Freezing fish too soon after catch can damage its quality, new research from Nofima has found. Haddock frozen before rigor mortis set in developed a yellow colour after 20 weeks in storage. This risk could hit both consumer trust and industry profits.
Surprising findings
Researchers had expected to see issues mainly with drip loss – the liquid released after thawing. Instead, they discovered that fish frozen “pre-rigour” turned yellow, while those frozen later kept their standard colour. Cod also showed more liquid loss if frozen too early, and the effect lasted up to a year.
A financial risk
“Both liquid loss and discolouration are highly unfavourable,” said project leader Svein Kristian Stormo. “The challenge is that freezing fish as fresh as possible is usually seen as best. But in this case, it causes greater problems.”
The findings suggest that companies could face significant financial losses if they do not adjust their freezing practices.
Timing is key
The study shows there may be good reasons to wait until fish are past the first phase of rigor mortis before freezing. But waiting too long also brings other risks.
Researchers emphasise that more controlled trials are necessary to determine the optimal timing for both haddock and cod.