Category: Reports

Reports

Plant raw materials in charr feed instead of fishmeal and fish oil

Published:

01/05/2008

Authors:

Jón Árnason, Ólafur Ingi Sigurgeirsson, Bjarni Jónasson, Helgi Thorarensen, Rannveig Björnsdóttir

Supported by:

AVS

Plant raw materials in charr feed instead of fishmeal and fish oil

The aim of the project was to produce cheap feed for char so that production costs can be reduced and profitability in char farming can be increased. The project consisted of testing different raw materials (especially plant raw materials) instead of fishmeal and fish oil and finding out how large a proportion of them can be in the feed. The condition for success was that the feed was healthy, utilized well by the fish and led to a growth comparable to the current farmed feed and that the feed did not have a negative effect on the quality of the product, in terms of chemical content (fatty acid, color) and physical properties (taste, color, density). Different types of feed were tested as a starter feed for charr juveniles, which is a new approach, in order to get an overview of the possible amount of different raw materials. The most interesting types of feed from those experiments were then tested in experiments on larger chars to confirm the results and to examine the effect on the quality of the products. The results of the experiments with different protein ingredients confirmed that high quality fishmeal (Superior) is a very good source of protein in feed for char. The charr's possibilities of utilizing soybean meal seem to be limited, as in the case of salmon, ie. ≤ 15% incorporation into the feed. The possible use of maize gluten meal appears to be ≤ 18% in starter feeding but could not be tested on larger fish. The reaction of char to rapeseed meal as a protein source, however, was positive and in fact better than expected considering that there has not been a good word for this raw material in feed for other salmonids. Regarding fat sources in charr feed, the results of the project show that different fat sources can be used with acceptable results. Juveniles, on the other hand, seem to have somewhat stricter requirements for fat sources than larger fish. This is especially evident in the effect on growth rate. The results of the experiments with fat sources also show that the composition of the fat source has a decisive effect on the fat composition of the fish as well as various sensory evaluation factors in the product. The main conclusion, however, is that it is possible, within certain limits, to use different fat sources in charr feed. In particular, it seems that palm oil can be used extensively.

The objective of the project was to produce economic feed for Arctic charr to decrease production cost and increase profitability in Arctic charr farming. The project investigated the possibilities of replacing fishmeal and fish oil with raw materials of plant origin, and to find out the limits for their use as feed ingredients. The criteria was that the feed should ensure maximum health, optimize utilization of feed and growth should be comparable to growth obtained by feed currently used. Neither should the feed have adverse effects on product quality, especially regarding fatty acids composition and physical properties (taste, flesh-color, texture). Effect of different raw materials was screened in start feeding trails using Arctic charr larvae. The most interesting raw material combinations were thereafter tested in trials with bigger fish in order to confirm the results of the start feeding trials and investigate the effect of the combinations on slaughter quality of the Arctic charr. The results of the trials with different protein raw materials confirmed that high quality fishmeal (Superior) is a very good protein source for Arctic charr. Arctic charr seems to have limited ability to utilize soybean meal and the inclusion should be limited to ≤ 15% in the diet, similar to the limits that are common for Atlantic salmon diets. The limits for use of Corn gluten meal in starter diets seem to be ≤ 18% but this raw material was not tested in bigger fish. The response of Arctic charr to the use of rapeseed meal as a protein source was positive and even as high inclusion as 30% in the diet did not have negative effect on growth. The main findings of the project regarding use of lipid sources is that it is possible to use different sources with reasonable effect in feed for Arctic charr. Of particular interest is the effect of palm oil. Arctic charr larvae seem to be more demanding, regarding use of lipid sources, than bigger fish. The results clearly demonstrate the effect of fatty acid (FA) composition of the lipid sources on the FA composition of the fish and it is possible to change the FA profile with different lipid sources. Different lipid sources also have marked effects on different sensory traits in the farmed Arctic charr.

