Lamb meat colour is minimally affected under reduced oxygen concentration in modified atmosphere packaging

Abstract

This study investigated how modified atmosphere packaging (MAP) with lower oxygen concentrations affects meat surface redness compared to standard 80% oxygen MAP for sheepmeat. Colour measuring instruments assessed redness (oxymyoglobin to metmyoglobin ratio and a*) in M. longissimus lumborum (loin) and M. semimembranosus (topside) from 50 Merino lambs. After 5 or 20 days of vacuum storage, meat samples were re-packaged into one of five MAP treatments (0, 20, 40, 60, or 80% oxygen), and colour was measured after 2, 6, or 10 days of retail display. Decreasing oxygen from 80% to 40% showed no negative impact on loin redness during retail display. Topside samples under 40% oxygen exhibited lower oxy/met values than 80% oxygen MAP at 2 and 6 days, with no difference after 10 days. This finding highlights the potential to reduce MAP oxygen content to 40% without compromising surface redness, potentially mitigating adverse effects on eating quality.