U.K. scientists hunt for pink salmon key

Press, 6 January 1987, Page 26

U.K. scientists hunt for pink salmon key

By SANDRA MALER of Reuters (through NZPA) London

British scientists are trying to find a natural way of keeping salmon pink, instead of having it land on the dining table an unappetising grey. The problem has arisen because salmon bred in fish farms are deprived of algae which make them pink in the ocean. Unless they are fed a dye called canthaxanthin, they come out a fishy-looking grey. With increasing consumer distaste for additives in food, six scientists have formed a biotechnology company called Cell Systems to devise a way of producing the natural pink pigment, astaxanthin. “Our concept is to grow the algae which secrete the pink mechanism in fermentation vessels to make them available in fish ponds,” company chairman Dr Brian Kirsop told Reuters.

He said the algae would be harvested, dried and sold for inclusion in fish foods.

Dr Kirsop, a. microbiologist, said he formed the company in February because he and his colleagues had been searching for a commercial application of their skills. Dr Kirsop said the company had not yet decided whether to grow the algae itself or sell the technology to others. Either way, the algae should be on the market within a year. Salmon food, which is produced by big chemical concerns like Unilever

and British Petroleum, mainly consists of ground up fish. Canthaxanthin comes in only at a 75 per million ratio but at a high price. Canthaxanthin was used in the United States in tanning pills to change human skin colour, but its use for this has been banned. It is produced by Hoffmann-La Roche, the Swiss pharmaceutical company, who have a monopoly on the dye for inclusion in salmon feed.

Several algae, such as haematococcus, contain the pink pigment in small quantities. The problem is how to develop a species which would produce large amounts economically.

Once developed, the algae would be fed with a mixture of glucose and vitamins and then grow and reproduce in a big tank.

Cell Systems reckons the market to supply food to fish farms is worth up to one billion sterling a year worldwide. Interest in natural ingredients for fish food would draw particularly keen interest from Norway, China and Japan, where a lot of fish are bred.

The advantage with farmed salmon is that it is available fresh all the year whereas wild salmon has to be frozen ,off season.

Salmon farming is expanding. In Scotland, 7000 tonnes of farmed salmon was produced last year, more than 10 times as much as five years ago, compared with 1000

tonnes of wild salmon. . Most farms breed the fish from eggs in hatcheries until they are about 3i/ 2 years old and big enough to be sold. Dr Kirsop said Cell Systems was also involved in trying to find a way to freeze fish eggs without killing them.

“There is a business already in freezing embryos in cattle worth 100 million sterling a year and there could be a business in fish if the technology was developed,” he said. Cell Systems won a government award in October to develop such a system. “It’s a technology that doesn’t yet exist. Nobody can freeze fish eggs. They die when you freeze them because they form ice crystals inside,” Dr Kirsop said.

The Smart Award, a new award given for research in biotechnology or laboratory instruments with commercial applications, will provide Cell Systems with just under £50,000, about 75 per cent

of the cost of developing the technology.

“Freezing eggs would allow fish stocks to be improved and to have stocks of fish eggs at all times of the year,” Dr Kirsop said. “It would open a new option to the industry.”

But he said that the project, particularly relevant now when scientists and conservationists are worried about the plunder of natural fish stocks, was a long-term one.