Will salmon quality be changed with freeze thawing?

The Fish Site
by The Fish Site
12 February 2007, at 12:00am

NORWAY - Will the positive quality characteristics of salmon immediately after slaughtering (pre-rigor), keep during freezing and subsequent thawing? This is what scientists at Fiskeriforskning now want to find out.

It is well documented from before that salmon fillet manufactured pre-rigor has a better quality than fish that is filleted post-rigor. This is true for both salmonids and whitefish (such as cod, saithe and haddock).

- However, we know little about what happens after a pre-rigor fillet has been frozen and thawed, and will therefore try to establish if and how the quality has changed, says Project Manager at Fiskeriforskning, Torbjørn Tobiassen.

- It will also be interesting to see if there is a difference in quality in pre-rigor frozen fillet after thawing and cold storage compared with post-rigor frozen fillet, says the scientist.

In the study, the scientists will examine two different freezing processes using salmon fillet - a traditional process with single freezing, and an American method (TruFresh). TruFresh is a relatively new technology that is used for freezing fillets and portion-sized pieces of salmon. The method involves dipping the fillet in a freezing brine where the fish is rapidly frozen at -40 degrees Celsius. This method is used by our partner in the project, Norlaks Produkter AS, amongst others.

The storage test is expected to be completed by the end of 2007.

TheFishSite News Desk