MODIFIED GAS ATMOSPHERES AND CHANGES IN BEEF DURING STORAGE

Beef steaks (n = 140) were assigned to treatments which included vacuum packaging and vacuum packaging followed by subsequent injection with gas atmospheres of either 100% O2, 100% CO2 or 100% N, Steaks 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 which included gas composition inside packages, percentage weight loss, surface discoloration, pH, psychrotrophic microbial counts and protein solubility. An atmosphere initially containing 100% CO2 appears to be a viable alternative to the use of vacuum packaging. After 3 days of retail display, steaks stored in an atmosphere initially containing 100% CO2 generally had lower psychrotrophic counts and less surface discoloration than steaks which were initially stored in vacuum packages. CO2 may bind to meat proteins decreasing their ability to hold moisture and to bloom rapidly. The use of a 100% N2 atmosphere does not seem useful except for its ability to minimize weight losses. Copyright © 1979, Wiley Blackwell. All rights reserved