Reports

Seasonal variations in quality and processing properties of whiting (Merlangius merlangus) by season

Published:

30/10/2011

Authors:

Ásbjörn Jónsson

Supported by:

Fisheries Project Fund

Seasonal variations in quality and processing properties of whiting (Merlangius merlangus) by season

The aim of the project was to build up a specific knowledge base for cod (Merlangius merlangus) and obtain information on the variability of its quality and processing properties (chemical and physical properties) according to the season. For comparison, information on haddock was used. The results showed that fillet utilization (processing utilization) was related to carcass production, as there was a positive correlation between fillet utilization and body mass index, which was noticeably highest in March. At the same time, there was less release in the fish compared to other seasons. The results of the project seem to indicate that it is not appropriate to fish for halibut around the spawning season, or in the middle of summer, in terms of processing, physical and other quality characteristics.

The aim of the project was to study seasonal variation in quality and processing properties of whiting (Merlangius merlangus). Haddock was used as a reference group. The results showed positive correlation between fillet yield and condition factor, with highest value in March. At the same time gaping was minor. The results indicated that during spawning time it is not suitable to catch whiting with regards to processing‐ and quality properties.

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Reports

Catfish. Catch, markets, utilization and chemical content / Atlantic wolffish. Icelandic catch volumes, markets, yield and chemical content

Published:

01/01/2010

Authors:

Kristín Anna Þórarinsdóttir

Catfish. Catch, markets, utilization and chemical content / Atlantic wolffish. Icelandic catch volumes, markets, yield and chemical content

The report is a brief overview of the state of the knowledge available today on the catch volume, life pattern, utilization and chemical content of catfish caught in Iceland. The Marine Research Institute has been working on research into the distribution and life pattern of catfish in the sea around Iceland. Statistics Iceland's statistics show developments in, among other things, fishing and the disposal of catfish catches. Knowledge of the variability in the processing properties and chemical content of the fish is limited and nothing was found about the stability of catfish products during storage. The research based on utilization and chemical content is based on older data from IFL (now Matís ohf) from around 1980. They show that, as with other species, the condition of the fish is highly dependent on the time of spawning and the time of year. What makes catfish different from more common species such as cod is that it loses teeth during spawning and guards its eggs which inhibits food acquisition.

This report is a broad literature review about catch volumes, reproduction, yield and chemical content of Atlantic wolffish caught in Icelandic waters. The Icelandic Marine Institute has investigated the distribution, growth, maturity and fecundity of the fish and the Icelandic Statistics collects and produces statistics on fish catch, manufactured products and exports. Information about the variability in yield and chemical content of wolffish are limited and knowledge about the stability and degradation process of wolffish products is limited.

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Reports

Comparison of properties of farmed cod and wild cod in loose freezing / Effects of freezing on muscle properties of wild and farmed cod fillets

Published:

01/12/2008

Authors:

Valur Norðri Gunnlaugsson, María Guðjónsdóttir, Guðrún Anna Finnbogadóttir, Kristján Jóakimsson, Sigurjón Arason

Supported by:

AVS R26-06 / AVS R&D Fund of Ministry of Fisheries in Iceland

Contact

Valur Norðri Gunnlaugsson

Research Group Leader

valur.n.gunnlaugsson@matis.is

Comparison of properties of farmed cod and wild cod in loose freezing / Effects of freezing on muscle properties of wild and farmed cod fillets

A comparison was made of the effects of freezing on different cod fillets. The raw material was farmed pre rigor cod and wild pre and post rigor cod. It was also investigated how fillets sprayed with brine came out of the freezer. The results showed that freezing did not in any way reduce the quality of these products. They performed well in quality assessment, emissions did not increase in samples and there was little or no change in the chemical content of these samples. The products all came out well from the freezing, whether it was farmed fish or wild fish and what treatment he received during the slaughter process.

The research was part of the project "Processing and quality control of farmed cod, more specifically a summary for work component 6.

In this project phase the aim was to look at effect of freezing on cod fillets from wild and farmed cod in different rigor stages. The goal was also to evaluate effects of brine injecting on the quality of the product after freezing and thawing. The results indicated that the freezing process did not affect the quality of those products. The quality assessment and chemical measurements did not indicate negative changes during freezing and thawing. All the samples got good results, both farmed and wild cod samples and the brine injection did not affect the quality of frozen products.

Report closed until December 2011 / Report closed until December 2011

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