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Reports

Fish protein as a dietary supplement

Published:

01/05/2008

Authors:

Guðjón Þorkelsson, Margrét Geirsdóttir, Ragnar Jóhannsson, Sigurður Hauksson, Sjöfn Sigurgísladóttir, Arnljótur Bjarki Bergsson

Supported by:

AVS

Contact

Guðjón Þorkelsson

Strategic Scientist

gudjon.thorkelsson@matis.is

Fish protein as a dietary supplement

The market for food supplements and health products is growing and such products are now a larger part of people's nutrition than before. Dietary supplements are foods that are intended as a supplement to a regular diet. Proteins in supplements and health products are mainly made from milk and vegetable proteins. The nutritional composition of fish proteins is optimal as a dietary supplement, but development and research to produce them with the properties that are considered the most optimal for dietary supplements has been lacking. By processing food supplements from fish, it would be possible to increase the value of the raw material. The aim of the project was to develop fish proteins that were used as dietary supplements. Matís' project network has been built with an emphasis on protein and protein products.

The market for nutritional supplements and health beneficial products is increasing as such products play bigger role in people's nutrition. Nutritional supplements are food products intended as an addition to normal diet. Currently proteins in the aforementioned products are mainly processed soy proteins. Fish proteins contain many promising nutritional qualities, but development and research on producing them with the most favorable attributes have not been completed yet. If it were possible to produce nutritional supplements from fish, the catch value could be increased. The aim of this project was to develop fish proteins that could be used as food supplements. On the basis of the project a network of various projects with emphasis on protein and protein products of fish origin has been established at Matís.

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Reports

Fish protein markets. Analysis of products on the market

Published:

01/04/2008

Authors:

Guðjón Þorkelsson, Þóra Valsdóttir, Guðrún Anna Finnbogadóttir, Sigrún Mjöll Halldórsdóttir

Supported by:

AVS

Contact

Guðjón Þorkelsson

Strategic Scientist

gudjon.thorkelsson@matis.is

Fish protein markets. Analysis of products on the market

The report begins with a general description of proteins in the food market, ie. different types of proteins and market share. The main products with fish proteins are also described, i.e. fishmeal, fish protein concentrate, surimi, isolati, fish digestion, fish sauce, flavors, gelatin, dietary supplements and their health-related properties. Targeted diet with soy, milk and fish proteins is described. The main conclusions about the position of fish proteins in this market are: The use of protein isolates in injected and tumbled products will increase the economic, nutritional and environmental value with better utilization of raw materials in fillet processing. Also in the production of prepared seafood. There are still many problems that need to be solved. It would be possible to achieve considerably more value if it were possible to produce high-quality isolates from fatty pelagic fish. Despite indications of various excellent processing properties of fish proteins, methods of isolation and purification are less advanced than for vegetable and milk proteins. They can not compete with them as excipients in prepared foods. However, there is a good chance of developing more supplements from hydrolyzed fish proteins (VFP), for example to reduce blood pressure or to increase the body's protection against stress. Certain protein products can even be used to control appetite in the fight against obesity. In addition, there are products on the market to lower the glycemic index. The market for such fish protein products is not large but is likely to grow, and there are opportunities to use traditional production methods such as fermentation to increase the bioactivity properties of VFP and use them in products known to consumers. It is very likely that low-salt fish sauces and fish flavors with specially designed bioactive properties will be on offer in the future. However, this is partly due to the fact that the health claims are accepted. This requires extensive and costly research that will require both public bodies and companies to pay for.

A short overview is given for products and the market for food protein ingredients. The main types of fish protein products are described, that is, fish meal, fish protein concentrate and isolate, surimi, fish silage, fish sauce, fish flavors and gelatine. Food supplements with soy, dairy and fish proteins or peptides and their health-related properties are covered. The main conclusions for the future outlook for fish protein and peptide products are: Applying protein isolates as water binders in injected and tumbled products will result in greater additional economic, nutritional and environmental values by increasing the yield of raw materials in fish filleting operation and by using them in production of ready-to-eat seafood products. There would be an even greater economic advantage if pH-shift methods could be used to produce high-quality isolates from raw material that today is unfit for traditional processing. Fish protein ingredients cannot compete on price, size and quality with plant and dairy proteins on the functional ingredient market. Plant and dairy ingredients will continue to be a part of formulating ready-to-eat convenience fish products. More supplements from FPH can be developed to reduce high blood pressure but they will face heavy competition from other protein sources. The antioxidant properties of FPH can be employed in supplements and food products to enhance the antioxidant defenses of the body against oxidative stress. They can also be used as immunomodulators to enhance non-specific host defense mechanisms. Specific protein products can even be made to control food intake in the fight against obesity. The market for such products made from fish proteins is not big but it will grow and there are also opportunities for adapting traditional food processes like fermentation to enhance the bioactive properties of FPH and to use them in products that consumers already know. Low-salt fish sauce and fish flavors with tailor-made bioactive properties are likely the future. Sufficient scientific evidence must be produced if companies are to produce and sell products with health claims. Private companies, universities and other research organizations can work together on special hydrolysates or peptides but the cost might be too high for small companies, so a global collaboration may be needed in the interests of fisheries, fish processing industries and consumers worldwide.

