A new research project conducted by Nofima concluded that ice and insulated fish boxes “provide a false sense of security that prevents innovation in the sector.”
In 2010, Norway exported 922,000 metric tons (MT) of salmon, the vast majority of which is packed in fresh polystyrene fish boxes with 5 to 6 kilograms of ice per about 22 kilograms of fish — equivalent to 230 million liters of water.
The ice reduces the temperature in the fish to 0 °C and then maintains this temperature. It generally takes 24 hours to chill the fish and around one-third of the ice melts during this process. In an unbroken and good cooling chain, which one should be able to demand of transporters in 2013, there will be minimal melting of the remainder of the ice. In other words, the customer receives 3–4 kg of ice per box of fish, which indicates that the transport and distribution has been in accordance with the regulatory requirements.
Since the 1990s Nofima has been working on alternative methods for transportation of fish, in which ice is not used and the chilling and packaging of the fish has been studied.
According to Nofima, the best method is super chilling — storing the cold in the fish by reducing the temperature down to the equalization temperature of the fish, typically -1 to -2 °C. Super chilling is the easiest way of increasing the primary quality period of the fish and may be combined with packaging in a protected environment of carbon dioxide and nitrogen, during both distribution and in consumer packaging. This enables high quality to be maintained for several weeks in a cooling chain that is in accordance with the regulations.
There are many solution for super chilling fish, including the use of air or cryogenic mediums, contact and air blast freezers, super-chilled brine and dry ice, the study said.
“The most rapid we have tried is air impingement, in which a processing time of up to a minute provides good results and an equalization temperature in salmon of around -1 °C after 45 to 60 minutes.”
This combined with a simpler distribution packaging, for example, corrugated fibreboard (which costs half the price of traditional fish boxes and which may be used when melt water is no longer a problem), means that investing in super chilling technology can be worth its while within a short space of time.
This solution will result in reduced transport costs, more fish per box when ice is no longer there, more boxes per pallet and better pallet utilization — and, a more environmentally-friendly solution.
