The objective of this study was to investigate the effect of modified atmosphere packaging (MAP) with different oxygen concentrations on color changes of dark-cutting beef steaks from M. longissimus thoraces et lumborum. Four normal-pH (mean pH = 5.52) and four dark-cutting beef carcasses (mean pH = 6.36) were obtained from a commercial abattoir at 48 h post-mortem. The gas compositions in MAP were as follows: (i) 20% O₂/20% CO₂/60% N₂, (ii) 40% O₂/20% CO₂/40% N₂, (iii) 60% O₂/20% CO₂/20% N₂ and (iv) 80% O₂/20% CO₂. Steaks were stored in the dark at 2 °C for 14 days. Surface color of dark-cutting beef steaks was improved (P < .05) by 60%O₂-MAP and 80%O₂-MAP after 4 days storage, to a level similar to the initial normal-pH steaks. Steaks in 60%O₂-MAP and 80%O₂-MAP had lower metmyoglobin reducing activity and higher TBARS values (P < .05), but deeper oxygen penetration depth (P < .05) that may have masked discoloration resulting from metmyoglobin formation under the surface. While both 60%O₂-MAP and 80%O₂-MAP improved the appearance of dark-cutting beef, 60%O₂-MAP may be preferred owing to the lower level of lipid oxidation.

这项研究的目的是研究不同氧气浓度的气调包装（MAP）对长双歧杆菌（M. longissimus thoraces et lumborum）深色切牛排的颜色变化的影响。在死后48小时从商业屠宰场获得了四个正常pH（平均pH = 5.52）和四个切黑牛肉的屠体（平均pH = 6.36）。MAP中的气体成分如下：（i）20％O ₂ /20％CO ₂ /60％N ₂，（ii）40％O ₂ /20％CO ₂ /40％N ₂，（iii）60％ O ₂ /20％CO ₂ /20％N ₂和（iv）80％O ₂ /20％CO ₂。牛排在2°C的黑暗环境中存放14天。储存4天后，暗切牛排的表面颜色改善了（P  <.05）60％O ₂ -MAP和80％O ₂ -MAP，达到了与初始pH正常的水平相似的水平。在60％O ₂ -MAP和80％O ₂ -MAP中的牛排具有降低的肌红蛋白还原活性和更高的TBARS值（P  <.05），但是更深的氧气渗透深度（P  <.05）可能掩盖了由于肌红蛋白导致的变色在表面下形成。60％O ₂ -MAP和80％O ₂ -MAP均可改善深色切牛肉的外观，而60％O ₂由于较低的脂质氧化水平，-MAP可能是优选的。