We have developed a range of MAPAX® solutions to overcome the challenges facing meat (beef, pork and poultry) specialists.
Carbon dioxide (CO2) generally has a strong inhibiting effect on the growth of bacteria in meat and poultry. In the case of fresh meat, the aerobic genus Pseudomonas poses the greatest problem.
Discoloration caused by oxidation of the meat’s red pigment is a particular challenge. To retain its red color, fresh meat needs an atmosphere with high levels of oxygen (60 – 80%). This maintains high oxygen levels in the meat's myoglobin. Highly pigmented meats, such as beef, require higher oxygen concentrations than meats with low pigmentation levels, such as pork.
With the right MAPAX mixtures, at +3 oC the practical shelf life of consumer-packaged meats can be extended from 2–4 days to 5–8 days. By using master packs in distribution, high CO2 levels can lengthen shelf life even further.
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Protective atmospheres – MAP mixtures – meats
Product |
Red Meat |
Poultry |
MAPAX gas mixture |
20% CO2 and 80% N2 |
50-80% CO2 and 20-50% N2 |
Gas volume on weight basis |
100-200ml per 100g meat |
100-200ml per 100g meat |
Typical shelf life |
2-4 days in air 5-8 days with MAP |
7 days in air 16-21 days with MAP |
Typical material* |
OPET/PVdC/PE-PVC/PE |
OPET/PVdC/PE-PVC/PE |
Typical machine |
Deep-draw machine |
Deep-draw machine |
Storage temp. |
+1 oC to +3 oC |
+1 oC to +3 oC |
| *PVC is being replaced by APET or PS/EVOH PVdC is being replaced by WVOH or OPA |
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Poultry
Poultry is highly susceptible to bacterial spoilage, evaporation loss, off-odor, and discoloration and biochemical deterioration. Sterile poultry tissue quickly becomes contaminated during evisceration.
Gas-packed poultry has a practical shelf life of between 16 and 21 days. The head-space volume should be nearly as large as the product volume. Unlike red meats, the surface of poultry does not irreversibly discolor in the presence of oxygen.
Spoilage of raw poultry is mainly caused by microbial growth, fuelled by the pseudomonas and achromobacter genera in particular. A modified atmosphere containing CO2 effectively inhibits the aerobic bacteria. Levels of CO2 in excess of 20% are required to significantly extend the shelf life of poultry.
When packaging raw poultry, problems associated with collapsed packaging and excessive dripping can be avoided by increasing the gas/product ratio if higher levels of CO2 are used. Where package collapse is not an issue (e.g. bulk or master bags), 100% CO2 is recommended. In both retail and bulk modified atmosphere packs, nitrogen is used as an inert filler gas.