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Reports

Oxidation in fish muscle - The role of phospholipids, proteins, antioxidants and the effect of boiling on oxidation in fish muscle

Published:

01/04/2008

Authors:

Rósa Jónsdóttir, Margrét Bragadóttir, Guðrún Ólafsdóttir

Supported by:

RANNÍS Research Fund

Contact

Rósa Jónsdóttir

Research Group Leader

rosa.jonsdottir@matis.is

Oxidation in fish muscle - The role of phospholipids, proteins, antioxidants and the effect of boiling on oxidation in fish muscle

The aim of the project was to increase the understanding of the effects of oxidation in fish muscles, which reduces the taste and nutritional value of fish. The effects of added natural antioxidants or antioxidants were assessed to improve the stability of fish products and thus increase the possibility of using fish in prepared dishes. A phospholipid model from cod was used to examine the effects of stimulants (hemoglobin from cod and char) and inhibitors in the liquid phase from capelin and Icelandic algae. The effect of boiling and added anti-corrosion substances on the taste properties and the formation of a so-called heating taste in boiled fish mince was also examined. The effect of oxidation on membrane phospholipids and proteins in the fish muscle model and in the fish mince during heating and storage was measured by sensory evaluation, color measurements, conventional evolution measurements (TBA), gas spectrometry measurements to identify volatile odorants and electrophoresis capillary capillary peptile and amino acids that affect taste and bioactivity. The relationship between these factors was examined to explain and better understand the oxidation process in fish muscles and the factors that limit the shelf life of prepared fish products. The main negative effects of oxidation on fish quality were the formation of odorants, mainly aldehydes, which are fatty acid degradants. Membrane fat in lean fish can therefore have a significant effect on the taste quality of prepared foods, despite being in small quantities. Oxidative stimuli such as blood in the flesh and boiling led to faster oxidation, which shows that with proper bleeding and mild heat treatment, oxidation could be limited and the taste quality of fish could be better maintained. In addition, oxidation can be reduced through the use of antioxidants. Measurements of the antioxidant activity of capelin broth in a fish muscle model showed that variable external factors such as seasonal fluctuations and the treatment of capelin raw material can affect the antioxidant activity. A novelty in this project is a basic study of the effects of capillaries and algae, as well as changes in the decomposition products during welding, which have a direct effect on the taste quality of the product. Research in this area is being continued in new projects that focus on better looking at natural antioxidants from capelin and algae, as well as their health-promoting effects.

The aim of the project was to study the effect of heating on oxidation of phospholipids, and the role of antioxidants in fish muscle to influence sensory quality and nutritional value. A phospholipid model from cod was used to study the effect of pro-oxidants (hemoglobin from cod and trout) and antioxidants in aqueous fraction of capelin and in seaweed extracts. The effect of heating and the addition of antioxidants on the sensory quality and the development of warmed-over-flavor (WOF) in fish mince were also studied. The development of degradation compounds in washed cod model system during storage and heating was studied by sensory analysis, color measurements, traditional lipid oxidation analysis (TBA) and gas chromatography analysis to identify volatile compounds. Capillary electrophoresis (CE) was applied for the analysis of peptides and amino acids that influence the sensory quality and bioactivity. The correlation between these analyzes was studied to better understand the oxidation processes in fish muscle and to explain factors reducing the shelf life of ready-to-eat fish products. Quality defects related to oxidation of polyunsaturated fatty acids and formation of volatile compounds like aldehydes contributing to rancidity and color changes were enhanced by pro-oxidative effects of blood and cooking. Membrane bound phospholipids are therefore of concern as precursors for off flavor and quality defects in lean fish despite of low fat content. Capelin broth appeared to have antioxidant effects in fish model system whereas press juice from whole capelin exhibited pro-oxidant effects. The outcome of this project is increased knowledge on oxidation in fish muscle to underpin the development of healthy and tasteful fish products of high sensory quality and nutritional values fulfilling the needs of consumers. Continued studies have been established in new projects to further characterize the antioxidant properties and possible health effects of capelin and seaweed extracts.

