The microbiology of beef steaks stored aerobically or anaerobically in vacuum pack films with different oxygen barrier properties

The objective of this study was to investigate bacterial growth on beef steaks stored under different atmospheric conditions (aerobic, anaerobic and low, medium and high barrier film vacuum packs) at 2 degrees C and temperature abuse (20 degrees C) conditions while monitoring changes in physicochemical and colour stability. At 2 degrees C, packaged steaks did not show significantly (p >= 0.05) reduced growth of mesophilic and psychrophilic total viable counts (TVCm and TVCp), Enterobacteriaceae or lactic acid bacteria populations compared to aerobically stored steaks but significantly (p < 0.05) less populations of Pseudomonas and Brochothrix thermosphacta were recorded in high barrier and anaerobic packaging. At 20 degrees C, medium, high barrier and anaerobic packaged steaks showed significantly (p < 0.05) less growth of TVCm, TVCp, Enterobacteriaceae, Pseudomonas spp. and B. thermosphacta compared to aerobically stored steaks. Overall, high barrier packaging with an oxygen transfer rate (OTR) of <3 cm(3)/m(2).day. bar and anaerobic storage both showed the greatest potential at reducing spoilage bacteria on beef (Pseudomonas and B. thermosphacta) while retaining the redness of the meat for the longest duration.