Apparatus and method for extending shelf-life and prevention of discoloration of meat

Abstract

The current invention covers an improved meat-packaging procedure and machine for packaging meat cuts for long-term storage at temperatures of between 28° and 32° F. The process includes sealing meat cuts within a master bag containing oxygen scavenger materials capable of reducing the residual oxygen content of the atmosphere within the bag to 0 ppm within 24 hours of sealing. Gas is injected into the master bag to form a nitrogen-rich storage environment of at least 50% nitrogen. A small amount of carbon monoxide gas (0.1% to 5%) is preferred for the storage environment, as this helps to preserve the red coloration of meat under long-term storage conditions. The over-wrap of the meat trays can be perforated so that gas exchange occurs within the master bag between the interior and exterior of the meat tray to absorb the residual oxygen inside the meat trays. For meat trays containing meat with poor color stability, oxygen scavengers are preferably placed within the meat trays. For cuts with good color stability, the oxygen scavengers may be placed outside the meat trays. Meat can be stored by this system for up to 15 weeks and up to nine days of retail display life.

1 . A packaging system for minimizing meat discoloration comprising: 
 a stainless steel apparatus for preparing and packaging a master bag with low gas permeability containing one or more retail meat trays and including a conveyor system for transporting the retail meat trays through the apparatus, a folding box for constructing the master bag from material fed from a film pulley system connected to a roller feed, said master bag constructed by using a heat sealing mechanism to seal the sides of the film material forming a low gas permeable master bag;    a gas injected into the master bag from a gas supply system coupled to said apparatus before sealing said master bag after oxygenated air is flushed from the bag, said oxygenated air flushed from said bag using an oxygen-free gas mixture comprised of at least 50% inert gas to achieve an initial master bag atmosphere after sealing of less than or equal to 5% residual oxygen;    the retail meat tray comprising a tray with an oxygen scavenger sachet and an absorbent pad over wrapped with a gas permeable plastic-based film, said oxygen scavenger sachet containing an iron-based oxygen absorbing material self-activated in an atmosphere of greater than 70% relative humidity, and said over-wrap film permeable to allow atmosphere exchange between the interior and the exterior of the retail meat tray.    
     
     
         2 . The packaging system for minimizing meat discoloration of  claim 1 , wherein the oxygen scavenger sachet comprises: 
 a porous bag with an active surface area of between 4 to 64 square inches and porosity levels ranging from 20 to 120 gurly per second;    chemical granules ranging from 0.001 mm to 1.5 mm in diameter; and    a total weight of absorbing chemical of between 1 gram to 300 grams.    
     
     
         3 . The packaging system for minimizing meat discoloration of  claim 2 , wherein the chemical granules comprise: 
 less than 25% iron;    less than 35% carbon;    less than 20% vermiculite;    less than 10% de-ionized water; and    less than 10% NaCl salt.    
     
     
         4 . The packaging system for minimizing meat discoloration of  claim 3 , wherein the chemical granules comprise less than 10% zeolites.  
     
     
         5 . The packaging system for minimizing meat discoloration of  claim 1 , further comprising: 
 one or more oxygen scavengers positioned exterior to the retail trays within the master bag.    
     
     
         6 . The packaging system for minimizing meat discoloration of  claim 1 , wherein all the oxygen scavenger sachets sealed within the master bag obtain an absorption capacity of between 10 mL and 1000 mL per pound of meat.  
     
     
         7 . The packaging system for minimizing meat discoloration of  claim 1 , wherein all the oxygen scavenger sachets sealed inside the master bag exhibit an oxygen absorption capacity sufficient to reduce the oxygen half-life within the master bag to two hours or less.  
     
     
         8 . The packaging system for minimizing meat discoloration of  claim 1 , wherein the injected gas comprises nitrogen as the inert gas.  
     
     
         9 . The packaging system for minimizing meat discoloration of  claim 1 , wherein the injected gas comprises 5% or less of carbon monoxide.  
     
     
         10 . The packaging system for minimizing meat discoloration of  claim 1 , wherein the injected gas comprises: 
 greater than 50% inert gas;    5% or less carbon monoxide; and    carbon dioxide.    
     
     
         11 . An apparatus for packaging meat for long-term storage, comprising: 
 a conveyor system for transporting meat cuts, inside or outside of a retail meat tray, through the apparatus;    a film pulley feed system unrolling master bag material from a roller feed system into a folding box, said folding box operating to positioning one or more meat cuts within said master bag for packaging, said material exhibiting low gas permeability to oxygen;    a mechanism for flushing oxygenated air from the master bag using a gas mixture comprised of greater than or equal to 50% inert gas and less than or equal to 5% carbon monoxide to obtain an initial atmosphere containing less than 5% residual oxygen, said gas mixture flow into the apparatus controlled using a valve and supplied from at least one gas supply line coupled to a storage tank;    a reciprocating seal mechanism utilizing a specified dwell time, speed, pressure, and temperature to seal said master bag, said master bag including oxygen scavengers, located inside and/or outside a meat tray, for absorbing the residual oxygen in the initial atmosphere to obtain a zero oxygen storage atmosphere within 24 hours after sealing said master bag; and    a computer control system to control speed of the conveyor and heat sealing speed of the master bag.    
     
