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Using Alternatives To Metabisulphite To Treat Prawns

SCOTLAND, UK - A Scottish company that manufactures a sulphite free treatment solution for prawns is embarking upon a campaign to raise awareness amongst fishing skippers who are still using the traditional application of sodium metabisulphite of the potential health benefits for crew in using more modern and effective alternatives.

John Davis, the managing director of Xyrex, the manufacturer of the sulphite free Prawnfresh treatment, says he is heartened by the number of skippers and processors who are now moving away from sodium metabisulphite to more modern and effective alternatives. However, there are still a number of operators who continue to use metabisulphite, which is an area for concern, he says.

Prawn skippers and shellfish processors have long used sodium metabisulphite as a treatment to prevent blackspot in prawns, which is a natural process that discolours the shell after capture. Although blackspot is harmless, it does affect the appearance of the prawns, which in turn can make selling the prawns difficult and increases the reject rate.

After capture at sea, prawns are still commonly dipped in a sodium metabisulphite solution, masking the development of blackspot. However, sodium metabisulphite is corrosive and can cause serious and expensive damage to equipment on fishing vessels and processing factories. There is also well-documented evidence that it is hazardous to the health of crewmen and processing workers because the Sulphur Dioxide fumes released during treatment can harm operators' airways and lungs.

Mr Davis says: Research has shown that metabisulphite can cause asthma attacks and trigger allergic reactions in workers using the product. Fortunately, modern technology has allowed the creation of alternatives that are safe to use and also more effective in their treatment.

However, he welcomes the increasing numbers of skippers and seafood processors who are now beginning to switch to sulphite free alternatives, which are safe to use, provide a better quality product with longer shelf life, and do not cause corrosion to valuable equipment. More educated buyers are creating the demand for the use of safer alternatives, he says.

Peter Willox, skipper of the Scottish fishing vessel Bountiful BF79, found that as well as reducing repair and maintenance bills, there was a significant increase in the price of his prawns after using Prawnfresh.

Since using Prawnfresh our reject rate has gone down from 10 per cent to three per cent giving us a seven per cent increase in yield, he says. This equates to an increase in box price of approximately 3-4.

Graeme Sutherland, director of Scottish processor Whitelink Seafoods, said: We switched to Prawnfresh so as to ensure that our valued employees are able to work in a comfortable and safe environment, without encountering any breathing difficulties. We have also found that this alternative treatment gives a better result to the end product in terms of appearance and quality compared with sodium metabisulphite.

Donald Kristensen, managing director of seafood processor Royal Fish Denmark A/S, states: All our employees used to have general breathing problems including irritated eyes and nose. This is no longer an issue after changing to Prawnfresh.

The quality improvements are important too. He says: Tests have shown that prawns treated with Prawnfresh stays nicer in colour, texture and odour, longer than raw material treated with sodium metabisulphite. We also feel this alternative treatment is a healthier additive for the consumer.

the Fish Site Editor

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