Abstract:
Processing apparatus and method for fish, poultry and meat products include multiple successive immersions in sanitizing solutions at different successive temperatures within controlled environments to promote low contamination during transfer of product between processing stations in preparation for encapsulation within a controlled environment confined within a barrier of composite sheet material that controls the transfer of selected gases therethrough.

Description:
RELATED CASES 
     The subject matter of this application is 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 subjects matter are incorporated herein by this reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to equipment and processes for processing and packaging fresh fish or poultry or meat to retard deterioration and promote extended shelf life. 
     BACKGROUND OF THE INVENTION 
     Fish, poultry and meat products 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 the product. Extended shelf lives for such 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 an iced or refrigerated environment, attributable to microorganisms present on the surface of the product as well as within the product that remain present from initial processing and that are capable of rapid proliferation 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. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, fish, poultry and meat products are initially processed through a series of diverse environments that tend to cycle the respiration rates of the product and significantly diminish the internal and surface concentrations of pathogens which affect decay of the product at elevated temperatures. The resultant product exhibits extended shelf life, even after freezing and thawing, and appealing marketability for enhanced product sales with reduced losses over longer processing, distribution and retailing intervals. 
    
    
     DESCRIPTION OF THE DRAWINGS: 
     FIG. 1 is a pictorial diagram of successive environments for processing product in accordance with the present invention; and 
     FIG. 2 is a flow chart illustrating the process of the present invention; and 
     FIG. 3 is a perspective view of a composite sheet material that is suitable for wrapping the processed product to selectively control the aspiration rate thereof. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIGS. 1 and 2, there are shown pictorial diagrams of a product processing line and process containing several environments through which product  13  is processed according to the present invention, as illustrated in the flow chart of FIG.  2 . Specifically, three successive environments  9 , 10 , 11  are assembled to receive fish, poultry or meat products  13  previously cleaned, scaled, filleted, or otherwise prepared or dressed from the initial natural state following catch or slaughter of the host animal. The first environment  9  includes a tank  15  containing a sanitizing solution of water and an anti-microbial agent such as peroxyacetic acid as a colorless, odorless, tasteless composition (commercially available as TSUNAMI 100) which is cooled to approximately 32°-35° F. and is circulated in the tank  15  at a concentration of about 85 parts per million parts water. The surrounding ambient conditions within environment  9  include air temperature at about 33°35° F. with relative humidity of about 98%. Product  13  is initially immersed  16  in the aqueous solution within tank  15  for about 1-3 minutes to effectively thermally shock the product, which is believed to elevate the cell respiration rate and prepare the product for the next processing environment. The dwell time of approximately 3 minutes ensures substantial reductions in surface bacterial concentrations at logarithmic rates per unit time of immersion, as is commonly known in the food processing industry. Products  13  of larger unit volumes greater than a cut size of about 10 pounds may require additional immersion time to accomplish comparable shock elevation of cell respiration rates and reductions in surface bacterial concentrations. 
     The product thus ‘shocked’ to a state of elevated cell respiration is then transferred  17  to the second environment  10  for immersion in a tank  19  containing an aqueous solution similar to the solution contained in tank  15  and that is circulating at a temperature of about 70°-105° F. The surrounding ambient conditions within environment  10  include air temperature at about 60°-95° F. with relative humidity of about 98%. It is believed that exposure of the product  13  to this sudden increase in temperature while at an elevated cell respiration rate expands the cell matrix and cell structure (vacuole) of the product analogous to opening up the pores of the product, and this facilitates increased penetration of the anti-microbial liquid agent into the cell matrix and cell structure (vacuole). This facilitates more thorough penetration of the product by the anti-microbial liquid agent in tank  19  which is thus rendered more effective in destroying pathogens within the cell matrix of the product  13 . The product  13  remains immersed in tank  19  for about 3-7 minutes (dependent in part upon cut size and batch size) to affect substantial reductions in both the internal pathogens and any remaining surface bacteria, at rates of diminishing concentrations that vary logarithmically with time, in a manner that is commonly known in the food processing industry. 
     The product  13  thus elevated in temperature and exhibiting enhanced absorption of the anti-microbial liquid agent in tank  19  is then transferred  21  to the third environment  11  for immersion in tank  23  containing an aqueous solution similar to the solution contained in tank  15  and that is circulating at a temperature of about 32°-35° F. The surrounding ambient conditions within environment  11  include air temperature of about 33°-35° F. with relative humidity of about 98%. This sudden decrease in temperature lowers the cell respiration rate of the product  13  to near dormancy state and promotes expulsion of absorbed liquids. The product  13  remains immersed in the tank  23  for approximately 5-10 minutes (dependent in part upon cut size and batch size) to ensure maximum expulsion of absorbed liquid and to effect substantial reductions in remaining bacterial concentrations at logarithmic rates per unit time, in a manner that is commonly known in the food processing industry. 
     The product is then removed from the environment  11  and is transported  25  either to quick-freezing environment  24 , or directly  28  to packaging facilities  26  within a cooled environment operating at a temperature of about 33° to 35° F. The product  13  thus transported (either via quick-freezing facility  24 , or directly) to the packaging facilities  26  thus remains in dormant (or frozen) state with substantially reduced levels of pathogens that can adversely affect the deterioration of the product  13  thus processed according to the present invention. 
