LAUSR

This paper reports the impact of modified atmosphere gas compositions with different concentrations of CO2/O2/N2 on physicochemical traits of beef steaks from M. longissimus lumborum and M. gluteus medius. Samples were stored at +2°C for 12days. The gas compositions were as follows: (i) 50% O2/20% CO2/30% N2 (MAP1), (ii) 65% O2/20% CO2/15% N2 (MAP2) and (iii) 80% O2/20% CO2 (MAP3). Packaging atmosphere did not affect CIEL*a*b* colour coordinates, which were affected by storage time and by muscle type. Lipid oxidation in M. longissimus lumborum was affected by packaging treatment; however packaging treatment×storage time interaction affected lipid oxidation significantly. Results showed that reduction of oxygen from the commercially used 80% to 50% does not negatively impact colour properties and state of myoglobin, but significantly lowers oxidative deterioration of M. longissimus lumborum at the end of storage.