Is gas enough to guarantee the shelf life of a package?
When a food product is packaged in a protective atmosphere, people tend to think that everything depends on the gas mixture injected into the packaging. The lower the oxygen level, the more protected the product will be. The greater the volume of nitrogen, the better the preservation.
Yet the reality is more complex.
In many cases, gas quality is only part of the equation. The tightness of the packaging also plays a decisive role in the actual shelf life of the product.
Why is a protective atmosphere not always enough?
The aim of a protective atmosphere is to slow down the phenomena responsible for the deterioration of the product.
In products rich in fat, such as potato chips for example, oxygen promotes the oxidation of oils, which can lead to a loss of flavor.
That is why manufacturers usually replace the air in the packaging with nitrogen.
But a question remains: What happens if this protective atmosphere gradually escapes from the packaging?
A micro-leak can allow outside air to enter while letting the protective gas out. Even if the gas mixture was perfectly compliant at the time of conditioning, its composition can change rapidly.
This situation can lead to two major consequences:
- Rancidity as mentioned earlier, with a loss of flavor caused by oxygen entering the packaging.
- The loss of crispiness with softening of the chips, caused by humidity. A leak also allows the water vapor present in the ambient air to gradually enter the packaging. The chips then absorb this moisture and lose their crispy texture.
In both cases, the success of packaging depends not only on the gas injected at the outset, but also on the ability of the packaging to maintain this protective environment throughout the product’s lifetime.
Why gas is not always the most effective lever
When a manufacturer seeks to improve the shelf life of a product, the reflex is often to act on the gas parameters:
- Reduce residual oxygen
- Increase the volume of nitrogen
- Modify the gas mixture
However, improving watertightness can sometimes produce a more significant effect.
A very small leak can have a major impact on the rate of renewal of the atmosphere present in the packaging.
The more airtight the packaging, the longer it retains the protective conditions initially intended.
A concrete example: the case of chips
A chip manufacturer generally packages its products under nitrogen to limit the oxidation of fat and preserve crispness.
In this case, the manufacturer often seeks to improve shelf life by increasing the volume of nitrogen or reducing the amount of residual oxygen.
However, the sealing of the packaging can have an equally important impact on product preservation.
A micro-perforation caused by the friction of a chip on the film or by the presence of debris in a weld can considerably accelerate the renewal of the internal atmosphere.
In some cases, improving the hermeticity of the packaging may have a greater effect on preservation than increasing the volume of nitrogen injected.
👉 See the full replay of the Elo Quality webinar: “Your packaging with or without bubbles?”
Conclusion
Protective atmosphere plays an essential role in the shelf life of food. But its effectiveness depends on its ability to remain stable throughout the life of the product.
At Anéolia, gas control and sealing solutions allow us to simultaneously assess the quality of the protective atmosphere and the packaging’s ability to preserve it over time. This approach helps manufacturers better understand the factors that influence shelf life and make decisions based on measurable data.