Superchilling keeps fish fresh longer, claim scientists

By George Reynolds

- Last updated on GMT

Related tags Sintef Norway

Superchilling methods are being developed by Norwegian scientists
to extend the shelf life of fish and meat, while reducing storage
and transport costs.

Ways to store products are being sought that combine the extended shelf life of freezing, while retaining the fresh taste that chilling provides.

The conventional storage of fish requires crushed ice, which adds to the weight being transported.

Furthermore, melting ice can result in an increased risk of contamination spreading.

Scientists at the Foundation for Scientific and Industrial Research at the Norwegian Institute of Technology (Sintef) Energy Research claim that superchilling fish or meat between -1C to -3C (30F to 27F) helps the products stay fresher for longer.

Superchilling salmon fillets extended the freshness by up to five days, against conventional refrigeration, while up to 26 days were added to shelf life of pork chops, according to Sintef tests.

Anne Karin Torstveit Hemmingsen, Sintef's superchill researcher leader, said the technology is partly a matter of freezing, but the low ice content ensures the food stays tasting fresh.

"Superchilling also makes it less likely that the products will disintegrate during the production and packing processes," she stated.

If fish is slowly frozen, large ice crystals form, which damage muscle structure.

Fast and controlled superchilling just below freezingpoint will only freeze the loose bound water of fish, claims Sintef.

The amount of ice crystals that form will depend on the product type and conditions, but below a critical level.

Sintef scientists have tested cold air tunnels to superchill food.

Depending on the volume of products and other factors, food can be superchilled in minutes to hours.

Research is being conducted to find the optimum method of superchilling different products within different environments.

The first commercial Norwegian superchilling plant, by Nortura, is due to open soon, while scientists are developing cold tunnels for installation on fishing vessels.

This year, the use of brine as an ice substitute is being researched by the scientists.

They are testing whether superchilling using brine will form less ice crystals, providing another method for storing fish in particular.

Sintef claims an important discovery is that food stays fresher for longer if the post-superchilled temperature is kept constant, and therefore the ice structure remains unchanged for longer.

The research on chilling technology, which has been conducted over several years has been funded by Research Council of Norway and Norwegian industry.

Over the next five years Sintef, with other scientists and industry, will be running a NOK 30m (€3.7m) program to further research superchilling as part of a larger food processing project.

The project aims to open more export markets for Norwegian food.

Many of Norway's European markets are distant and require long transport times.

Reducing the weight and cost of ice, as well as allowing more fish to be transported will make exports more competitive against those sourced closer to the market.

The final goal of the project is to develop knowledge and expertise to double the shelf life of fresh food using current cold chain methods, Sintef said.

Sintef is an independent research organisation that supports the development of about 2000 Norwegian and overseas companies.

It main operations are in Norway, with further offices across Europe and the US.

Related product

Related suppliers

Follow us


View more