MAPAX for Meat

We have developed a range of MAPAX^® solutions targeted specifically at the challenges facing meat (beef, pork and poultry) specialists.

Generally speaking, carbon dioxide (CO₂) has a strong inhibiting effect on the growth of bacteria in meat and poultry. The aerobic genus Pseudomonas is the largest problem for fresh meat.

Discolouration caused by oxidation of the red pigment in meat is a particular challenge. In order to retain the red colour, the atmosphere for fresh meat should contain 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, the practical shelf life of consumer-packaged meats can be extended from 2-4 days to 5-8 days at +3.33^oC (37.99^oF). If master packs are used in distribution, high CO₂ levels can further increase shelf life.

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.	+1.66oC to +3.33oC	+1.66oC to +3.33oC
*PVC is being replaced by APET or PS/EVOH PVdC is being replaced by WVOH or OPA

Protective atmospheres - MAP mixtures - prepared meats

Product	Sausages	Sliced cooked meat products
MAPAX gas mixture	20% CO2 and 80% N2	20% CO2 and 80% N2
Gas volume on weight basis	50-100ml per 100g product	50-100ml per 100g product
Typical shelf life	2-4 days in air  4-5 weeks with MAP	2-4 days in air   4-5 weeks with MAP
Typical material*	OPET/PVdC/PE-PVC/PE PA/PE	OPET/PVdC/PE-PVC/PE
Typical machine	Deep-draw machine Horizontal flow-pack	Deep-draw machine
Storage temp.	+4.44oC to +7.22oC	+4.44oC to +7.22oC
*PVC is being replaced by APET or PS/EVOH PVdC is being replaced by WVOH or OPA

Poultry

Poultry is very susceptible to bacterial spoilage, evaporation loss, off-odour, discolouration and biochemical deterioration. Sterile poultry tissue quickly becomes contaminated during the evisceration process.

The practical shelf life of gas-packed poultry is somewhere between 16 and 21 days. The head space volume should be nearly as large as the product volume. In contrast to red meats, poultry does not undergo irreversible discoloration of the meat’s surface in the presence of oxygen.

The spoilage of raw poultry is mainly caused by microbial growth, fuelled by the Pseudomonas and Achromobacter genera in particular. These aerobic bacteria are effectively inhibited by modified atmospheres containing CO₂. Levels of CO₂ in excess of 20% are required to significantly extend the shelf life of poultry.

To avoid problems associated with collapsed packaging and excessive dripping with raw poultry, the gas/product ratio should be increased 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.