Reports

Minimizing spoilage in lobster with enzyme inhibition and hypothermia / Minimizing spoilage in Nephrops in Iceland

Published:

01/09/2011

Authors:

Guðmundur Gunnarsson, Aðalheiður Ólafsdóttir, Heiða Pálmadóttir, Páll Steinþórsson, Vigfús Ásbjörnsson

Supported by:

AVS Fisheries Research Fund

Contact

Aðalheiður Ólafsdóttir

Sensory evaluation manager

adalheiduro@matis.is

Minimizing spoilage in lobster with enzyme inhibition and hypothermia / Minimizing spoilage in Nephrops in Iceland

The purpose of this project was to maximize the activity of enzyme inhibitors (hasenose) with high subcooling to reduce myocardial infarction in lobster off Iceland. The effect of enzyme inhibitors on the quality aspects of lobster was assessed. The activity of different refrigerants on board fishing vessels during lobster fishing. The product of the project is then a definition of a processing process for the lobster industry with the use of enzyme inhibitors and high subcooling.

The aim of this project was to maximize the effects of using food grade protein inhibitor (EDTA) with combination of effective ice / seawater cooling to minimize muscle spoilage in nephrops in Iceland. To analyze different effects on nephrops quality factors when using the food grade protein inhibitor (EDTA) and to measure the effects of using different cooling media. The end product of this project is a simple code of practice information for the lobster industry in Iceland on how to use the combination of the food grade protein inhibitor (EDTA) with different cooling media to get the most effects on reducing muscle spoilage in nephrops in Iceland.

Report closed until 01.09.2013

View report

Reports

Effect of cooling and packaging methods on the quality deterioration of redfish fillets

Published:

01/09/2011

Authors:

Hélène L. Lauzon, Aðalheiður Ólafsdóttir, Magnea G. Karlsdóttir, Eyjólfur Reynisson, Björn Margeirsson, Sigurjón Arason, Emilía Martinsdóttir

Supported by:

EU IP Chill ‐ on (contract FP6‐016333‐2)

Contact

Aðalheiður Ólafsdóttir

Sensory evaluation manager

adalheiduro@matis.is

Effect of cooling and packaging methods on the quality deterioration of redfish fillets

The aim of the experiment was to evaluate the effect of slush ice cooling after filleting and / or packing in vacuum packaging on the deterioration of the quality of fresh redfish fillets. The fillets were stored at -1 ° C for 6 days to simulate well-executed sea transport in foam plastic boxes and then at 2 ° C, as happens after delivery abroad and storage in retail. Product and ambient temperature were monitored from packaging and sensory evaluation, microbial and chemical measurements were performed. The fish was caught in the spring and processed 6 days after fishing. The results show that the quality of the raw material was not the best during packaging as the development process (PV and TBARS) was well underway. This probably explains why none of these refrigeration methods led to an increase in shelf life. It was also found that there was no benefit in cooling the fillets unprotected in slush ice as the microbial growth and formation of TVB-N and TMA in the fillets was faster with further storage. However, it seems preferable to refrigerate vacuum packed fillets in ice cream as this method has led to slower growth of pest microorganisms, lower TMA levels and a slower development process. Photobacterium phosphoreum is important in the process of damaging fresh redfish fillets, regardless of the packaging method.

The aim of this study was to evaluate the effect of slurry ice cooling in process (post ‐ filleting) and packaging method (+/‐ oxygen) on the quality deterioration of skinned redfish fillets during storage in expanded polystyrene boxes simulating well ‐ performed sea freight transportation (6 days at ‐1 ° C) followed by storage at the retailer (2 ° C). Also, to assess the use of vacuum ‐ packaging to protect the fillets from direct contact with the cooling medium (slurry ice) and to achieve superchilling following extended treatment. Temperature monitoring as well as sensory, chemical and microbial analyzes were performed. The fish was caught in the spring and processed 6 days post catch. The results show that quality of the fillets was not optimal at packaging, due to the detection of primary and secondary oxidation products. This may have been the reason why shelf life extension was not achieved by any of the methods evaluated. Further, there was no advantage of cooling the fillets unpacked since this method stimulated microbial growth and formation of basic amines. On the other hand, slurry ice cooling of vacuum ‐ packaged fillets led to a slower microbial development, the lowest TMA level and delayed autoxidation. Finally, the importance of Photobacterium phosphoreum in the spoilage process of redfish fillets, independently of the packaging method, was demonstrated.

