hour period at 23° C.). This step controls the concentrations of oxygen and carbon dioxide inside the final packaging so that metabolic activities, the functions necessary for the bacteria to live, are reduced to ensure that any organisms that survive the processing are not able to replicate due to lack of oxygen for metabolism. Heat accumulation in the packaging is greatly reduced because of the controlled release of gases, thereby creating a slow bacterial growth accumulation or extended growth curve. This type of packaging extends the shelf life of the product due to the inhibition of bacterial growth and lack of cross-contamination. 
         [0029]    As illustrated in the graphs of  FIGS. 7-12 , the concentrations  71  of various identified bacterial pathogens in samples of  Gadus.Macrocephalus  fish product  15  processed according to the present invention compare favorably after 3 or 4 days with significantly higher concentrations  73  of the various bacterial pathogens in such product processed in conventional manner. 
         [0030]    The pressure and vacuum ramp up and ramp down intervals to respective fluid pressure and vacuum levels in each of the vessels  9 ,  11 ,  13  are selected to maximally achieve reduced levels of pathogens in the type of product  15  being processed. Examples of typical processing fluid pressure and vacuum levels and temperatures and cycles and times another product is set forth in the following tables. 
       In Vessel  9 : 
       [0031]      
         [0000]    
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                   
                 Vacuum 
                   
                   
                   
               
               
                   
                   
                   
                 Level 
                 Pressure/ 
                 Vacuum/ 
               
               
                   
                   
                 Dwell 
                 Below 
                 Vacuum/ 
                 Pressure 
               
               
                   
                 Pressure 
                 Time 
                 Ambient 
                 Dwell 
                 Cycles 
                 Temp. 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Pollock 
                 595 psi 
                 1:20 
                 2.4 psi 
                 1:00 
                 8 
                 34° F. 
               
               
                   
               
             
          
         
       
     
       In Vessel  11 : 
       [0032]      
         [0000]    
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                   
                 Vacuum 
                   
                   
                   
               
               
                   
                   
                   
                 Level 
                 Pressure/ 
                 Vacuum/ 
               
               
                   
                   
                 Dwell 
                 Below 
                 Vacuum/ 
                 Pressure 
               
               
                   
                 Pressure 
                 Time 
                 Ambient 
                 Dwell 
                 Cycles 
                 Temp. 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Pollock 
                 595 psi 
                 1:20 
                 2.4 psi 
                 1:00 
                 8 
                 69° F. 
               
               
                   
               
             
          
         
       
     
       In Vessel  13 : 
       [0033]      
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 First 
                   
                 Second 
                   
                   
               
               
                   
                 Vacuum 
                   
                 Vacuum 
                 Final 
               
               
                   
                 Level 
                   
                 Level 
                 Vacuum 
               
               
                   
                 Below 
                 Dwell 
                 Below 
                 Dwell 
               
               
                   
                 Ambient 
                 Time 
                 Ambient 
                 Time 
                 Temp. 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Pollock 
                 2.4 psi 
                 4:35 
                 .000147 psi 
                 1:20 
                 31.6° F. 
               
               
                   
               
             
          
         
       
     
