The Effect of Different Packaging Systems on the Shelf Life of Refrigerated Ground Beef

The aim of this study was to investigate the effects of different packaging systems on the shelf life of refrigerated ground beef. The ground beef samples were packaged as follows: AA (100% ambient air), 90O(2):10CO(2) (90% O(2) and 10% CO(2)), 80O(2):20CO(2) (80% O(2) and 20% CO(2)), 70O(2):30CO(2) (70% O(2) and 30% CO(2)), 60O(2):40CO(2) (60% O(2) and 40% CO(2)), 50O(2):50CO(2) (50% O(2) and 50% CO(2)), 100O(2) (100% O(2)), and VP (vacuum packaging). All treatments were analyzed daily for O(2) and CO(2) levels, pH, filtration time, total volatile basic nitrogen (TVB-N), aerobic mesophilic heterotrophic bacteria (AMHB), and aerobic psychrotrophic heterotrophic bacteria (APHB) over 20 days at 2 °C. All MAP systems had a decrease of O(2) and an increase of CO(2) levels during storage period (p < 0.05). Overall, the MAP systems were similarly able to decrease the pH and retard the increase of TVB-N and filtration time over the storage period (p > 0.05). Moreover, the MAP systems increased the lag phase and/or the generation time of both AMHB and APHB, extending the shelf life by 3 (90O(2):10CO(2)), 4 (70O(2):30CO(2) and 100O(2)), and 5 days (80O(2):20CO(2), 60O(2):40CO(2), 50O(2):50CO(2,) and VP). All MAP systems were equally effective in retarding physicochemical degradation; however, 80O(2):20CO(2), 60O(2):40CO(2), 50O(2):50CO(2,) and VP were the most effective in impairing bacterial growth and extending the shelf life of ground beef stored under refrigeration.