View report

Reports

Undesirable substances in seafood products - results from the Icelandic marine monitoring activities in the year 2010

Published:

01/09/2011

Authors:

Vordís Baldursdóttir, Natasa Desnica, Þuríður Ragnarsdóttir, Helga Gunnlaugsdóttir

Supported by:

Ministry of Fisheries and Agriculture

Undesirable substances in seafood products - results from the Icelandic marine monitoring activities in the year 2010

In 2003, at the initiative of the Ministry of Fisheries, monitoring of undesirable substances in marine products, both for human consumption and products for the fish oil and flour industry, began. Matís has been entrusted with the supervision of the monitoring project. The purpose of the monitoring is to assess the condition of Icelandic marine products with regard to the amount of contaminants. The aim is also to collect independent scientific data on undesirable substances in marine products for the government, the fishing industry as well as buyers and consumers of Icelandic seafood. The data collected in the monitoring project will also be used in risk assessment and to build up a database on contaminants in the Icelandic ecosystem. Coverage of contaminants in marine products, both in the mainstream media and in scientific journals, has many times demanded the response of the Icelandic government. It is necessary to have scientific results available that demonstrate the actual condition of Icelandic seafood in order to prevent damage that may result from such coverage. Furthermore, the limits of contaminants are under constant review and it is important for Icelanders to participate in such a review and support their case with scientific data. This shows the importance of regular monitoring and that Iceland conducts independent research on such an important issue as marine product pollution. This report is a summary of the results of the monitoring for the year 2010. Assessment of the state of Icelandic marine products with regard to contaminants is a long-term project and will only be carried out through continuous monitoring. Every year, therefore, the missing data is carefully reviewed, thus aiming to fill in the gaps. In 2010, the following substances were measured in marine products intended for human consumption as well as products for the fish oil and flour industry: dioxins, dioxin-like PCBs and pointer PCBs, PBDEs, metals, as well as 12 different types of pesticides. A special effort was made to measure PBDEs and metals in 2010 and their concentration was generally low in Icelandic seafood. As before, a small amount of undesirable substances was generally measured in Icelandic seafood in 2010. Oil and flour made from blue whiting, however, have to be close to or above the permitted limits for certain substances.

This monitoring of undesirable substances in seafood products was initiated by the Icelandic Ministry of Fisheries and Agriculture in the year 2003. Until then, this type of monitoring had been limited in Iceland. Matis was assigned the responsibility of carrying out the surveillance program, which has now been ongoing for seven consecutive years. The purpose of the project is to gather information and evaluate the status of Icelandic seafood products in terms of undesirable substances. Further, the aim of the project is to provide independent scientific data on undesirable substances in Icelandic seafood for food authorities, fisheries authorities, industry, markets and consumers. The information will also be utilized for a risk assessment and gathering of reference data. This report summarizes the results obtained in the year 2010 for the monitoring of various undesirable substances in the edible part of marine catches, fish meal and fish oil for feed. The monitoring began in 2003 and has now been carried out for seven consecutive years. The evaluation of the status of the Icelandic seafood products in terms of undesirable substances is a long term project which can only be reached through continuous monitoring. For this reason, we carefully select which undesirable substances are measured in the various seafood samples each year with the aim to fill in the gaps in the available data. Thus the project fills in gaps of knowledge regarding the level of undesirable substances in economically important marine catches for Icelandic export. In the year 2010, data was collected on dioxins, dioxin-like PCBs, marker PCBs, 12 different types of pesticides, PBDEs and trace metals in the edible part of fish, fish oil and meal for feed. Samples collected in 2010 generally contained low concentrations of undesirable substances. These results are in agreement with our previous results obtained in the monitoring programs in the years 2003 to 2009. In the year 2010 emphasis was placed on gathering information on the organic compounds PBDEs and inorganic trace elements in the edible part of marine catches as well as in the fish meal and fish oil for feed. The results reveal that the concentrations of PBDEs compounds are in low in fish and fish products for feed. Blue whiting meal and oil can contain undesirable substances in concentration close to or exceeding the maximum level set by the EU.

View report

Reports

Thermal modeling of processing and transport of fresh fish / Hermun kæliferla - LOKASKÝRSLA

Published:

01/09/2011

Authors:

Björn Margeirsson, Sigurjón Arason, Kristín Valtýsdóttir

Supported by:

AVS Fisheries Research Fund, Technology Development Fund, University of Iceland Research Fund

Contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Thermal modeling of processing and transport of fresh fish / Hermun kæliferla - LOKASKÝRSLA

