[ TECHNOLOGY ] Proper on-board handling of fish contributes significantly to higher quality and longer shelf life
Insulated containers with lids can make all the difference Fish from the Icelandic fishing industry has an enviable reputation for quality. Insulated containers have contributed to this in no small measure.
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nboard handling refers to the conditions that fish are subjected to after harvest and up to the point of landing, when the fish is transferred on shore, according to the FAO. Proper handling is critical to slowing the process of deterioration, prolonging the shelf life, and maintaining the quality of the product. Better handling increases thereby the value of the catch. At a webinar organised by Seafood Source, Björn Margeirsson Research Manager at Sæplast and Associate Professor at the University of Iceland spoke about ways in which on-board handling could be improved to maximise the value of the catch. As he pointed out, the quality of the fish when it leaves the sea is at its peak—from that point on the quality will only deteriorate. Therefore, the main aim of on-board handling and storage is to reduce this deterioration for as long and as effectively as possible. Chilling and the maintenance of good hygiene conditions are critical for quality and shelf life during fish handling.
Improvements have come about in a series of small steps Iceland has a well-deserved reputation for exporting high quality fish. This has come about through investments in research and in developing technology which has led to incremental improvements over a period of decades. Up 54
Improvements in on board handling including the use of insulated containers has contributed to the increase in value of fish from Iceland.
to around 1970, fish was stored in bulk on shelves in the hold. Thereafter, shallow plastic crates were brought into use. These were much better but there was a tendency to overload them with fish and ice resulting in high pressure on the crates at the bottom of the hold. Plastic crates were replaced by insulated plastic containers in the 80s and 90s. These were much better at maintaining the temperature, but initial generations of these insulated tubs were so big and deep (660 litres with a depth of 58-60 cm) that the fish at the bottom of the tub was subject to sub-optimal pressure from the layers above. From the mid-90s these tubs were replaced by shallower insulated containers that
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typically had a depth of 40-42 cm and a volume of 460 litres, resulting in a weight loss of around 1.5 compared to around 2 for the 660-L tubs during one-week storage. The 460-L containers have since become the most widely used containers for fish in the Icelandic fresh fish industry. The holds in modern vessels in Iceland house rows of neatly stacked containers of this type and are often equipped with automatic systems for moving them around.
Bleeding and chilling determine fillet quality On-board handling starts with the catch arriving on board followed by, in some instances, sorting by
size and species. Mixing red fish with cod or haddock, for example, may have an impact on the quality of the latter, so it is better to sort them. Bleeding is the next stage and it is important to remove the enzymes and iron present in the blood which can otherwise compromise quality and affect fillet appearance. This step together with chilling are the most important determinants of fillet quality, emphasised Mr Margeirsson. Bleeding carried out within 30 minutes of capture gives the best results in terms of fillet colour. After that, the longer the interval before being bled, the more discoloured the fillet. Bleeding is followed by gutting which removes microbes from the fish and thus also helps to preserve
