Don't throw that away: How a few degrees might keep foods fresh

Scandinavian scientists say a new food-preservation method can keep organic foods fresh for up to 30 days. The discovery, called superchiling, has the potential to lower food waste in developed countries.

Thor Neilson/via SINTEF
A new method keeps salmon fresh for a whole month, without the use of chemicals, according to researchers in Norway.

Would you eat 30 day-old fish?

Researchers in Norway say you soon might, and it’s a matter of just changing the temperature.

Superchilling, as SINTEF labs calls it, is the process of cooling organic foodstuffs to just at the point where the food freezes, but not so cold that the food is frozen solid. The scientists first tried this delicate balance on salmon, and said in a statement: "At -2.5 (C) degrees below zero [27.5 degrees Fahrenheit], the fish is not completely frozen. It thus retains its quality of freshness, and will not be perceived or experienced as a thawed frozen foodstuff."

Fresh, not completely frozen, has implications for food storage, transport, and consumption across the globe.

As Discovery reported, every year, consumers in rich countries waste almost as much food (222 million tons) as the entire net food production of sub-Saharan Africa, according to the United Nations.

"The initiative is very positive," said project manager Michael Bantle in a statement. "We already know that superchilling is an efficient method, and if we can demonstrate that it can increase the shelf-life of organic produced foods as well as it does for conventional foodstuffs, we believe that there will be a market for superchilled products.”

The research team's emphasis on organic food, Bantle said, is due to the belief that the buyers of organic food are already more environmentally conscious, so those consumers may be more inclined to purchase a superchilled option.

Researchers at SINTEF have a few theories as to why their method has not already been put into practice.

The worldwide habit of throwing out food benefits food retailers, the report says, creates demand, and sales increase. Therefore grocers have no incentive to superchill products, even though the technology is already available.

“The supermarket chains ought to have invested more in cold-stores that are capable of keeping both fish and meat superchilled at quite stable temperatures,” said Bantle. “Unfortunately, this is not being done today because these chains prioritise the simplest and cheapest solutions.”

The EU's regulations currently classify superchilled food as frozen rather than fresh, even though it is identical in quality to fresh food, the researchers say. Another reason is that transporting food is cheap, which means producers are willing to pay to freight large quantities of the ice that gets packed with shipments.

SINTEF said in a statement that fresh salmon is transported in boxes that contain about 30 percent ice. This ice could be eliminated by superchilling the salmon because in this state the ice is inside the fish itself. Eliminating ice reduces weight, which brings down the amount of fuel needed. This in turn lowers CO2 emissions.

One challenge the researchers are already anticipating is exactly how to put a sell-by date on superchilled food. They are not yet sure when, exactly, the food will spoil.

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