The main objective of the project Simulation of cooling processes - thermodynamic simulation of production and transport processes, which began in June 2008, was to present improvements in procedures and equipment related to the transport of marine products through process analysis, experiments and computerized thermal and hydrological models. The consequences of improved temperature control in production and transport processes are increased quality, stability and safety, which at the same time increase the value of the product. Partners in the project were Matís, the University of Iceland, Promens Tempra, Eimskip Ísland, Samherji, Brim (ÚA), Festi, Völusteinn and Eskja. This report describes the main results and products of the project. Examples of products are heat transfer models of fresh fish products in a foam box, which make it possible to predict fish temperatures based on environmental temperature history. Heat transfer models were used to redesign the Promens Tempra 3, 5 and 7 kg foam boxes with the minimum target fish temperature minimization under the target heat load. Experiments confirmed the superiority of the new boxes over traditional box types, both in terms of temperature control and product quality under heat load. The results of another experiment show that the shelf life of fresh fish fillets in corner boxes of whole pallets in the air transport chain can be about 1-1.5 days shorter than fillets in boxes in the middle of the pallet stack. Heat distribution in different cooling chains was mapped and special emphasis was placed on pre-cooling fillets for packing and heat distribution in different types of cooling containers with different loading patterns. 

The main aim of the research project Hermun kæliferla - Thermal modeling of processing and transport of fresh fish, which was launched in June 2008, was to improve technology and practices used for fish processing and transport by means of analysis of chill chains, experiments and computational modeling. Improved temperature control in fish chill chains leads to increased product quality, stability and safety and thereby increased product value. This report describes the main results and products of the project. Examples include heat transfer models of fresh fish fillets packaged in boxes, which can be used to predict product temperature evolution as a function of variable ambient temperature. Numerical heat transfer models were used to optimize the design of 3, 5 and 7 ‐ kg expanded polystyrene boxes manufactured by Promens Tempra with the aim of minimizing the maximum fish temperature in boxes under thermal load. Improved thermal protection of the new box design was confirmed in different experiments, both with regard to lesser product temperature variations and extended freshness period and storage life of products. The results from another storage study suggest that the storage life of fresh fish products in a corner box can be more than 1‐1.5 days shorter than in the center boxes of a full size pallet stack in a real air transport chain, depending on the level of ambient thermal load. Environmental and product temperatures were mapped in different chill chains with special emphasis laid on precooling during processing and temperature distribution in reefer containers of different types and loading patterns. 

View report

Reports

Utilization of raw materials from the plant and animal kingdom in fish feed

Published:

10/07/2011

Authors:

Ásbjörn Jónsson, Jón Árnason, Ragnheiður Þórarinsdóttir, Sjöfn Sigurgísladóttir

Supported by:

Vocational Training Fund of the Ministry of Social Affairs and Social Security

Utilization of raw materials from the plant and animal kingdom in fish feed

Feed costs in aquaculture are generally around 50‐70% of operating costs and a large proportion of raw materials in feed are imported. The purpose of this report is to compile information on the possibility of utilizing domestic raw materials used in agriculture and fisheries for aquaculture feed. It is considered that the raw materials are generally used for aquaculture and the summary is not limited to individual species. It is possible to use by-products from the fisheries sector as feed in aquaculture, but by-products from the plant kingdom need to be treated in order to reduce / eliminate a high proportion of fiber and increase the protein content. By-products of the plant kingdom may be used as food for invertebrates, bacteria and fungi, thus producing a protein-rich product suitable for fish feed.

Feed cost in aquaculture is about 50‐70% of the total cost, and most of the feed is imported. The aim of this report is to gather information about utilizing by-products from agriculture and fishing industry as a feed in aquaculture. By-products from the fishing industry can be used as feed in aquaculture but it is necessary to lower the level of fiber and increase protein in by-products from agriculture. This can possibly be done by using the by-products as feed for invertebrates, bacteria and mushrooms and produce protein rich feed for aquaculture.

View report

Reports

Biodiesel from photosynthetic organisms / Biodiesel from photosynthetic organisms

Published:

01/07/2011

Authors:

Sólveig K. Pétursdóttir, Guðmundur Óli Hreggviðsson

Supported by:

Reykjavík Energy's Environment and Energy Fund (UOOR)

Contact

Guðmundur Óli Hreggviðsson

Strategic Scientist

gudmundo@matis.is

Biodiesel from photosynthetic organisms / Biodiesel from photosynthetic organisms

The aim of the project was to isolate and cultivate photosynthetic microorganisms that can utilize greenhouse gases from the emissions of geothermal power plants, ie. hydrogen sulphide (H2S) and carbon dioxide (CO2), while delivering usable products that could potentially be used in biodiesel and feed. Two groups were mainly examined: First, photosynthetic bacteria that utilize H2S and bind CO2 but do not tolerate oxygen (anoxygenic). Second, photosynthetic algae that bind carbon from carbon dioxide and release oxygen (oxygenic). The project was planned to take two years and received funding from UOOR until the previous year. Attempts to isolate and cultivate photosensitive, H2S-utilizing, CO2-binding bacteria were unsuccessful, so the research material was mainly microalgae and bluish-green bacteria that were isolated in the vicinity of geothermal power plants. Species found were 31 in total and the populations grew at different temperatures. Growth rate (g / L / day) was estimated for institutions and also their pigment content (chlorophyll and carotene). The "Nile Red" method for estimating the fat content of microalgae and bluish-green bacteria was tested on several strains, but requires a method development that is planned for the second year of the project. Further attempts to isolate photosensitizing bacteria using H2S are also on the agenda for later years.