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Reports

Comparison of insulation of tanks with experiments and heat transfer models

Published:

01/04/2008

Authors:

Björn Margeirsson

Supported by:

Promens Dalvík ehf, Matís ohf

Comparison of insulation of tanks with experiments and heat transfer models

The aim of the project was to investigate the insulation value of three types of fish tanks. The pots were either insulated with polyethylene or polyurethane foam and of two sizes, 400 and 460 L. In two experiments, the temperature rise of water in the pots was monitored with a time with the initial temperature of the water approx. 4 ° C and ambient temperature approx. 18-20 ° C. The increase in temperature was also assessed using computerized heat transfer (CFD) models. The effect of forced airflow around the pot (forced heat transfer) was assessed by comparison with the heat condition in free heat transfer (in heat). The study showed that there is a considerable difference in the insulation of different pots and the pots came out differently depending on whether it was free or forced heat transfer. The results of measurements and heat transfer models for calm pots were well matched, but the model for wind pots needs to be improved. In further research into the insulation value of the pots, frozen fish should be used instead of water to further mimic the actual situation.

The aim of the project was to investigate the insulation capability of three types of fishing tubs. The tubs were either insulated with polyethylene or polyurethane foam and of two sizes; 400 and 460 L. In two experiments water temperature inside the tubs was monitored with initial water temperature ca. 4 ° C and ambient temperature ca. 18-20 ° C. The water temperature was also simulated in computational fluid dynamics models (CFD models). Influence of forcing air flow around the tubs (forced convection) was evaluated by comparison to free convection. Considerable difference was found between insulation capabilities of the different fishing tubs. Forced convection had different effects on different tub types. A good congruity was between experimental and CFD results for tubs in no wind, but some improvements should be done for the CFD model for tubs in wind (forced convection). In further research on insulation capability of the tubs iced fish should be used instead of water in order to resemble practical situations.

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Reports

Blue whiting as a target food

Published:

01/03/2008

Authors:

Margrét Geirsdóttir, Ragnar Jóhannsson

Supported by:

Rannís

Contact

Margrét Geirsdóttir

Project Manager

mg@matis.is

Blue whiting as a target food

The aim of the project was to answer the research question: What bioactivity can be obtained from peptides extracted from blue whiting with enzymes? Bioactivity is a prerequisite for the use of blue whiting as a target food. Isolated blue whiting proteins were used as raw materials. The study showed that degraded blue whiting proteins have bioactivity. However, the sensory properties of products did not prove to be good enough and yields were low. This was especially so due to the difficulty of obtaining fresh blue whiting as a raw material. In the second steps of the project, it was decided to use cod. The aim was to investigate in particular whether isolated cod proteins had other properties than hacking in terms of sensory evaluation and antihypertensive properties of products. The result was that no differences in these characteristics were found in the study. The project investigated the interaction of hydrolysis with enzymes and processing properties and bioactivity. The interaction of hydrolyzed blue whiting proteins isolated by a new method and their bioactivity has not been performed before and was an international novelty. The project acquired extensive knowledge in the field of enzyme degradation and the bioactivity properties of protein products.

The aim of the project was to answer the question: What kind of bioactive properties do peptides produced by enzyme hydrolysis of blue whiting have? Some sort of bioactivity is needed if they are to be used in functional food. The substrate for the hydrolysis was isolated blue whiting proteins. Well-known, commercially available enzymes were used to hydrolyze the proteins to different degrees of hydrolysis (%DH). The blue whiting hydrolysates showed bioactive properties, but their sensory characteristics were not good. Furthermore, the yield of the process was low. The reason for this was a shortage of fresh raw material. Thus, in the next steps cod was therefore used. The main aim was to study whether different sensory and bioactive characters were achieved when isolated proteins were used compared to mince. The results of the project indicate that there is no difference. In the project the connection between enzyme hydrolysis and functional and bioactive properties was examined. Main emphasis was on the effect of using isolated proteins as raw material for enzyme hydrolysis. In the project important knowledge in the field of enzyme hydrolysis and bioactivity was gained that will facilitate future research.

