Centralized packaging of retail meat cuts: A review

Centralized packaging of retail meat cuts is growing more popular because o f its economies and potential to maintain quality, enhance safety, and exte nd the shelf life of fresh meat. Requirements for optimizing shelf life of centrally prepared retail cuts for periods up to 15 weeks are slightly diff erent from those needed to extend the shelf life of fresh, chilled meat. Ch illed meat primarily deteriorate at the cut or uncut muscle surface. In lon g-term storage, primal cuts are placed in an atmosphere saturated with carb on dioxide and containing very low residual oxygen. These cuts are held at -1.5 +/- 0.5 degrees C. When the meat is removed, it is fabricated into ret ail or food service cuts. New fresh surfaces are created in the process, re vitalizing the meat's appearance. After being prepared for retail display, the meat normally has four more days of shelf life. Depending on the meat s pecies, shelf life is usually limited by development of undesirable organol eptic changes, usually defects in color, which are independent of microbial presence. The microbes consist of a lactic acid bacterial population that maximizes under storage conditions at about 10(8) CFU/cm(2) well before she lf life ends. Circumstances are different with centralized distribution of retail-ready fresh meat. The wholesale storage period following initial pac kaging of the retail cuts is about 20 to 30 days. Prepared products must wi thstand retail display for up to 2 days without further manipulation of pac kage contents. Retail packages are simply moved from their storage containe r (usually a unit or overwrap containing a modified atmosphere) to retail d isplay, where desirable meat color develops upon exposure to air. Three gas atmospheres have some potential to satisfy storage needs for centralized d istribution of retail-ready packages: 100% CO2, 100% N-2, of 70% N-2 + 30% CO2. Shelf life is limited by undesirable changes in surfaces exposed at in itial packaging, caused by growth of psychrotrophic bacteria. If 100% CO2 i s used, these are all Lactic acid bacteria (LAB). Therefore, initial bacter ial numbers on the meat and storage temperature become critical to success. The most attractive storage option is 100% CO2 used at -1.5 +/- 0.5 degree s C. This review presents the reason for that recommendation, along with ba sic concepts of meat chemistry, a discussion of modified atmosphere packagi ng, meat microbiology, and current results with simulated centralized packa ging of retail-ready meats.