Shelf-life extension and colour stabilisation of beef packaged in a low O(2) atmosphere containing CO: Loin steaks and ground meat.

A combination of low O(2), high CO(2) and very low CO was investigated for packaging fresh beef steaks and ground meat. The following atmospheres were used: 70% O(2) + 20% CO(2) + 10% N(2) (CMA); 70% O(2) + 20% CO(2) + 9% N(2) + 1% CO (HOCO) and 24% O(2) + 50% CO(2) + 25% N(2) + 1% CO (LOCO). Bacterial counts showed that LOCO atmosphere greatly reduced psychrotrophic population, so that log cfu cm(-2) was under 7.5 at 29 days of storage at 1 °C. All the objective measurements related to meat colour (a(∗), hue, Chroma and metmyoglobin concentration) revealed that the bright-red colour was more stable in both HOCO and LOCO atmospheres, reaching 29 days of storage without appreciable signs of oxidation. Sensory analysis confirmed these results.