Inert gas for food packaging

It has been known for many years that altering the composition of the atmosphere surrounding a food can result in useful increases in shelf –life. Some gases, such as nitrogen and argon, are inert and therefore show no inherent antimicrobial activity.

In inert gas packaging the air inside the container is replaced by inert gas either through the compensated vacuum technique or by flushing the inside of the package with inert gas.

For example, the shelf life of roasted coffee could be improved by replacing the air inside the package with an inert gas such as N2 or Co2. Although the latter is not an ‘inert’ gas, it is naturally present in the product.

The procedure applied is based in the initial application of vacuum followed by its release with the desired gases. The pressure in the package is in equilibrium with the atmosphere at the moment of sealing. Just like in air packaging, to prevent internal pressure rising due to degassing, coffee must be either packed after degassing or the package fitted with a one-way valve.

Inert gases restrict the growth of aerobic organisms, like mounds, by reducing the amount of oxygen present. To be effective, at least 98% of the inert gas needs to be present in the headspace atmosphere, and this must be maintained during storage.

From a legal standpoint the gas added to the package is considered a processing aid rather than an additive, since it dissipates on opening.
Inert gas for food packaging