Reports

Overview of available methods for thawing seafood / Solutions available for thawing seafood

Published:

01/06/2017

Authors:

Sigurður Örn Ragnarsson, Jónas R. Viðarsson

Supported by:

The Norwegian Research Council (Project number 233709 / E50)

Overview of available methods for thawing seafood / Solutions available for thawing seafood

There is a constant demand for quality raw materials that can be used for producing seafood products for high paying markets in Europe and elsewhere in the world. Suppliers of demersal fish species in the North Atlantic are now meeting this demand by freezing the mainstay of their catches, in order to be able to have available supplies all year around. This is partly done because of seasonal fluctuations in catches, which are harmful from a marking point of view. The fact that all these raw materials are now frozen demands that methods used for freezing and thawing can guarantee that quality of the raw material is maintained. There are a number of methods available to thaw fish. The most common ones involve delivering heat to the product through the surface, as with conduction or convection. These methods include water and air-based systems. More novel methods are constantly on the rise, all with the aim of making the process of thawing quicker and capable of delivering better products to the consumer. These procedures are however, often costly and involve specialized workforce to control the process. All in all, it depends greatly on what kind of conditions a company is operating under regarding which thawing methods should be chosen. This report identifies the most common methods available and provides information on their main pros and cons.

There is a constant demand from fish processing plants around the world for good raw materials from the North Atlantic for the production of products for demanding markets. To meet this demand and in view of the large seasonal fluctuations in catches of certain fish species, companies have decided to freeze the raw material for later use. This requires good methods for freezing the raw material, but it is no less important that the thawing of the raw material is good. There are many methods for thawing fish and other seafood. It has been most common to use heat transfer through surfaces with heat transfer or thermal conductivity. These methods are mostly based on the use of water or air as a medium for thawing. Newer methods exist that try to make the process faster and thus deliver a better product to consumers. However, these methods are often costly and involve a great deal of staff specialization. After all, it matters what kind of business it is and how the companies' situation is at any given time when thawing methods and technical solutions are chosen. This report identifies all the major thawing methods and the technical solutions available on the market today, as well as outlining their main advantages and disadvantages.

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Reports

Nutrient value of seafood - Proximates, minerals, trace elements and fatty acids in products

Published:

01/10/2011

Authors:

Ólafur Reykdal, Hrönn Ólína Jörundsdóttir, Natasa Desnica, Svanhildur Hauksdóttir, Þuríður Ragnarsdóttir, Annabelle Vrac, Helga Gunnlaugsdóttir, Heiða Pálmadóttir

Supported by:

AVS Fisheries Research Fund

contact

Ólafur Reykdal

Project Manager

olafur.reykdal@matis.is

Nutrient value of seafood - Proximates, minerals, trace elements and fatty acids in products

Measurements were made of the main substances (protein, fat, ash and water), minerals (Na, K, P, Mg, Ca) and trace elements (Se, Fe, Cu, Zn, Hg) in the main types of marine products prepared on the market. These included fish fillets, roe, shrimp, lobster and various processed products. Measurements were made of fatty acids, iodine and three vitamins in selected samples. Several products were chemically analyzed both raw and cooked. The aim of the project was to remedy the lack of data on Icelandic seafood and make it accessible to consumers, producers and retailers of Icelandic seafood. The information is available in the Icelandic database on the chemical content of food on Matís' website. Selenium was generally high in the marine products studied (33-50 µg / 100g) and it is clear that marine products can play a key role in satisfying people's selenium needs. The fatty acid composition varied according to the types of seafood and there were special characteristics that can be used as indicators of the origin of the fat. The majority of polyunsaturated fatty acids in seafood were long-chain omega-3 fatty acids. The amount of minerals was very variable in seafood and there are changes in the concentration of these substances in processing and cooking. There was little loss of the trace elements selenium, iron, copper and zinc during cooking. Measurements were made on both selenium and mercury as selenium counteracts the toxicity of mercury and mercury is one of the undesirable substances in marine products. In all cases, mercury proved to be well below the maximum levels in the regulation. Roe and roe products had the special feature of containing very much selenium but also very little mercury.

