Effect of Raw lngredient Surface Area, Storage Time and Antioxidants on Color and Oxidative Stability of Ground Beef in 80% Oxygen Modified Atmosphere Packaging

Fresh beef packaged in high-oxygen modified atmosphere packaging (MAP) has longer red color stability than beef in oxygen-permeable polyvinyl chloride (PVC) film. However, fresh beef in high oxygen becomes rancid by 10 days storage at 2°C. Thus the objective of this study was to evaluate the effectiveness of various antioxidants (milk mineral, MM; sodium tripolyphosphate, STP; vitamin E, E) on color and thiobarbituric acid (TBA) values of ground chuck stored in 80% oxygen MAP for 14 days at 1° C. A preliminary experiment was also done to determine the effect of raw meat history (surface area during storage and storage temperature) on stability of ground beef in 80% oxygen MAP. For the preliminary experiment, select beef clods ( 48 hrs postmortem) were cut 11 into trim or coarsely ground and stored frozen or at 2°C in vacuum packaging (VP) for 30 days. Raw meat was then finely ground and wrapped in PVC film or in 80% oxygen. For experiment 2, fresh beef clods were coarsely ground and antioxidants (0.75 or 1.5% MM; 0.25 or 0.5% STP; 50 or J 00 ppm vitamin E) were added, followed by fine grounding and packaging in 80% oxygen MAP. Thiobarbituric acid assay was performed as a measure of rancidity. Hunter color L*, a*, b* values were measured on raw samples through the packaging film. Trim history greatly affected stability of beef in 80% oxygen MAP. VP refrigerated trim yielded ground beef with low oxidative and color stability compared to frozen trim. In comparison of antioxidants, 0.75% MM gave highest redness values (13-15) and lowest TBA values (\u3c 0.5) after storage of ground beef in 80% oxygen MAP for J 4 days. STP-treated beef also had low TBA values(\u3c 0.5) at 14 days storage but samples were less red (a* of J 0-J 2) than MM- treated samples. Samples with E were slightly better than controls, with redness values of 7.9 and J0.8, respectively. Thus, iron-chelating agents (MM and STP) were very effective for preventing rancidity and improving color stability in ground beef packaged in a high oxygen atmosphere