Modified Atmosphere Packaging (MAP)

Modified Atmosphere Packaging (MAP)

Generally speaking, Modified Atmosphere Packaging (MAP) is the substitution of the atmospheric gas content inside a package by another gas mixture, O2 being usually removed to be replaced by nitrogen or carbon dioxide.

This is achieved by “flushing” another gas mixture into the package after the food has been placed inside, which results in the atmospheric gas content being replaced. The flexible packaging is then sealed hermetically.

The purpose of this operation is to extend the shelf life of the products, mostly perishable food, by reducing ongoing biological or physiological process.

A/ Advantages & disadvantages of MAP:

In addition to extending the shelf life, the other benefits are:

      1. Less or no preservatives.
      2. Waste reduction, because of longer product durability.
      3. Further world market penetration: new markets become attainable due to the extended shelf life.

However, the disadvantages would be:

      1. High investment & costs: MAP machines are an important investment, special gasses and special films usage resulting in high running costs.
      2. Process complexity: identification of the correct gas mix for your product and the adapted packaging material, proper injection of the gas recipe and capability to maintain the integrity of the gas recipe until the last day of the shelf life are an elaborate exercise. Adapted resources and an excellent Quality Control are necessary to ensure production reliability and consistency.

B/ MAP points of caution:

1. Gas mixture: the recipe is extremely variable, and depends on the compatibility of each product with O2 and CO2, together with its capability to maximize the extension of the product’s shelf life, as well as the effect it may have on changing the colour of the food. Meat, fish & seafood, dairy products, bread, fruits & vegetables, pasta, snacks, nuts and coffee can be packed with MAP.

Picked strawberries to be packed under MAP.

Even within the same sort of food, like fruits, for example, the maximum CO2 tolerated can vary from 2% to 15%, depending on the kind of fruit packed. It is the responsibility of the Food Manufacturer to ensure that the correct mix of gases is selected, and that it will remain undisturbed until the last day of the shelf life.

2. Selection of adapted packaging materials: The appropriate selection of the film adapted to the application is critical. MAP plastic films can be either laminated or coextruded. For coffee application, for example, high-barrier foil-based laminate, made out of multiple layers, are perfectly suitable to prevent oxygen, moisture, light, and extreme temperatures to enter the packaging after it has been sealed hermetically. For fruits however, you have to select a “breathable” film that allows some permeability, to achieve “Equilibrium Modified Atmosphere Packaging” (EMAP). The “breathable film” is required because the fruits will continue to consume O2 and produce CO2 and some water vapor after having been packed, so the film will allow their transfer both ways via permeation control, and therefore maintain the integrity of the original gas mix.

3. Preventing leaks: leaks are the enemy number one of MAP packaged foods. During transportation to their retail destination, packaged food can be subject to a certain number of stresses: pressure differences, package compression, extreme temperatures leading to the escape of the gas recipe from the packaging, and its subsequent undesirable replacement by atmospheric gases like O2. This may have consequences before the end of the shelf life of the product, like loss of taste, sogginess, mouldy appearance, change of colour, and in the worst-case scenario, food may become unsafe to consume.

C/ What can the Astaara products do for you?

All the benefits of the MAP are lost if the package leaks excessively. It is therefore absolutely necessary to ensure that the sealing has been correctly achieved to retain the gas recipe inside the packaging. However, “zero leak” does not exist. What needs to be determined is the maximum permissible leak value for your product, to ensure that it remains consumable and it retains his important characteristics like taste, crispiness and colour to maximize Customer experience, all this throughout the duration of the shelf life.

With the GammaLab, you can establish a relation between the size of the leak and the change of the O2 content of your gas recipe in your packaging over a period of time. You can then determine your Critical Limit, and make sure that your products are within the acceptable range & that they will be correctly preserved until the last day of their shelf life.

With the GammaPro, the O2 concentration inside the packaging of the products can be automatically measured without any human intervention, in order to compare it with the O2 concentration that the machine is delivering. Monitoring and reporting of this value is particularly useful when production is switched during nightshift to another product with a different gas recipe for example, which allows inspection to take place the next day by the Supervisor that the gas modification was correctly executed.

Perform automatically a leak test just after, and check that the result is within expected range as per your HACCP Plan.

D/ ISO 22000 & HACCP: a Qualified Internal Auditor is ready to help you:

If you are part of the Food Safety Policy Team or a Food Safety Team Leader, a Qualified Internal Auditor (ISO 22000 & HACCP) in our Astaara Team is ready to assist you. We can contribute to analyze your current packaging process, and help you with the evaluation of the current situation and the best solution for your Business.

We are here to help, so please do contact us.