The method requires detailed knowledge about the properties of the cod fillet, because the CO 2 emitter has to be adapted to the product to ensure optimal shelf life. Photo: Jon-Are Berg-Jacobsen/Nofima

Project Year 2016

Cod lasts longer with CO2

 Food safety and quality  

An ingenious little pad that gently emits CO2, can extend the shelf life of a package of fresh cod by up to four days.

“This could play a huge role in reducing food waste,” says Nofima researcher Anlaug Ådland Hansen.

Nofima has developed this tiny, flat piece of revolutionary technology, known as a CO2 emitter, with funding from the Research Council of Norway and others.

CO2 emitter tailored to each raw product

Perishable food packets already contain a small pad under the food, which absorbs moisture. However, that is all it does.

By replacing the moisture-absorbing pad with a CO2 emitter, the shelf life of the product is also extended. When the emitter comes into contact with moisture from the food, it emits CO2, which inhibits bacterial growth, thereby extending the expiration date.

However, it is not quite as simple as it sounds: the CO2 emitter has to be precisely adapted to the individual product and its moisture content and weight. In addition, hygienic handling before the product is packaged is essential.

Tests Nofima has conducted show that the shelf life of vacuum-packed cod fillet can be seven days. Inclusion of a CO2 emitter increases the shelf life of vacuum-packed cod by two days, i.e. to nine days.

This is the first time a CO2 emitter has been tested in vacuum packs of cod.

Extended shelf life

Normal shelf life for the same cod fillet in packaging with a modified atmosphere (MAP) is up to nine days. If a CO2 emitter is included in MAP packs of cod, shelf life increases by up to four days, i.e. a total of 13 days.

The CO2 emitter tests with cod were conducted at a temperature of 2°C.

“The CO2 emitter is based on fairly new technology that is already in use. Our tests show that the emitters can be used in a very wide number of applications,” says Anlaug Ådland Hansen, while nevertheless stressing that although CO2 emitters help extend shelf life, it is the initial level of bacteria in the fillet that ultimately determines how long it will maintain the required quality.

The Research Council of Norway

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