Process for the extension of microbial life and color life of fresh meat products

Abstract

The microbial life and color life of fresh meat products are extended by placing fresh meat in a tray, sealing the fresh meat in the tray in an atmosphere that excludes oxygen and contains carbon monoxide, and applying ionizing radiation to the tray containing the fresh meat. The color life of the fresh meat in the tray may be controlled (such as to be equal to or less than the microbial life) by employing a permeable element and an impermeable element to seal the fresh meat in the tray. The impermeable element is removed at a time after ionizing radiation has been applied, so that the atmosphere that excludes oxygen and contains carbon monoxide is exchanged for ambient atmosphere, resulting in predictable limiting of color life of the fresh meat.

1 . A method of providing fresh meat products, comprising: 
 placing fresh meat in a tray and sealing the fresh meat in the tray in an atmosphere that excludes oxygen and includes carbon monoxide; and    applying ionizing radiation to the tray containing the fresh meat.    
   
   
       2 . The method of  claim 1 , wherein the atmosphere that excludes oxygen further includes nitrogen and carbon dioxide.  
   
   
       3 . The method of  claim 2 , wherein the atmosphere that excludes oxygen consists of 70% nitrogen, 29.6% carbon dioxide and 0.4% carbon monoxide.  
   
   
       4 . The method of  claim 1 , wherein the step of applying ionizing radiation to the tray containing the fresh meat is performed in an environment that is controlled to exclude oxygen.  
   
   
       5 . The method of  claim 1 , further comprising: 
 unsealing the fresh meat in the tray in a retail environment after ionizing radiation has been applied.    
   
   
       6 . The method of  claim 5 , wherein the step of sealing the fresh meat in the tray comprises: 
 applying a permeable lid film to the tray to secure the fresh meat in the tray; and    enclosing the tray and permeable lid film in an impermeable bag.    
   
   
       7 . The method of  claim 6 , wherein the step of unsealing the fresh meat in the tray comprises: 
 removing the tray containing the fresh meat secured by the permeable lid film from the impermeable bag.    
   
   
       8 . The method of  claim 7 , wherein the permeable lid film has a permeability that provides a color life to the fresh meat in the tray that has a known correspondence to a microbial life of the fresh meat in the tray that is based on a dose of ionizing radiation applied to the fresh meat.  
   
   
       9 . The method of  claim 5 , wherein the step of sealing the fresh meat in the tray comprises: 
 applying a permeable lid film to the tray to secure the fresh meat in the tray; and    applying a peelable impermeable film over the permeable lid film.    
   
   
       10 . The method of  claim 9 , wherein the step of unsealing the fresh meat in the tray comprises: 
 peeling the impermeable film off of the permeable lid film.    
   
   
       11 . The method of  claim 10 , wherein the permeable lid film and the peelable impermeable film are multiple layers of a single film.  
   
   
       12 . The method of  claim 10 , further comprising: 
 applying a notification label on the peelable impermeable film to provide notification that the peelable impermeable film has not yet been removed.    
   
   
       13 . The method of  claim 10 , wherein the permeable lid film has a permeability that provides a color life to the fresh meat in the tray that has a known correspondence to a microbial life of the fresh meat in the tray that is based on a dose of ionizing radiation applied to the fresh meat.  
   
   
       14 . A method of providing fresh meat products, comprising 
 placing fresh meat in a tray and sealing the fresh meat in the tray in an atmosphere that excludes oxygen and includes carbon monoxide;    applying ionizing radiation to the tray containing the fresh meat; and    distributing the fresh meat in the tray for sale to consumers in a retail environment.    
   
   
       15 . The method of  claim 14 , further comprising: 
 unsealing the fresh meat in the tray in the retail environment after ionizing radiation has been applied.    
   
   
       16 . The method of  claim 15 , wherein the step of sealing the fresh meat in the tray comprises: 
 applying a permeable lid film to the tray to secure the fresh meat in the tray; and    providing an impermeable seal over the permeable lid film.    
   
   
       17 . The method of  claim 16 , wherein the step of unsealing the fresh meat in the tray comprises: 
 removing the impermeable seal over the permeable lid film.    
   
   
       18 . The method of  claim 17 , wherein the permeable lid film has a permeability that provides a color life to the fresh meat in the tray that has a known correspondence to a microbial life of the fresh meat in the tray that is based on a dose of ionizing radiation applied to the fresh meat.  
   
   
       19 . The method of  claim 16 , wherein the impermeable seal over the permeable lid film comprises an impermeable bag enclosing the tray and the permeable lid film.  
   
   
       20 . The method of  claim 16 , wherein the impermeable seal over the permeable lid film comprises a peelable impermeable film over the permeable lid film.