MAP or Modified Atmosphere Packaging is a process that the food industry relies on to keep packaged goods fresh. It replaces the ambient air in packaging with a mix largely consisting of nitrogen. Why? The reason is simple and involves the makeup of the air that surrounds us.

It mainly consists of nitrogen (78%) and oxygen (21%). That’s a perfect mix for breathing but not ideal for keeping food from spoiling. To understand why, we have to first look at some of the properties of these two essential gases.

Oxygen is a highly reactive gas. As the name indicates, that means it reacts with other molecules and forms new chemical connections. While this is great for some chemical processes, such as starting fires, it isn’t good for food. Here, oxidization can cause great damage and spur the growth of microorganisms.

Nitrogen, on the other hand, is an inert gas. This means it prevents chemical reactions from taking place because it reacts poorly with other molecules. So, while oxygen is required for fire, nitrogen puts it out. For the same reason, oxygen helps spoil food and nitrogen helps preserve it.

It mainly consists of nitrogen (78%) and oxygen (21%). That’s a perfect mix for breathing but not ideal for keeping food from spoiling. To understand why, we have to first look at some of the properties of these two essential gases.

Oxygen is a highly reactive gas. As the name indicates, that means it reacts with other molecules and forms new chemical connections. While this is great for some chemical processes, such as starting fires, it isn’t good for food. Here, oxidization can cause great damage and spur the growth of microorganisms.

Nitrogen, on the other hand, is an inert gas. This means it prevents chemical reactions from taking place because it reacts poorly with other molecules. So, while oxygen is required for fire, nitrogen puts it out. For the same reason, oxygen helps spoil food and nitrogen helps preserve it.

That leaves one question: How do you make sure your food doesn’t come into contact with oxygen? The answer is modified atmosphere packaging.

In this process, as soon as the food is placed in the container, the ambient air surrounding it is expelled. At the same time, it is replaced with a gas mix consisting largely of nitrogen. While other gases are used for purging the ambient air, such as carbon dioxide and argon, nitrogen is the gas of choice. That’s because it isn't just inert but also odorless and colorless. This is crucial because any gas used for MAP comes into contact with food and has to be safe.

And that might be the greatest benefit of nitrogen. With a generator on site, you can produce an abundance of food-grade nitrogen. This ensures that you always have a supply for your food packaging needs. That nitrogen can also be used for inerting, pressurizing, purging, blanketing and sparging – all processes required to keep food fresh. 

The last “ingredient” in this recipe for food-grade nitrogen is quality compressed air. Because the nitrogen you generate is only as good as the air you use to produce it. That not just requires a compressor but also the right air treatment equipment like dryers and filters.

You want to make sure that you can eliminate any of the contaminants that spoil the food. These include moisture, oil residue and small particles.