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Reports

Biodiversity in the hot springs at Krafla and Námafjall

Published:

01/02/2008

Authors:

Sólveig K. Pétursdóttir, Snædís Björnsdóttir, Sólveig Ólafsdóttir, Guðmundur Óli Hreggviðsson

Supported by:

National Energy Authority

Contact

Guðmundur Óli Hreggviðsson

Strategic Scientist

gudmundo@matis.is

Biodiversity in the hot springs at Krafla and Námafjall

This study of ecosystems in hot springs in the thermal areas at Krafla and Námafjall is the fourth phase of the project on ecosystems in thermal areas in Iceland, which is part of the Framework Plan for the utilization of hydropower and geothermal energy in high-temperature areas. Results from similar studies in the Hengill area (2005), Torfajökull area (2006) and Krísuvík (2007) have already been submitted. A total of about 20 samples of liquid, soil or biomass were taken and the species composition was analyzed in 13 of them by partial differentiation of 16S rRNA. The predominant species in the Krafla samples were primitive and chemically active of the divisions Aquificae and β-Proteobacteria. Samples from Jarðbaðshólar were more diverse and were divided into the divisions Actinobacteria, Acidobacteria, Firmicutes, photosynthetic Cyanobacteria and Deinococcus-Thermus. Given the diversity of samples and sampling sites, it was not surprising that species composition varied. Most of the species found are also found in other hot springs in the world. New bacterial species were found in several samples, including the primitive Hydrogenobacter species in a sample from wastewater from a separation station at Krafla. In addition, two new species of β-proteobacteria were found. Three new species of γProteobacteria were found, one in Grjótagjá, another in a soil sample by the steam eye in Jarðbaðshólar and the third in a drainage stream in Krafla. A new species of the Meiothermus genus was found in Jarðbaðshólar and finally one distant (92%) Thermus species. One closely related species (≥98%) species Thermus aquaticus was found in a sample of the Krafla area, but this species has been considered endemic in the United States. Biodiversity in the samples was estimated to be in the range of 1.0 - 5.8 on a scale of 1-10, but it is common for the value to be in the range of 1-2 in samples from peripheral ecosystems where the environmental impact is high. The value was very low in several samples in the study, or 1.04 in a soil sample from Suðurhlíðar Krafla, 1.2 in a liquid sample from a drainage stream in Krafla, 1.0 in a clay spring at Víti and 1.1 in a liquid sample from the Blue Lagoon in Bjarnarflag. Biodiversity was considerably higher in samples from Grjótagjá (3,4) and Jarðbaðshólar (4,8-5,2), which is not surprising as environmental conditions were more favorable for more species. Hot water samples were scanned for 72 elements (ICP_MS). It is hoped that in the future it will be possible to link elemental measurements with results from species composition in samples.

This project on microbial diversity in hot springs in the Krafla and Namafjall geothermal areas is within the Framework of Utilization of Geothermal power of high temperature geothermal areas in Iceland. Other areas studied so far are the Hengill area (2005), Torfajökull area (2006) and Krísuvik area (2007). Twenty samples were taken from liquid, soil or biomass. Partial sequencing of 16S rRNA genes from the samples was used to estimate species composition in the samples. Species composition was estimated in 13 samples. Dominating species within the Krafla samples were chemolithoautotrophic species of Aquificae and β-Proteobacteria phyla. In Jarðbaðshólar samples, the species were more diverse and belonged to the Actinobacteria, Acidobacteria, Firmicutes, Cyanobacteria and Deinococcus-Thermus phyla. This was not surprising as sample types and sample sites were diverse in character. Most species found in this study were known from other geothermal areas in the world. Novel species were found in several samples: A chemolithoautotrophic Hydrogenobacter species was found in an effluent from the powerplant in Krafla. Two new species of β-Proteobacteria were also found in the samples. Three novel species of γ-Proteobacteria were found, one in Grjótagjá, one in Jarðbaðshólar and one in the Krafla effluent. A novel species of the genus of Meiothermus was found in Jarðbaðshólar. Finally one species, a distant (92%) relative of Thermus spp. A close (≥ 98%) relative of Thermus aquaticus was found in one sample from the Krafla area, but this species has hitherto been confined to the USA. A biodiversity index of the samples was calculated between 1.0-5.8, but a value of 1-2 is common in samples from extreme ecosystems were environmental pressure is high. This value was quite low in several samples ie 1,04 in a soil sample from the southern hills of Krafla, 1,2 in a liquid sample from the Krafla effluent, 1,0 in a geothermal mudsample from Víti and 1,1 from a liquid sample from the Blue Lagoon in Bjarnarflag. Calculated biodiversity index in samples from Grjótagja and Jarðbaðshólar was considerably higher which is not surprising as environmental conditions were favorable to a higher number of species. Water samples from hot springs were scanned semi quantitatively for 72 elements and analyzed with ICP-MS. In the future we hope to be able to connect data from element analysis to results of species composition.

