The project "Processing of longline vessels" has now been completed, which aimed to develop and design new technical solutions for the application and handling of fish after fishing on board longliners with the aim of maximizing raw material quality, increasing work efficiency and reducing the cost of the process.
We went on a voyage on board Stefni ÍS 28 to test the refrigerator and the bleeding vessels on board, which are built and manufactured by 3X Technology. The purpose of that trip was to find out which processing method yielded the best results in terms of the quality of the raw material. Different methods (different groups) were tested with bleeding, gutting and cooling of the raw material on board. To assess the quality, the color and release of the fillets were then assessed in the processing of Hraðfrystihús Gunnvarar in Ísafjörður.
The main results of this project indicated that by allowing the fish to bleed in the sea, with a lot of water exchange, after the fish has been gutted and before it goes into cooling, it gives a better color quality to the fillet. When the release of the fillets was examined in the sensory evaluation, there was not a sufficiently significant difference between the groups, ie no single processing method differed in quality in terms of release.
The graph below shows a plot of three temperature sensors for group no. 1. One sensor in each fish. The fish were then arranged in a 440L tank at the bottom of the train, one fish located at the bottom, one in the middle and one at the top. You can also see from the graph how fast the fish cools down to approx. -0.5 ° C in 25 minutes when using the sludge coolers. The fish is then placed in a train where the temperature remains well below zero degrees until processing takes place a few days later.
The partners of the project are Matís ohf, 3X Technology ehf, Vísir hf, Brim hf, Hraðfrystihúsið Gunnvör hf and Samherji hf. AVS Research Fund (www.avs.is) and the Technology Development Fund support this project.
A report was published on the project, but it is closed. A summary of the report can be found here.
For further information, please contact Róbert Hafsteinsson, robert.hafsteinsson@matis.is.