Let's look at the yellow from fishing in the stomach - a study of factors that affect the value of cod / Factors influencing the quality and value of the Icelandic cod; a value chain perspective




Helga Gunnlaugsdóttir, Jónas R. Viðarsson, Ásta M. Ásmundsdóttir, Cecilia Garate, Hrönn Jörundsdóttir, Ingibjörg G. Jónsdóttir, Sigurjón Arason, Vordís Baldursdóttir, Þorsteinn Sigurðsson, Sveinn Margeirsson

Supported by:

Increased value of seafood (AVS), HB ‐ Grandi, Guðmundur Runólfsson hf, Fiskistofa, Hafrannsóknastofnunin, Matís

Let's look at the yellow from fishing in the stomach - a study of factors that affect the value of cod / Factors influencing the quality and value of the Icelandic cod; a value chain perspective

The aim of this project was to gather more detailed information than has previously been done on the chemical composition, processing properties and value of cod in the value chain. The main results of the study are:

• There was not much difference in the carcass of cod by season, but the carcass coefficient was slightly higher in December than around the spawning season (February-May) when it was lowest. No association was found between fish body and liver fat content.

• There was a positive relationship between hepatic index and liver fat content (R2 = 0.55). However, the relationship was not linear, but the fat content increased rapidly at a low liver factor but less as the liver factor increased. Likewise, the fat content of the liver increased with length and age in both hens and females.

Liver fat content, fish weight or body mass index do not provide conclusive evidence of fillet utilization. Likewise, the water content and water resistance of the fillets had little or no effect on production efficiency or emissions.

• The summary result of the assessment of the effect of sex, sexual maturity and age on fillet utilization is that there is a difference in fillet utilization between individual fishing trips, this difference seems to be somewhat dependent on the maturity of the fish and is according to available data lowest at maturity stage 4 (ie fish in spawning or spawning). It should be noted, however, that there is a considerable imbalance in the database regarding the distribution of puberty in individual fishing trips and there are relatively few samples of fish from stages 3 and 4 compared to stages 1 and 2.

A comparison was made of the concentration of PCB7 in cod directly from the sea on the one hand and after processing, ie in frozen fillets, on the other. There was no significant difference in the concentration of PCB7 in whole fish and frozen cod fillets, so fish processing does not seem to affect the concentration of these substances in the fillets.

• There was no statistically significant relationship between iron concentration (Fe), selenium (Se), lead (Pb) or PCB7 and gender, age or puberty. There is a statistically significant relationship between the concentration of mercury in the flesh of cod (ie in fillets) and age, length and sexual maturity. Mercury is known to accumulate in the flesh of fish with age and the results of this study are consistent with and based on these results.

The aim of this project is to collect more detailed data about the factors influencing the quality and value of the Icelandic cod during processing, were the end product is frozen fillet. Data were collected from 2007 to 2008 on fillet yield, water content, water capacity, gaping, parasites as well as the chemical composition (nutrients & undesirable substances). These variables are important for the quality and profitability of the cod industry. Emphasis has been laid on connecting these variables to data about fishing ground, season of fishing, sex, sexual maturity in order to increase our understanding on how it is possible to maximize the value of the catch. In addition, the liver from each individual cod was collected and the fat and water content analyzed. The results from this study show that there is a nonlinear relationship (R2 = 0,55) between the liver condition index and the fat content of the liver.

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