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Reports

QALIBRA - Cluster Meeting Report and Minutes from the 2nd Cluster meeting of the QALIBRA and BENERIS projects

Published:

01/02/2008

Authors:

Helga Gunnlaugsdóttir, Björn Þorgilsson

Supported by:

European Commission, Matís, CSL, RIVM, WU, Upatras, Altagra, Ipimar

QALIBRA - Cluster Meeting Report and Minutes from the 2nd Cluster meeting of the QALIBRA and BENERIS projects

This project report describes a joint meeting of two European projects called QALIBRA and BENERIS. The meeting was held in Helsinki, Finland from 6 to 9 November 2007. Both projects fall under Priority 5, Food Quality & Safety in the 6th EU Research Program and share some work components. The purpose of the meeting was:

1) Audit of two EU regulators on the work of the projects for the first 18 months

2) Ensure the flow of information between projects and discuss ongoing collaboration

3) Comments and proposals of the reference advisory committee of the projects on the work and the continuation

QALIBRA, or “Quality of Life - Integarted Benefit and Risk Analysis. Web-based tool for assessing food safety and health benefits, ”abbreviated QALIBRA (Heilsuvogin in Icelandic), is a three-and-a-half-year project led by Matís. The project manager is Helga Gunnlaugsdóttir, department manager at Matís. The aim of the QALIBRA project is to develop quantitative methods to assess both the positive and negative effects of food ingredients on human health. The goal is to present these methods in a computer program that will be open and accessible to all stakeholders on the web. The aim of the BENERIS project is to create a methodology for dealing with complex benefit-risk situations, and then use them to assess the benefits / risks that certain types of food can bring. The first type of food that will be used in the development of this methodology is seafood. This report describes the discussions and the main conclusions of the meeting.

This report is a summary of the 2nd Cluster meeting of the QALIBRA and the BENERIS projects in Helsinki, Finland, November 6-9th, 2007. Both projects are funded by the EC´s 6th framework program, and have the same contract starting dates and a common workpackage (WP6) for cluster activities. Both projects began on April 1st 2006 and will run until October 2009, or for 42 months. This report contains results of the discussions that took place and the actions defined, while the overheads presented during the meeting are compiled in an Annex to the report. The overall objective of QALIBRA is to develop a suite of quantitative methods for assessing and integrating beneficial and adverse effects of foods and making them available to all stakeholders as web-based software for assessing and communicating net health impacts. The overall objective of BENERIS is to create a framework for handling complicated benefit-risk situations and apply it for analysis of the benefits and risks of certain foods. The first food commodity to be used in the development of the methodology is seafood.

The objective of the Cluster meeting was:

1) Evaluation (by two independent experts appointed by the EC) of activities from the beginning of the projects until the meeting

2) Sharing of information on scientific progress and plans between Qalibra and Beneris, as well as planning of further cluster activities

3) Obtain feedback and advice from the Qalibra / Beneris Scientific Advisory Panel (SAP)

This report contains results of the discussions that took place and the actions defined.