     
         12 . The apparatus for packaging meat for long-term storage of  claim 11 , further comprising: 
 a gas mixture for injecting into the master bag comprising between 0.1% and 5% carbon monoxide, between 35% and 39% carbon dioxide, and between 50% and 64.9% nitrogen.    
     
     
         13 . The apparatus for packaging meat for long-term storage of  claim 11 , further comprising: 
 a gas mixture for injecting into the master bag comprising between 0.1% and 5% carbon monoxide and between 50% and 99.9% nitrogen.    
     
     
         14 . The apparatus for packaging meat for long-term storage of  claim 11 , wherein the roller feed system comprises a plurality of formed master bags wrapped around a roller connected by perforations for easy separation and feeding into the folding box.  
     
     
         15 . The apparatus for packaging meat for long-term storage of  claim 11 , wherein the roller feed system comprises wrapped bag material on a roller fed into the folding box for heat-sealing the sides to form the master bag.  
     
     
         16 . A method for packaging meat for long-term storage before display to minimize meat discoloration, comprising the steps of: 
 packing a master bag with one or more retail meat trays or a primal or sub-primal cut of meat, said master bag constructed of a material exhibiting gas permeability for oxygen of less than 10 mL/m 2 /24 hours at 23° C.;    packaging said master bag using an apparatus constructed of stainless steel and including a conveyor system for transporting the retail meat trays or cuts of meat through the apparatus, a folding box for constructing the master bag from material fed from a film pulley system connected to a roller feed, and said master bag constructed by using a heat sealing mechanism to seal the sides of the feed material using said folding box;    flushing said master bag with a non-oxygen gas to reduce the residual oxygen level within said master bag to 5% or less and injecting an oxygen-free gas mixture containing carbon monoxide into the bag prior to sealing said master bag with a reciprocating heat-sealing mechanism;    packing within said master bag oxygen scavenger material self-activated in an atmosphere of greater than 70% relative humidity in sufficient quantity to reduce the oxygen half-life within said master bag to two hours or less after heat-sealing and obtain a zero oxygen storage atmosphere within 24 hours of sealing said master bag and able to function at a temperature range between 28° and 40° F.;    storing said master bag at a temperature of between 28° and 32° F.; and    transporting said master bag from a storage location to a retail sale location for display of said meat.    
     
     
         17 . The method for packaging meat for long-term storage before display to minimize meat discoloration of  claim 16 , further comprising the steps of: 
 packing retail cuts of meat in a retail meat tray consisting of a tray with an oxygen scavenger sachet and an absorbent pad overwrapped with a gas permeable plastic-based film perforated with one or more holes, said oxygen scavenger sachet containing an iron-based oxygen absorbing material and comprised of a porous material.    
     
     
         18 . The method for packaging meat for long-term storage before display to minimize meat discoloration of  claim 16 , further comprising the step of: 
 injecting a gas mixture into the master bag comprised of between 0.1% and 5% carbon monoxide and between 50% and 99.9% nitrogen.    
     
     
         19 . The method for packaging meat for long-term storage before display to minimize meat discoloration of  claim 16 , further comprising the step of: 
 providing oxygen scavengers sealed inside the master bag with a total absorption capacity of between 10 mL and 1000 mL of oxygen per pound of sealed meat inside the master bag.    
     
     
         20 . The method for packaging meat for long-term storage before display to minimize meat discoloration of  claim 19 , wherein the oxygen scavenger material comprises: 
 between 15% to 20% iron;    between 20% to 25% carbon;    between 10% and 15% vermiculite;    between 5% and 10% de-ionized water;    between 5% and 10% NaCl salt; and    between 0% and 10% zeolites.    
     
     
         21 . A method for packaging meat in a zero-oxygen storage environment, comprising: 
 packaging meat cuts on meat tray having a gas-impermeable film sealed over the top of the meat tray;    sealing said meat tray in a high nitrogen gas rich environment minimizing trapped oxygen to no more than 5% residual oxygen, over wrapping said meat tray within said gas environment with said gas-impermeable film to form an gas-tight seal using an apparatus;    sealing within said meat tray an oxygen scavenger for absorbing residual oxygen with an absorption capacity of between 10 mL and 1000 mL per pound of meat sealed within the meat tray and sufficient for a residual oxygen half-life of less than or equal to 2.0 hours that obtains a zero-oxygen storage environment within 24 hours of sealing;    said apparatus including a conveyor system for transporting the meat trays through the apparatus and a feeding system feeding the gas-impermeable onto a mechanism over wrapping the film over said meat tray and forming a gas-tight seal barring exchange of gas between the interior of said sealed tray and the exterior; and    storing said meat tray at a temperature of between 28°-32° F.    
     
     
         22 . The method for packaging meat in a zero-oxygen storage environment of  claim 21 , wherein the meat tray further comprises an absorbent pad sealed within.  
     
     
         23 . The method for packaging meat in a zero-oxygen storage environment of  claim 21 , wherein the nitrogen gas rich environment is 100% nitrogen.  
     
     
         24 . The method for packaging meat in a zero-oxygen storage environment of  claim 21 , wherein the nitrogen gas rich environment comprises: 
 at least 50% nitrogen;    between 0.1% and 5% carbon monoxide; and    carbon dioxide.