Proximates (protein, fat, ash and water), minerals (Na, K, P, Mg, Ca) and trace elements (Se, Fe, Cu, Zn, Hg) were analyzed in the most important Icelandic seafoods ready to be sent to market. The samples were fish fillets, roe, shrimp, lobster, and several processed seafoods. Fatty acids, iodine, and three vitamins were analyzed in selected seafoods. A few seafoods were analyzed both raw and cooked. The aim of the study was to collect information on the nutrient composition of seafood products and make this information available to consumers, producers and seafood dealers. The information is available in the Icelandic Food Composition Database. Selenium levels were generally high in the seafoods studied (33‐50 µg / 100g) and seafoods can be an important source of selenium in the diet. Fatty acid composition was variable depending on species and certain characteristics can be used to indicate the fat source. Polyunsaturated fatty acids were mainly long chain omega ‐ 3 fatty acids. The concentration of minerals was variable, depending on processing and cooking. Small losses were found for selenium, iron, copper and zinc during boiling. Both selenium and mercury were analyzed since selenium protects against mercury toxicity and data are needed for mercury. Mercury in all samples was below the maximum limit set by regulation. Roe and lumpsucker products had the special status of high selenium levels and very low mercury levels.

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Reports

Bacterial diversity in the processing environment of fish products

Published:

01/03/2010

Authors:

Eyjólfur Reynisson, Sveinn Haukur Magnússon, Árni Rafn Rúnarsson, Viggó Þór Marteinsson

Supported by:

Tækniþróunarsjóður, AVS

contact

Viggó Marteinsson

Group Leader

viggo.th.marteinsson@matis.is

Bacterial diversity in the processing environment of fish products

The report seeks to address the diversity and species composition of micro-organisms in fish processing environments. The research work began with the installation and development of methods for scanning microbial composition using molecular biological methods, and then at a later stage, work began on examining selected environments from the fishing industry. Two fish processing plants were visited, each twice where an evaluation was made of the processing and approx. 20 samples taken in each trip. A diverse community of bacteria was found, where known harmful bacteria were usually in a high proportion along with various other species. Microbial counts showed high levels of bacteria on the surface of production lines during processing with few bacterial groups in excess but also numerous other species in smaller quantities. The main groups of bacteria found belong to Photobacterium phosphoreum, which was in the highest proportion overall throughout the study, along with Flavobacterium, Psychrobacter, Chryseobacter, Acinetobacter and Pseudoalteromonas. All of these species are known fish bacteria that live in the redness and intestines of live fish. This is the first known project where molecular biological methods are used to scan the bacterial ecosystem of fish processing plants. A knowledge base has therefore been laid here for bacterial ecosystems in different conditions in fish processing, which will be used permanently in research and development of improved processing processes and storage methods for fish.

In this report we seek answers on diversity and species composition of bacteria in fish processing environment. The study initiated method development to screen microbial systems using molecular methods followed by analysis of samples from 2 fish processing plants. This research shows the presence of a diverse microbial community in fish processing environment where known spoilage microorganisms are typically in high relative numbers along with various other bacterial species. Total viable counts showed the presence of bacteria in high numbers on processing surfaces during fish processing where few species typically dominated the community. Photobacterium phosphoreum was the most apparent species followed by genera such as Flavobacterium, Psychrobacter, Chryseobacter, Acinetobacter and Pseudoalteromonas. All these species are known fish associated bacteria that live on the skin and in the digestive tract of a living animal. To our knowledge, this is the first study where molecular methods are used to screen microbial communities in fish processing plants. This research has therefore contributed a database on bacterial diversity in fish processing plants that will be used in the future to improve processing and storage methods in the fish industry.

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Reports

Proposals for the establishment of retail fish markets in Iceland / Public fish markets in Iceland - propositions

Published:

01/10/2009

Authors:

Þóra Valsdóttir, Brynhildur Pálsdóttir, Theresa Himmer

Supported by:

AVS Fisheries Research Fund

contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Proposals for the establishment of retail fish markets in Iceland / Public fish markets in Iceland - propositions

Why is it not common in Iceland for the public to be able to buy fresh fish on the quayside or at the fish market? Iceland is known for its large and healthy fishing grounds and fish products of high quality. Why not make more of an experience in connection with the fish, both for Icelanders and for tourists? Many people are interested in the idea of a fish market, but for some reason it has not been implemented. These proposals review the status of fish markets in Iceland and what "retail fish markets" can offer. Examples of fish markets abroad are taken, various ways of setting up a retail fish market are reviewed, and the main steps that need to be kept in mind when setting out are reviewed. Finally, an example is taken of the process of original idea work for the establishment of a retail fish market in Reykjavík. The authors hope that this summary will spark interest in and contribute to the establishment of fish markets for the general public across the country.  

There are currently no public fish markets in Iceland - why? Iceland is known for its rich fishing grounds and quality fish products. Why has the seafood experience been more exploited, for the Icelandic public as well as tourists? The idea of a public fish market greatest excitement among most people, however, it has not resulted in an up and running market. In these propositions the current situation in Iceland is reviewed as well as what is to gain by creating and running public fish markets. Examples are taken from fish markets abroad, different scenarios are illustrated and important steps in the preparation process discussed. Finally, example is given on the first steps in idea generation for a public fish market in Reykjavik. The authors aim for these propositions to encourage the establishment of public fish markets all around Iceland. 

