If fruit and vegetables are packed in air, they are exposed to atmospheric conditions which can lead to undesirable changes to the product. The main influences here are oxidation by atmospheric oxygen as well as microbial infestation by bacteria and mould. These unwanted influences can be suppressed or reduced by packing under a modified atmosphere (MAP: Modified Atmosphere Packaging). Furthermore, the natural respiration rate of the product is supported by the choice of suitable gas mixture and packaging materials.
When packaging under a modified atmosphere a variety of gases are used, for example carbon dioxide (CO2), Argon (Ar), nitrogen (N2) or oxygen (O2) as well as mixtures of several of these. In addition to displacing the ambient atmosphere, protective gases can reduce the oxidative changes to foodstuffs or microbial activity. By packaging under a protective gas atmosphere, the shelf life of food can be extended by up to three times the normal value.
A modified atmosphere offers the following advantages:
- Extended shelf-life
- Longer preservation of sensory properties such as appearance or taste
- Reduction in microbiological activity in product