Elísa Viðarsdóttir will give an open lecture at Matís, Vínlandsleið 12, room 312 on Tuesday 10 April at 15.45. Her project is called:
The golden head. Physical and chemical properties of cod heads. „The Golden head. Effect of size and season of catch on physicochemical properties of cod heads„.
Elísa's supervisors are Sigurjón Arason and Magnea Guðrún Karlsdóttir from Matís and María Guðjónsdóttir from the University of Iceland.
Catches of cod are in significant quantities and began early in Iceland, and cod has been one of the most important fish species in Iceland. The utilization of cod is good compared to many other species. The utilization of heads, especially for trawlers, has not been good enough, however, because the majority of freezer trawlers have not been able to bring their heads ashore due to lack of space and lack of equipment.
The aim of the project was primarily to promote further development and utilization of valuable products made from cod heads (Gadus morhua) to meet requests for new products in response to the volatile market for dried cod heads. The first step towards further development and value creation was to create an important knowledge database on the chemical and physical properties of different parts of the head, ie. cheeks, gills, eyes, brain and gels. When creating the database, it was necessary to take into account factors such as the biological variability of the fish, the time of year of fishing and the size of the fish. Once these factors have been carefully mapped, the path to further product development and value creation will become more purposeful.
Samples were taken in May and November 2017. Cats' eyes, brains, cheeks, gels and gills were examined separately with respect to fish size and season of fishing. The results of the measurements showed, for example, that the fat content in the brain was considerably higher than the fat content in the other four parts that were measured. The highest fat content was found in 6-7 kg of fish caught in November and its fat content was about 5%, but the fat content in the other parts (eyes, gills, cheeks and gels) was in the range of 0.2-0.9%. The results of this study showed that water always goes hand in hand with protein and fat in different parts of the head. When the water content was high, the fat and protein content were low. The ash content of the gills was higher than in all the other parts, probably due to the fact that the gills have a different composition than the other parts. The omega-6 / omega-3 ratio was high in all the components measured but in varying amounts. This high percentage is considered good for human health and therefore one more reason to work these parts out of the head separately.
Based on the results obtained from the chemical analysis of different parts of the head, there is every reason to work on these parts separately to increase the value of the head.