Packaging of Beef Loin Steaks in 75% O₂ plus 25% CO₂. I. Physical and Sensory Properties

U.S. Choice boneless beef strip loins from four suppliers were used to determine the effect of using previously vacuum-packaged beef subprimals and the effect of using subprimals at different storage intervals--0, 14 or 28 days--after arrival at our laboratory on the retail appearance of steaks packaged in 75% O₂ + 25% CO₂. After packaging, steaks were stored for 9 days in the dark in a 1 ± 1-C refrigerated cooler and displayed under 1030 lux of incandescent light in a retail case for 4 days at 2 ± 2 C. Selected subprimals were repackaged and held at 1 ± 1 C for 9 days in the dark and steaks were removed and packaged in polyvinyl chloride (PVC) film and displayed for 4 days to serve as display controls. With regard to surface discoloration, overall appearance and off-odor scores, modified gas atmosphere (MGA)-packaged steaks from strip loins fabricated at Day 0 were not different (P>.05) from PVC-packaged steaks, however, MGA-packaged steaks from strip loins fabricated at Day 14 or Day 28 were less desirable (P<.05) than PVC-packaged steaks or steaks that were MGA-packaged on Day 0. When comparisons of retail appearance characteristics were made among loins from different suppliers, the results were mixed; data from steaks that were MGA-packaged at Day 14 revealed (P<.05) differences among loins from different suppliers in surface discoloration and off-odor while data from steaks that were MGA-packaged at Day 28 revealed no (P>.05) differences among loins from different suppliers in surface discoloration or overall appearance. Data indicate that modified gas atmosphere packaging of beef loin steaks can be successful if very fresh subprimals are used; however, extended vacuum-storage of beef subprimals (14 or 28 days) did not provide raw material that was amenable to subsequent storage-display in modified gas atmosphere packages.