         [0034]    Where desirable, product  15  emerging from the last processing vessel  13  may be quick frozen in conventional matter within a freeze-processing environment for transfer to the final packaging. Alternatively, product  15  emerging from the last processing vessel  13  may be transferred directly to the final packaging phase where frozen product is not desirable. The packaging environment may be maintained at about 33-35° F. via cooling and filtering equipment (not shown) to inhibit thawing of frozen product  15  transferred from a quick freeze environment while being wrapped and sealed or otherwise encapsulated for retail distribution under sustained freezing temperatures during transport and storage. Alternatively, product  15  transferred from vessel  13  in non-frozen but dormant state is maintained in such state during the brief interval while being wrapped and sealed or otherwise encapsulated for retail distribution under sustained near-freezing temperature and during transport and storage. 
         [0035]    Referring now to  FIG. 2  there is shown a plan view of typical vessels  9 ,  11 ,  13  of type that are assembled in the succession illustrated in  FIG. 1 . In one embodiment of the vessels  9 ,  11 ,  13 , the main chamber is substantially cylindrical with hemispherical or conical end segments, as desired to comply with facility layout restrictions, that are disposed eccentrically or angularly with the central cylindrical segment of the vessel and with the transfer-conduits  35 ,  37  at each end. The eccentric alignment of vessel  9 ,  11 ,  13  and transfer conduits  35 ,  37  establishes common alignment along the peripheral base  30  of mating interior surfaces to promote easy transfer of product  15  into and out of the vessel. Each vessel includes filler line  29  that includes a substantially horizontal conduit  32  positioned within and along a substantial length of the vessel. The horizontal conduit  32  includes orifices located along its length oriented generally downwardly and laterally to promote mixing and agitation of contents within the vessel in response to liquid supplied thereto under pressure. This assures complete filling of the vessel with liquid and product for processing as described herein. Such filler line  29  is assembled with pumps and filters and heating or cooling equipment (not shown) for collecting, filtering, processing and supplying liquid to the vessel at pressures relative to internal pressures and at appropriate product-processing temperatures, as previously described herein. 
         [0036]    Each vessel is also fitted with one or more drain lines  33  at the bottom of the vessel for removing liquids thereof to recycle during product processing, or to evacuate liquids from the vessel prior to transferring processed product therefrom. In addition, each vessel also includes pressure and vacuum lines  27 ,  31  and a pressure-release line  25  fitted to the top of the vessel for selectively pressurizing and evacuating the vessel during product processing in the manner as previously described herein. Flanges  34  attached at each end of the vessels facilitate pressure-tight attachments to mating flanges on the valves  21 ,  23  that are disposed intermediate each of the assembled vessels  9 ,  11 ,  13 , as illustrated and described herein with reference to  FIG. 1 . A viewing port  36  containing a sight glass or window is fitted to each vessel near the top if so required to facilitate visualization of the agitation of product  15  and liquid within the vessel. Of course, the vessels  9 ,  11 ,  13  may be of different volumetric sizes, for example, to accommodate greater volumes of product  15  per processing cycle, or to accommodate processing of product  15  over different processing times per vessel. 
         [0037]    In another embodiment of the present invention, one or more of the vessels  9 ,  11 ,  13  may be substantially cylindrical and mated with end sections of selected configurations to accommodate facilities where space constrictions are not present. 
         [0038]    Referring now to  FIG. 3 , there is shown a side view of a tumble-style conveyor  19  that is positioned at the entrance to the first processing vessel  9  to receive unitized product  15  from conveyor  17 . Specifically, this conveyor  19  and conveyors  17  and  39  may be configured similarly to a conveyor, for example, as described in U.S. Pat. No. 6,050,391 with a plurality of spray nozzles  20  disposed above and below segments of the continuous belt  22  to wash and sanitize the upper and lower surfaces thereof with sanitizing solution supplied under pressure to the connecting conduits by pumping equipment  26 . 
         [0039]    The successive stages of the elevate-and-drop configuration of the serpentine-like path of the belt  22  promotes tumbling and thorough washing of product  15  dropped from an elevated portion to a lower portion of the belt  22  along its path of travel toward the inlet to the first processing vessel  9 . 
         [0040]    Referring now to  FIGS. 4 and 5 , there are shown perspective views of longer  35  and shorter  37  transfer conduits that are disposed between processing vessels  9 ,  11  and  11 ,  13 . In one embodiment of the shorter transfer conduit  37  as a generally semicircular conduit, an annulus-shaped conveyor system operating in folded, semi-circular configuration suffices to move product  15  from processing vessel  11  to processing vessel  13 . Similarly, in the longer transfer conduit  35 , such a semicircular conveyor system, or a linear conveyor system disposed between quarter-turn conveyor systems may suffice to move product  15  from processing vessel  9  to processing vessel  11 . Alternatively, adequate elevation of vessel  11  above vessel  13 , and elevation of vessel  9  above vessel  11  may promote gravity transfer of product  15  between vessels, aided by a flow of sanitizing solution exiting from a preceding vessel. 
         [0041]    Equipment for filtration, cooling or heating and pumping of the processing liquids, as well as for pressurizing vessels and refurbishing processing liquids may all be housed remotely from the processing of product  15  through the assembly of vessels  9 ,  11 ,  13  and may be piped and ducted thereto in order to preserve sanitary conditions and to avoid contaminants from machine-oriented sources. 
         [0042]    Referring now to the flow chart of  FIGS. 6   a ,  6   b , the processing of a product  15  starts with parcelizing  41  unit volumes of the product, for example, as fillets, steaks or poultry parts that are then transported  42  to and confined  43  within the first processing vessel  9 . Sanitizing solution of a type as previously described herein is then supplied  45  to and circulated within the first processing vessel  9  at a temperature near freezing for a first processing interval  47  during which internal fluid pressure is varied above and below ambient pressure one or more times, as previously described herein. 
         [0043]    At the conclusion of the first processing interval, the product  15  is transferred  48  through the valve in the transfer conduit  35  to the second processing vessel  11  for confinement  49  therein between closed valves. Sanitizing solution of a type as previously described herein is then supplied  51  to and circulated within the second processing vessel  11  at a temperature of about 72° F. for a second processing interval  53  during which internal fluid pressure is varied above and below ambient pressure one or more times, as previously described herein. 
         [0044]    At the conclusion of the second processing interval, the product  15  is transferred  54  through the valve in the transfer conduit  37  to the third processing vessel  13  for confinement  55  therein between closed valves. Sanitizing solution of a type as previous described herein is then supplied  57  to and circulated within the third processing vessel at a temperature near freezing for a third processing interval  59  during which internal pressures are reduced to vacuum levels below ambient pressure in manner as previously described herein. 
         [0045]    At the conclusion of the third processing interval, the product  15  is transferred  60  to a packaging environment  61  for sealed wrapping or other encapsulation in either quick frozen or non-frozen condition suitable, for example, for retail distribution. 
         [0046]    Therefore, animal products processed in accordance with the present invention exhibit a greatly reduced pathogen count with concomitant slower growth of bacteria and retardation of the KREBS cycle. The apparatus and processes of the present invention thus greatly reduce pathogenic contaminants that contribute to the deterioration of meat, poultry and fish products prepared for retail distribution, and thereby significantly increase retail shelf life of such products.