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The results of the research, compiled by packaging firm Sealed Air Cryovac, were revealed by Cryovac Food Solution's European retail director Christophe Gottar at a recent seafood conference organised by the company.

The research looked at fresh and frozen fish in 112 stores across Europe and found that fish made up an average of 0.99% of retail offerings in supermarkets. However, this figure rose to 1.56% in the UK. And while the European average for fish availability was 40.5% for frozen and 59.5% fresh, the UK had homed in on consumer demand for convenience and made over 70% of fish available as fresh.

Nevertheless, the UK still has plenty of room improvement. "At the moment there are plenty of two portion packs in the UK," said Gottar. He added: "The UK could further segment its offer by looking at consumer income, size of household and age. Fish stock keeping units could be increased, with more single and family portion packs."

There were also opportunities for more convenience products, he claimed. "The UK is perhaps not playing enough with the concept of cooking in pack." Products such as Cryovac's Darfresh vacuum skin packaging technology would enable consumers to steam cook fish effectively in the microwave without having to put it in a pan or the oven, he added.

But the format of packaging is not the only area where manufacturers could make changes for the better.

"We must not forget that there is a safety risk with fish," said Paul Dalgaard, senior scientist at DTU Aqua, the Danish National Institute of Aquatic Resources. Processors often do not monitor product temperatures for bacterial growth as well as they might, he claimed.

"We need to look at the growth of bacteria as this determines shelf-life; and we need to ask every time whether pathogenic microorganisms are at the same stage as spoilage microorganisms," he said.

"People who work with fish know this for constant temperatures, but what about dynamic scenarios?" he asked. "For example, if a fish spends three days at 0°C, three days at 2°C, 12 days at 8°C and two days at 3°C, then what shelf-life would it have? I think most people don't know the answer to this very simple question."

Dalgaard urged processors to get on top of the issue by downloading DTU Aqua's Seafood Spoilage and Safety Predictor, available from http://www.aqua.dtu.dk.

Superchilling to extend shelf-life

As well as looking at the safety of fish, the conference also examined how processing temperature could affect its shelf-life.

Morten Sivertsvik, research manager at the Norwegian Norconserv Seafood Processing research institute, claimed that 'superchilling' could work wonders for the shelf-life of fish. Superchilling involves lowering the temperature below 0°C to the point where the product starts to freeze (between approximately 0°C and -3°C).

During its first six days, a processed fish is in its prime quality phase, said Sivertsvik. Between seven and 10 days, it enters its second phase, in which the quality has deteriorated slightly, but there is no odour. Next, comes the third phase, where the product has some sour and lightly sweet odours, he added.

"MAP [modified atmosphere packaging] primarily extends shelf-life over the second and third phase - but superchilling could extend the first phase," said Sivertsvik. "By combining superchilling and MAP you can have virtually no bacteria growth at all over 24 days - the product will eventually go bad, but it will not spoil microbiologically."

Norconserv has already tried superchilling as a pre-treatment for salmon, with impressive results. "Within one hour of being out of the freezer, there'll be no [icy] crust and it will look chilled, but the temperature will be around -1.5°C instead of 5 or 6°C if it was just chilled normally," said Sivertsvik. "After six days, the temperature is still -1.5°C." Superchilling would also eliminate the need for ice, resulting in more product being transported per truckload, he added.

Seachill - a major fish packer for Tesco - is keen to investigate this technology. "What most people don't understand is that just chilling a fish doesn't slow down the bacterial growth because fish are used to the [cold temperature of the] sea," said Seachill's purchasing manager Diane Gibson. "We found the concept of superchilling very interesting."

Are we in for a superchilly summer? FM

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