Modified atmospheric packaging ensures higher quality of poultry

Poultry is an important protein source for millions of South African families, however it can potentially be host to a range of pathogens that cause severe food poisoning if it is not adequately stored and transported. As a result, the poultry and retail industries continue to place a greater emphasis on quality control throughout the entire supply chain.

One of the most effective ways to minimise the risk in the supply chain is to ensure that the cold chain is not broken. This will ensure that the product reaches the retailer in good quality, however shelf life remains an issue as the fresh product will start showing discolouration after a few days.

This challenge, which places the retailer at tremendous risk, can be overcome using modified atmospheric packaging (MAP) gases. Afrox manager for Special Products and chemicals, Marietha Strydom points out that the component gases in MAP are carbon dioxide, nitrogen and oxygen, which contribute different preservation benefits. “These are all present in the air that we breathe and are 100 percent natural.”

According to Strydom, the success of FoodFresh MAP lies in using the correct combination of these gases to inhibit deterioration of each specific type of food by using knowledge of the mechanism of deterioration. “Carbon dioxide is bacteriostatic and fungistatic, which means that it retards the growth of mould and aerobic bacteria, while nitrogen is used to displace oxygen where aerobic mechanisms dominate. It is also used as an inert filler gas to prevent pack collapse,” she says.

Strydom indicates that the spoilage of chilled poultry stored aerobically is largely due to growth of pseudomonas, especially Pseudomonas fluorescence, P. Putida and P. fragi. “When these organisms reach populations of 100 million per square centimetre, an ‘off-odour’ can be detected by smell.”

In a study, portions of fresh chicken under an atmosphere of 25 percent carbon dioxide balanced nitrogen lasted for ten days at 1oC to 2oC in trays with non-permeable film,without developing off-odours. At 3.3 oC, it was discovered that growth of Clostridium botulinum is possible in a MAP atmosphere. This toxin can cause severe flaccid paralytic disease in humans and is the most potent toxin known to humankind, natural or synthetic, with a lethal dose of less than 1 micro gram in humans. It is, therefore, essential for the product to be constantly maintained at 1 oC to 2 oC.

The studies revealed that higher carbon dioxideconcentration provides greater protection, although the tray packaging deforms, as the carbon dioxide reacts with moisture and forms a vacuum in the tray. Strydom adds: “Pure carbon dioxide is the answer for shipping bulk par-cooked chicken where a central kitchen distributes to stores, where the final cooking steps will be done.”

As consumers continue to become more health conscious and mindful of wastage, Strydom believes that the demand for FoodFresh will continue to increase steadily into the foreseeable future. The general trend is that people prefer fresh food as opposed to the frozen alternative. As the demand for, and production of food increases, so too will Afrox’s tried-and-trusted FoodFresh MAP gases.