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Measures freshness in three seconds

NORWAY - Do you wonder whether the fish you buy is fresh? Technology developed at Fiskeriforskning can make it possible to measure freshness in just three seconds.

The fish you buy in the shops isn't always as fresh as it should be. But it can be difficult to ascertain when the fish actually starts going bad. Fresh fish is a complicated theme indeed.

Today's methods of measuring freshness aren't good enough because they only measure one indicator of whether the fish is fresh, such as texture, smell or colour.

Therefore, scientists at Fiskeriforskning have in recent years developed new technology - and a finished prototype - for a measuring device that can tell how fresh the fish is in just three seconds.

Fast and reasonably priced

Not only is the new method considerably faster - to put it mildly - than traditional analyses, which can take anywhere from a few hours to several days, the new device is also inexpensive to make and is sized so that it can be used in the seafood shops.

"The actual device is only 25 cm long, and can be manufactured for a fraction of the costs of the larger analyser", says Senior Scientist Heidi Nilsen.

"In addition, the method is reliable and, in a few seconds, gives an answer about how long the fish has been stored and whether it is fresh or not."

Measure with light

The scientists use light at different wavelengths - so-called VIS/NIR spectroscopy - to find out how fresh the fish is. The fish flesh will absorb light at different wavelengths according to how it is stored and how long it has been since it was caught.

The fillet is scanned by the instrument - and one has a reliable answer in a few seconds. The consumers can thus be assured that they are buying high-quality fish, and we can avoid scandalous publicity about old fish in the cold counters.

"These analyses can be used in seafood counters as well as in the industry, where they can be used on the production line to ensure that fresh raw materials are used and that high-quality products are delivered", says Senior Scientist Margrethe Esaiassen.

"We still have a way to go before the method is finely tuned. For example, we have to see whether we need to adjust it according to how the properties of the fish flesh change during the year", concludes Esaiassen.

TheFishSite News Desk