Effect of modified gaseous atmospheres on the biochemical and physical changes of packed meat during storage

Abstract

One hundred and forty beef cuts were vacuum packaged. Cuts were assigned to treatments which included vacuum packaging and vacuum packaging followed by subsequent injection with atmospheres of either 100% O₂, 100% Co₂ or 100% N₂. Cuts were then stored for periods of 7, 14, 21 or 28 days at 1-3 °C. At the termination of each storage period, data were collected for gas composition inside packages, weight loss, surface discoloration, pH, psychrotrophic and lacto-bacilli counts, and protein solubility. Data indicate that an atmosphere initially containing 100% CO₂ is a viable alternative to the use of vacuum packaging. Cuts stored in an atmosphere initially containing 100% CO₂ generally had lower microbial counts and les surface discoloration after 3 days of retail display than vacuum packaged cuts stored for the same period of time. Two disadvantages associated with packaging in a 100% CO₂ atmosphere, as compared to a vacuum packaging included: (1) a 4 hr bloom period was required after removal of cuts from a CO₂ atmosphere as compared to 1 hr for vacuum packaged cuts, and (2) the percentage weight loss was significantly higher for cuts stored in a 100% CO₂ atmosphere as compared to that for vacuum packaged cuts. Carbon dioxide may bind to proteins altering their ability to hold moisture, bloom rapidly and result in greater denaturation of the sarcoplasmic proteins as shown by loss of their solubility.