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Reports

Genetics kit for char

Published:

01/02/2008

Authors:

Sigurlaug Skírnisdóttir, Alexandra M. Klonowski, Sigurbjörg Hauksdóttir, Kristinn Ólafsson, Helgi Thorarensen, Einar Svavarsson, Sigríður Hjörleifsdóttir

Supported by:

Tækniþróunarsjóður Rannsóknamiðstöð Íslands

Contact

Sigurlaug Skírnisdóttir

Project Manager

sigurlaug.skirnisdottir@matis.is

Genetics kit for char

The goal of the project was to create a powerful genetic kit for char with 15-20 genetic markers. Many genetic markers have been published for char and other salmonids, but the disadvantage is that no suitable reproduction gene set is known, which is a prerequisite for the efficient use of technology. It is important that the genetic markers show variability within the strain, are of a certain size but of different sizes, work well in a amplification reaction solution and are well readable after the sample has been run on a sequencer. The risk in the project was whether it would be possible to find a suitable genetic marker that could be combined into 2-3 reaction mixtures. 70 pairs of indicators were tested for 56 published genetic markers. The result of the project was that it was possible to combine 17 genetic markers into 3 reaction mixtures. A total of 140 fish were identified from the Hólar fish stock with these 17 genetic boundaries, but in addition, 12 wild fish were identified with them. The results showed that the genetic markers were used to differentiate between different groups of char. The processing of genetic analyzes clearly confirmed that Hólableikjan is mainly made up of two species. Some genetically modified wild charr yielded new isotopes not seen in farmed fish. Therefore, there are now genetic marketing kits that can be used in breeding work, in stock research on wild char and in traceability research. This will strengthen breeding work and is a powerful tool for research on char in the future.

The goal of the project was to develop genotyping protocols for Arctic charr containing multiplexes of 15-20 microsatellite markers. Many microsatellite markers have been published for salmonoid fishes, but no multiplexes are known which are of practical use when analyzing many samples at a time and therefore, to make the research profitable. The microsatellite markers must show variability among the fishes, they must be of certain sizes and of variable sizes, they must be amplifiable in multiplex PCR reactions and they must be easily readable from the machine. The risk of the project was to find published microsatellite markers which would fulfill these criteria and fit into 2-3 multiplex PCR reactions. Seventy primer pairs were tested for 56 published microsatellite markers. The results of the project were that 17 microsatellite markers which fit into 3 multiplex PCR reactions. A total of 140 fish from the brood stock of Arctic charr from the University at Holar was analyzed in the study as well as 12 samples from wild fish of different lakes and rivers. The results indicate that these markers can be used to analyze different stocks of Arctic charr. Furthermore, analyzes of the brood stock confirms that it mainly consists of two different stocks. New alleles were observed in the wild fish compared to the brood stock fish. A genotyping protocol to analyze Arctic charr for use in breeding industry, in wild fish research and in tractability analyzes, is now available. This will help in building up breeding programs and will be a helpful tool of the genetic research of Arctic charr.

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Reports

Formation of acrylamide in food

Published:

01/01/2008

Authors:

Ólafur Reykdal, Irek Klonowski

Supported by:

Nordic Innovation Center (NICe)

Contact

Ólafur Reykdal

Project Manager

olafur.reykdal@matis.is

Formation of acrylamide in food

In the years 2004-2007, Icelanders took part in a Nordic project on the formation of acrylamide (Akrylamide - Precursors: Limiting substrates and in vivo effects). was tested in baking products and it did not affect the formation of acrylamide. Acrylamide in french fries varied considerably, but at the end of the project it was low after pre-frying in a factory.

Icelandic food scientists and companies participated in a Nordic project on acrylamide (Akrylamide - Precursors: Limiting substrates and in vivo effects) in 2004 - 2007. The formation of acrylamide was investigated in cereal- and potato products and data on the precursors of acrylamide, sugars and amino acids, were collected. Icelandic barley flour was used in bakery products and did not influence the formation of acrylamide. Insubstantial acrylamide formed in the traditional Icelandic bakery products flat bread and thin unleavened wheat bread. Acrylamide was not detected in several types of bread, but quite high levels of acrylamide were found in sweetened rye bread which is baked for a long time. Acrylamide in french fries proved variable but moderate levels were found in 2006 after first frying in factory. The levels of acrylamide depend very much on the second frying at home.

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