Superchilled food

Tests have shown that superchilled salmon fillets stay fresh four or five days longer, while the shelf life of pork chops treated in this way is extended by as much as 26 days.

“The technology is partly a matter of freezing, but the content of ice is so low that the products taste just like fresh food” says Anne Karin Torstveit Hemmingsen, who leads SINTEF’s superchilling efforts.

The secret is to chill the meat of fish to a much lower temperature than the fridge temperature of about 4 degrees Celsius or so that has been usual until now. SINTEF has shown that the products kept best if they are stored at a temperature of between one and two degrees below zero.

“The process results in what is known as “shell freezing”. Superchilling also makes it less likely that the products will disintegrate during the production and packing processes”

Several years of research on chilling technology of this sort have resulted in serious financial support from the Research Council of Norway and Norwegian industry. Together with colleagues from other departments of SINTEF, NTNU, Matforsk and industry, the SINTEF Energy Research scientists will be running a NOK 30 million research project over the coming five years. Superchilling is one of five work-packages that make up the project entitled “Profitable food processing”.

Improved quality

The aim of the project is to make the Norwegian food-processing industry more competitive in the global market. A longer shelf-life will make it easier for the Norwegian fishing industry to export fresh fish, since it is a long way to European markets. Superchilling allows transport costs to be greatly reduced because ice is no longer needed in the fish boxes, which means that refrigerated trucks can carry more fish.

Nortura A/S (a merger of the Gilde and Prior food companies) will soon open its first superchilling plant, and the company has great expectations of the new technology. The final goal is a superchilled chain all the way to the chilled-foods counter, and even better product quality that will benefit consumers.