From the Toronto Star, Sunday, June 17, 2001 Peat moss said to keep fish fresh for weeks Norwegian research suggests trawlers could save millions BY NICOLA JONES SPECIAL TO THE STAR NEW YORK Fishing boats should be packed with peat moss instead of expensive freezers, Norwegian scientist says. Peat can keep fish fresh for weeks and would make shipping to distant ports dirt cheap, their research shows. "If my dream comes true, we might save the Norwegian economy billions of kroner every year," says Terence Painter of the Norwegian University of Science and Technology in Trondheim. Sphagnum moss, which over hundreds of years compacts down to form peat bogs is an incredibly effective natural preservative. A fully clothed 2,000-year-old body, 6,000-year-old crumbs of uneaten bread and 1,800-year-old kegs of butter all have been recovered in good condition from such bogs. At first, researchers thought the lack of oxygen, low temperatures and acidic environment banish decomposing agents such as bacteria. Others later suggested that chemicals called tannins in the peat act as a preservative. But Painter has proposed that an unusual oxoploysaccharide - a sugar with reactive carbonyl groups attached - is responsible. He named the complex sugar "sphagnan". Painter and his collegues, Yngve Borsheim and Bjorn Christensen, set out to demonstrate the preservative ability of this sugar using strips of salmon skin and whole zebra fish. "There's a lot of peat here in Norway and very little of it is used. There's also a huge fishery, so we hoped we could connect the two," he says. The Norwegian government is sponsoring the study. The researchers encased the fish samples in beds of either untreated peat, sphagnum moss, a powdered white extract including all the polysaccarides in the moss, or wood cellulose as a control. The fish were periodically removed, rinsed with water, checked for colour changes and sniffed for signs of decay. After between nine and 28 days, the fish were removed to a bed of nutrients to see how long it would take before bacteria began to grow. Fish that had been stored in the peat or moss stayed fresh for about a month. And bacterial growth after removal was delayed by between seven and 12 days. "After two days of normal keeping, the smell of putrefaction is disgusting," Painter says. "After four weeks at room temperature in peat, it smells fresh. It's absolutely staggering." The reseacheres suspect that the carbonyl groups help preserve the fish by tanning the skin, making it unappealing to bacteria. "Exposure to wood smoke has exactly the same effect," Painter says. The same chemical process also gives bread crusts, soy sauce and black coffee their colour. Sphagnum moss that had been chemically reduced to remove the carbonyl group had no preservative effect. Painter thinks this proves that sphagnan sugar is the active ingredient. "I consider the case closed." He believes the peat could be used all over the world as a cheap preservative but adds that more testing is necessary - including taste tests. "I'm eager to sit down and eat a salmon preserved in peat." he says. "I would have eaten these fish, but they were quite small." NEW SCIENTIST