Fishing industry's reliance on ice called into question –

Fishing industry’s reliance on ice called into question Published:  07 February, 2013

A RESEARCH project in Norway has called in to question the fish industry’s reliance on ice and insulated boxes to keep its products fresh, claiming this practice is costly and “prevents innovation in the sector” while an alternative could be provided by “super chilling”.

According to the Nofima study, in 2010 Norway exported 922,000 tons of salmon, the vast majority of which was packed fresh in polystyrene fish boxes with 5–6 kg of ice for every 22 kg of fish. This is equivalent to 7500 articulated lorries full of ice.

It generally takes 24 hours to chill the fish using ice 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.

However, 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. The best method is to store the cold in the fish by reducing the temperature down to the equalisation temperature of the fish, typically -1 to -2°C. This method is called super chilling or deep chilling. 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 (0 to +2°C).

There are many solutions for super chilling fish, including the use of air or cryogenic mediums, contact and air blast freezers, super-chilled brine and dry ice. The most rapid we have tried is air impingement, in which a processing time of up to a minute provides good results and an equalisation temperature in salmon of around -1°C after 45–60 minutes. This, combined with a simpler distribution packaging, eg corrugated fibreboard (which costs half the price of traditional fish boxes and which may be used when meltwater 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 utilisation – and, as an added bonus, a more environmentally-friendly solution.