Changing consumer demographics, coupled with new regulatory pressures and food safety concerns in the 1990s, drove processors and retailers to experiment with case-ready meat products. These products are cut into consumer-ready portions at federally inspected facilities, packaged and typically sold under brand names that consumers can seek or reject when making purchasing decisions.
The shift to case-ready made sense. The consumer of the ’90s sought convenient cuts that were always available. At the same time, in the face of unparalleled food safety pressures and high profile recalls and foodborne illness outbreaks, some retailers preferred to shift processing and handling to a centralized location where products could be cut, processed and packaged in a more controlled environment.
This concept was not new—the poultry industry has sold prepackaged and branded chicken in increasing volumes throughout the 1990s. Chicken maintained essentially the same color throughout its shelf life—a fact that made it ideal for case-ready. By 2002, 83 percent of chicken was sold case-ready, and by 2004, that number had climbed to 95 percent. By contrast, only 23 percent of beef and 66 percent of ground beef products were sold case-ready in 2004.
But the “will” was there. case-ready offered an array of other benefits—like preventing out of stocks. Research showed that case-ready meat products were out of stock far less often than store wrapped packages because these products facilitated better inventory management.
The presence of myoglobin in red meat, however, made case-ready packaging more technically challenging for beef and pork products. Historically, red meat products were cut or ground in the retail store and packaged on styrofoam trays with oxygen permeable films that allowed the bright red “bloom” that came from exposing these meat cuts to oxygen. Consumers came to associate this cherry red color with freshness. Processors and retailers rued the fact that the very contact with oxygen that gave meat the impression of “freshness” also caused it to degrade quickly due to oxidation. Red quickly turned to brown, meat flavor degraded and the product could not be marketed within a relatively short period of time.
Attempts to use vacuum packaging as a retail display technique to lengthen shelf life presented huge obstacles. Even though the vast majority of wholesale primals of beef and pork has been packaged and distributed in large vacuum bags for decades, without oxygen in the retail display package, meat products appeared in their true state: purple. Consumers expect to see red, and they mistakenly equate a red color with freshness. Although vacuum packaging of retail case-ready may be the most effective and cost efficient method, the package generally does not hold appeal for consumers.
High oxygen modified atmosphere packaging (MAP) offered consumers the color they expected and offered retailers some of the inventory control benefits of case-ready systems. Consumers also could choose the brands they prefer. However, the presence of oxygen in the MAP packaging still delivered a shorter shelf life than retailers would otherwise like due to the degradative effects of high oxygen concentrations in meat products. Antioxidant ingredients, such as rosemary extracts, were added in some cases to extend shelf life of products packaged in high oxygen for a few extra days.
Then, U.S. meat processors took their cue from Norway, where researchers found that by adding minute amounts of carbon monoxide into the gas mix in a low-oxygen modified atmosphere package, they could not only offer the extended shelf life that comes with low-oxygen modified atmosphere packaged meat, but also prevent the oxidative processes that result in off-flavors, off-odors and browning that ordinarily occur. When meat turns brown, flavor also is lost. Thus, by preventing oxidation, meat’s fresh flavor is maintained longer—a distinct benefit to the consumer.
Research has shown that this system could offer shelf lives that are similar to vacuum packaged products and higher than those of high oxygen packaged products. Research also shows that if temperature abuse occurs, while the meat would maintain its red color, other obvious signs of spoilage would make it nearly impossible for consumers to eat the product. Chief among these signs: a bulging package, a slimy appearance and an unmistakable odor associated with bacterial growth.
Only later in June 2006 would Texas Tech University researchers report that low-oxygen packaging MAP systems with CO could inhibit the growth of pathogens that were deliberately inoculated for research purposes. The lower the load of pathogens, the less risk there is to the public health if the product is undercooked or mishandled.
How It Works
Red meat contains the pigment myoglobin. In the absence of oxygen, myoglobin is in the “deoxymyoglobin” state (without oxygen) and is naturally “purple.” When oxygen is exposed, it becomes oxymyoglobin and develops a red color. Over time, a continual exposure to oxygen diminishes the ability of the meat to maintain the oxymyoglobin and the majority of the meat pigment will convert to metmymyoglobin which has a characteristic brown color.
When meat is exposed to small amounts of carbon monoxide, the carboxymyoglobin pigment is formed. This pigment is more stable than oxymyoglobin, and it has a red appearance that is virtually indistinguishable from oxymyoglobin to the naked eye, as well as to more sensitive spectrophotometric methods. By using CO in a modified atmosphere, the need for oxygen to achieve a red color is eliminated, thus the opportunity to eliminate the detrimental product effects that oxygen imparts to the product. Adding small amounts of CO will not convert brown meat back to red, but it will maintain the red color that is present when the product is packaged in the modified atmosphere.
IPE Case Ready MAP
IPE’s case ready product includes a barrier tray and top lidding film solution – maximizing product appeal and attractiveness at the retail store.