Carbon Monoxide Offers Improved Food Safety
Carbon monoxide as a packaging gas for fresh meat has stimulated a great deal of recent controversy. Critics have claimed that carbon monoxide packaging is an unsafe practice and is deceptive to consumers but, in reality, carbon monoxide provides a means to significantly improve product safety. Carbon monoxide was first approved by the Food and Drug Administration in 2002 as a Generally Recognized As Safe (GRAS) substance for fresh meat packaging. Yes, that's correct; carbon monoxide is considered GRAS...under the intended conditions of use. The latter phase is a typical qualification for GRAS substances. In fresh meat packaging, carbon monoxide is used at 0.4% of the package gases and represents absolutely no hazard at that concentration. What carbon monoxide contributes to meat is greatly improved color stability. A bright red color with carbon monoxide will last for 28-35 days in refrigerated storage instead of 5-14 days in other packaging systems. Critics have claimed that this is too long, possibly permitting spoilage while color still looks fresh. However, packages with carbon monoxide are labeled with "use by" and "freeze by" dates to provide consumers with a guide for avoiding spoilage.
What most people have missed in the arguements about carbon monoxide is that the improved color stability opens the door to antimicrobial treatments that will inhibit spoilage and pathogenic bacteria. There are two good examples. First, carbon dioxide gas is a good antimicrobial agent but at elevated concentration in meat packaging, will cause discoloration. When combined with carbon monoxide, no discoloration occurs. Research with fresh pork sausage has demonstrated that a high carbon dioxide concentration will prevent spoilage for about 21 days compared to about 6 days in conventional packaging. The second example where carbon monoxide permits better microbial control while retaining good color is with irradiated ground beef. Irradiated ground beef can be guaranteed to be free of pathogenic Escherichia coli O157:H7 and other pathogens, but irradiation also results in unattractive color darkening. With carbon monoxide, however, irradiated ground beef retains excellent color, is free of E. coli O157:H7 and has a 38-day shelf life instead of 3-7 days.
What's not to like about that?