Modified atmosphere packaging for lamb meat: evaluation of gas composition in the extension of shelf life and consumer acceptance

Convenience foods like chilled meat usually have a short shelf life. Modified atmosphere packaging (MAP) can be used together with refrigeration to retard meat degradation. This work evaluated the effect of MAP on the preservation and consumers acceptance of lamb meat. Lamb loins Longissimus lumborum were packed in five conditions: 15% O-2 + 85% CO2 (O15), 30% O-2 + 70% CO2 (O30), 45% O-2 + 55% CO2 (O45), 60% O-2 + 40% CO2 (O60), and Vacuum (control). Physicochemical, sensory, and microbiological analyses were carried out along 21 days of refrigerated (1 +/- 1 A degrees C) storage. Treatments O30, O45 and vacuum presented the lowest oxidation values: 0.60, 0.61 and 0.30 Malonaldehyde Kg(-1) respectively. Treatment O45 showed the highest a* until the seventh day of storage (16.64). In the sensory preference ranking test, O30 and O45 received best scores in the first and second weeks of storage, respectively. Treatments O30 and O45 delivered products with lower microbial counts than the other ones. Considering a balance between consumer preference and microbiological results, we propose the use of 45% O-2 + 55% CO2 gas composition to extend the shelf life of lamb loin.