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Reports

The value and safety of Icelandic seafood. Food safety and added ranking / Food safety and added value of Icelandic seafood. Risk profiling and risk ranking

Published:

01/05/2007

Authors:

Eva Yngvadóttir, Birna Guðbjörnsdóttir

Supported by:

AVS Fisheries Research Fund and IFL / Matís ohf

The value and safety of Icelandic seafood. Food safety and added ranking / Food safety and added value of Icelandic seafood. Risk profiling and risk ranking

In this project, basic work was carried out on risk assessment for cod, shrimp, redfish, haddock, halibut, herring, saithe and kúfisk. These species were mapped for risk and their risk composition was obtained and a semi-quantitative risk assessment was performed on them. This risk assessment used a calculation model that has been developed in Australia and is called Risk Ranger. The risk assessment used data on consumption habits (dosages, frequency, etc.), frequency and causes of foodborne illness. Thus, the risk associated with the consumption of these marine products was calculated, based on certain assumptions. The reliability of a risk assessment is entirely dependent on the data and information used in its implementation. According to the available measurement data and given assumptions, the above-mentioned seafood products are classified in the lowest risk category (level <32) - low risk, compared to healthy individuals. In international food markets, Icelandic seafood has a good reputation for health and safety. Concerns about food safety, however, are growing in many places, so it is a great challenge for Icelanders to maintain this good reputation in the future.

This report contains the preliminary results of a risk profiling and risk ranking study for the following species: cod (Gadus moruha), shrimp (Pandalus borealis), ocean perch (Sebastes marinus), haddock (Melanogrammus aeglefinus), Greenland halibut (Reinhardtius hippoglossoides) , saithe (Pollachius virens) and Iceland cyprine (Cyprina islandica). These species were surveyed with regard to terms of undesirable substances (Risk profiling and risk ranking, as well as semiquantitative risk assessment). An Australian software, Risk ranger, was used to compute the risk assessment. Various data, eg consumer behavior (daily intake, frequency etc.), and incidence and origin of food-borne diseases, were used. Thus, the risk of consuming these species was determined. The reliability of a risk assessment is dependent on the quality of the data which are used to carry it out. Based on the existing data and given prerequisites, it can be stated that the aforementioned species come under the lowest risk group (degree <32) - small risk, considering healthy individuals. Icelandic seafood products are renowned on the international food markets as being quality and safe food. However, in light of growing concern worldwide for food safety, it is a challenge for Icelandic seafood producers to maintain that good reputation.

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Reports

Nordic information and communication network regarding safety of seafood products. Final Report

Published:

01/03/2007

Authors:

Helga Gunnlaugsdóttir, Björn Auðunsson

Supported by:

NSK (Strategy Reserve), NEF (Nordic Officials' Committee for Fisheries Policy), IFL

Nordic information and communication network regarding safety of seafood products. Final Report

This report is the final report in the Nordic information and communication network project regarding the safety of seafood products, which began in 2005 and was formally completed at the end of 2006. The project developed a joint Nordic website (www.seafoodnet.info) which gathers in one place relevant links containing information on the chemical content of marine products, both undesirable substances and also nutrients. Iceland (first the Fisheries Research Institute and then Matís ohf) was responsible for developing the website and maintaining it, but each country is responsible for its information and for updating it. The project was formally completed at the end of 2006, when the website had just been moved to a new content management system, Eplica, which simplifies all web management and also makes it easier for visitors to find the content they are looking for. It is hoped that these will enable the web to stay "alive" with little effort and cost.

This report is the final report in a Nordic project called “Nordic information and communication network regarding safety of seafood products and utilization of the resources from the sea”. The report contains a summary of the activities in the projects after the 2nd workshop in the project, which was held in Copenhagen, Denmark on April 21st 2006 until the project formally ended at the end of 2006. During this period the website was transferred into a new web content management system called Eplica product suite, which makes administering much easier than in the earlier version and accessing the website much more user-friendly. This was done in accordance with agreements reached at the workshop in Copenhagen. Although the project has formally ended, it is hoped that the seafoodnet.info website will continue to live for some time to come, as a common database or co-ordination of information and reporting of chemical substances, ie nutrients and undesirable substances in seafood. Furthermore, it was hoped that the project would be a cornerstone for further networking and innovative transnational research with the participation of scientists in the Nordic countries and EU.

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