Only 15 per cent said they would buy fish that was more than four days old. Nofima then tested 300 fish clients in Hamar, Stavanger and Troms with samples of six pieces of cooked cod with different harvesting dates.
The majority thought that the fish up to 13 days after capture day tasted so good that they would have bought it. Even 15 days after the date of capture, 30 per cent of the customers said that they would have bought the fish.
"In Norway, it seems be a romantic notion of how fresh the fish we buy in the store is. In reality, we accept to eat fish that is "old" if you do not know how old it is," says Mr stli.
Old fish rarely hazardous
Only 15-20 per cent of customers feared that they could get sick from eating fish older than two weeks that had been frozen. Mr stli was slightly surprised by this attitude of consumers.
"There is obviously a myth that has survived," he said.
If you reheat cooked fish, there is little in it that might make you sick, according to a fish researcher.
"Yes, fish often starts to smell bad long before it actually goes bad, so it's pretty easy to judge for yourself whether you should eat it or not, regardless of what the date on the label says," he said.
"I would say that even a rotten fish can be eaten without the consumer getting sick, if the fish is heat treated," says Mr stli.
Elena, a fishmonger in Tromsdalen, can confirm that customers would prefer to have completely fresh fish.
"It's about what they are accustomed to, especially here in the north. Here, customers would rather have the fish straight from the boat," she said.
As fish is coming in fresh in the evening, several times a week, customers can be offered completely fresh fish.
But some types of fish is good to be a couple of days old, for flavour, she says.
Salmon fillets are among the items the fishmonger sells that have a fairly long shelf life, and they need not be completely fresh to be of high quality. But consumers often need convincing of this.
Pros and cons of labeling
Fish are marked with labels showing durability of the fish and the date they were caught. It is a statutory scheme, which gives consumers the ability to assess for themselves how long the fish can be kept for before consumption.
This order for such labeling was introduced a couple of years ago, and Nofima scientists feared beforehand that the industry would be affected, as many consumers associate freshness with fish that are only a few days old.
Nofima researchers did a study where they presented customers with raw fillets. The study showed decreased willingness to purchase fish which marked the date that it was caught.
"The average buyer accepts eleven days since capture, when the catch date is not specified, but this fell to seven days when they were given the date of capture," says Mr stli.
There were no significant differences in attitudes of customers from Hamar, Troms and Stavanger.
Better to use a use-by date?
It's an interesting question as to whether it would have been smarter to provide the expiry date on the package, instead of writing when the fish was caught.
"My personal opinion is that consumers are not able to make an objective assessment of fish quality."
There are also many factors that play into whether the fish is of high quality that the consumer does not take into account, such as, the time of year, fishing gear, storage temperature and handling.
"You must remember that there are those who buy fish from fishermen to ensure that catches are equipped with the correct date of catch."
"My occasional observations at seafood counters shows that the capture date is not often requested by consumers before buying."
"It is usually staff recommendations and policies that counts to consumers," says Mr stli.
Public perception means frozen fish is an understated alternative to fresh fish, especially for the modern consumer who only buys food a few times a week.
"Frozen fish has gotten an undeserved bad reputation in relation to fresh fish," says Mr stli.
A study of Norwegian cod showed that British consumers taste little difference between fresh and thawed fish, although they could tell whether the piece of fillet was fresh or thawed.
Consumers were more likely to buy frozen fish when the labeling stated "Frozen at sea."
"Frozen fish is like a second class stamp in Norway, but it can actually be better than fresh fish," says Mr stli.