     Referring still to FIG. 1, the temperature and humidity and air purity conditions within the environments  9 ,  10 ,  11 ,  26  are carefully controlled in response to the air conditioning equipment that is shown assembled above each environment. Specifically, cooling coils  31  are disposed with respect to modular blower or fan units  33  that may be assembled in modular arrays with respect to each environment  9 ,  10 ,  11  and packaging facility  26  to transfer cooled air from about the coils  31  through fine HEPA filters  35  to the respective environments. Specifically, the HEPA filters  35  are selected to restrict passage therethrough of particles and contaminants not greater than about 0.3 μ dimension, which therefore effectively filters out most, if not all, bacterial and pathogenic airborne contaminants. Such filters may also be assembled in modular arrays of about 2 foot by 4 foot panels for convenient cleaning and other servicing. Additionally, permeable curtains  37  such as overlapping vertical-hanging flexible strips of polyvinyl chloride (PVC) plastic material are disposed between environment  9 ,  10 ,  11  to facilitate maintaining temperature differentials in the adjacent environments  9 ,  10  and  10 ,  11 . 
     The product  13  is transported between environments by conveyor mechanisms  39  which retrieve product  13  from the immersion tank  15 ,  19 ,  23  in one environment for transport to the next environment. And, within each immersion tank  15 ,  19 ,  23 , the product  13  is kept moving through the immersion liquid composition by submerged conveyor mechanisms  41 . In this way, dwell times of product  13  within each tank  15 ,  19 ,  23  may be controlled by the rate of movement of the submerged conveyor mechanism from an entry location for incoming product  13  to an exit location for outgoing product  13 . And, the volumetric capacity of the tanks  15 ,  19 ,  23  may be sized proportionally to the dwell time of product  13  in each tank. Alternatively, the rate of product  13  entering environment  9  may be limited by the capacity of tank  23  that requires the longest product dwell time. In this way, continuous processing of product  13  may be accomplished without backup of product  13  into the slowest processing environment. 
     Where desirable, product  13  emerging  25  from the last processing environment  11  may be quick frozen in conventional manner within the freeze processing environment  24  for transfer to the final packaging phase in environment  26 . Alternatively, product  13  emerging from the last processing environment  11  may be transferred  25  directly to the final packaging phase where frozen product is not desirable. The packaging environment  26  is also maintained at about 33° F. and relative humidity of about 98% via the cooling coils  31  and blower or fan modules  33  and HEPA filters  35 , in the manner as previously described. In this environment, frozen product  13  transferred from the quick freeze environment  24  has only brief exposure time to non-freezing environment and has no opportunity to thaw while being wrapped and sealed or otherwise encapsulated  30  for retail distribution  32  under sustained freezing temperatures during transport and storage. Alternatively, product  13  transferred from environment  11  remains in non-frozen but dormant state during the brief interval while being wrapped and sealed or otherwise encapsulated  30  for retail distribution  32  under sustained near-freezing temperature during transport and storage. 
     Referring now to FIG. 3, there is shown a composite flexible sheet material  44  that is applied to product  13  following processing thereof as previously described in accordance with the present invention. The composite sheet material  44  is formed as bonded layers of polyethylene film  45  over polypropylene film  47 . This composite sheet material  44  is preferred as a sealing wrap about product  13  in frozen or dormant state for transportation and storage at the respective requisite temperatures during retail distribution because of the desirable gas permeability of such composite sheet material. Specifically, it has been discovered that such composite sheet material  44  transfers oxygen and carbon dioxide, among other gases, in a manner that retains an internal modified atmosphere of typically more than about 13% oxygen and less than about 5.5% carbon dioxide. The transmission rate of gases through the composite sheet material  44  may be altered by varying the thicknesses of the films  45 ,  47  that comprise the sheet material  44 . Specifically, it has been determined that, for a thickness of the polypropylene film  45  of about 1.0-3.0 mils, and a thickness of the polyethylene film  47  of about 0.5-3.0 mils, the composite sheet material is capable of transferring about 0.01-50 microliters of oxygen per hour at freezing or near-freezing temperatures (dependent upon headspace analysis determinations of the respiration rates of the individual products  13  and their associates cuts). Such permeability with respect to oxygen is believed to benefit the product  13  wrapped and sealed in such composite sheet material because of the resultant reductions in excess oxygen available to accelerate the known KREBS cycle (i.e., the breakdown of carbon compounds generated during the decaying process limits or retards the decaying process). As the KREBS cycle, or decay cycle, is a resultant of carbolic actions taking place on and within the product  13  to generate carbon compounds, the modified environment in which the product  13  is sealed is significantly altered, in that, the amount of bacteria/pathogens/particulates in the modified atmosphere is significantly less, and the ability to break down the complex carbon compounds via excess oxygen in the sealed environment is significantly reduced. 
     The resultant is a much slower growth of bacteria and a retarding of the KREBS cycle, and the apparatus and process of the present invention thus greatly reduce pathogenic contaminants that contribute to the deterioration of animal products prepared for retail distribution, and thereby significantly increase retail shelf life and sanitary packaging of such products.