The aim of the project was to isolate and cultivate photosynthetic microorganisms able to utilize emission gases from geothermal power plants, ie hydrogen sulfide (H2S) and carbon dioxide (CO2) and return products which may be used in biodiesel production and feed. Two groups were of particular interest: First, anoxygenic, photosynthetic bacteria utilizing H2S and assimilating CO2; and second, oxygenic, photosynthetic CO2 assimilating microalgae and cyanobacteria. The project was planned for two years of which the first year, described in this report, was funded by UOOR. Attempts made to isolate and cultivate photosynthetic, H2S utilizing, CO2 assimilating micro ‐ organisms were not successful, thus the research material of the project consisted of microalgae and cyanobacteria strains which were isolated from the close vicinities of geothermal power plants. These consisted of 31 species growing at different temperatures. Growth rate (g / L / day) was estimated for the strains as well as estimates of chlorophyll and carotenoids content. A method for estimates of fat content in microalgae ie the Nile Red method was tested on several microalgae and cyanobacteria species. Further development of this method is needed and planned for the next year of the project. Further attempts for isolation of photosynthetic, anoxygenic bacteria species is also planned for the next year of the project.

Report closed

View report

Reports

Properties of silver. Impact of location and season / Properties of dulse. Influence of location and season

Published:

06/06/2011

Authors:

Þóra Valsdóttir, Karl Gunnarsson

Supported by:

AVS

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Properties of silver. Impact of location and season / Properties of dulse. Influence of location and season

This report reports on the results of a study of silver collected from June to October 2010 at two different growth sites of silver, on cliffs and boulders (Bolaklettar) and on islands (Fossárvík). The aim was to obtain reliable information on the effect of location and time of year on the appearance, nutritional value, amount of trace elements and minerals in silver in these places. The effect of season and location was measured on most of the measures analyzed, both composition and properties. The degree of variability varies depending on the factor involved. In some cases it can be significant and therefore important to collect silver in the places and time of year that is most favorable.

Dulse was collected from June to October 2010 at two different locations, rocky shore and at sandbank were the sea was mixed with fresh water. The aim was to collect data on the influence of location and season on the appearance and chemical composition of dulse. Significant differences were found on several attributes. Knowledge of the variability in ie color and protein content assist processors in selecting the most favorable raw material for their product.

View report

Reports

Symposium on seaweed for food February 26th 2011. Summary

Published:

01/06/2011

Authors:

Þóra Valsdóttir, Karl Gunnarsson, Róbert A. Stefánsson, Rósa Jónsdóttir

Supported by:

AVS

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Symposium on seaweed for food February 26th 2011. Summary

An open seminar, Forðabúr fjörunnar, was held in Stykkishólmur in February 2011 with the aim of encouraging increased utilization of algae in Iceland, connecting the parties who have been working in this field and coming up with ideas for actions and projects that promote development. in algae processing. The seminar presented the results of recent research in the field of food algae, companies introduced themselves and encouraged discussions about opportunities and strategies in connection with the utilization of food algae off the coast of Iceland. Almost 50 participants attended the seminar and a variety of discussions ensued. The seminar included a proposal for the establishment of an interest group of parties working in the algae industry, which would, among other things, have the role of promoting the acquisition and dissemination of knowledge and experience to and between members.

Symposium on utilization of seaweed for food was held in Stykkishólmur February 26th 2011. The aim of the symposium was to encourage utilization of seaweed in Iceland, give stakeholders opportunity to meet and elicit ideas for actions and projects which can contribute to further development of the seaweed industry in Iceland. At the symposium results from recent research on seaweed and seaweed companies were presented. Opportunities and strategy for improved utilization and value of seaweed were discussed. The first step in establishing Icelandic seaweed consortium was taken.

View report

Reports

Effect of temperature control on the efficiency of modified atmosphere packaging of cod loins in bulk

Published:

01/06/2011

Authors:

Hélène L. Lauzon, Kolbrún Sveinsdóttir, Magnea G. Karlsdóttir, Eyjólfur Reynisson, Björn Margeirsson, Emilia Martinsdóttir

Supported by:

EU IP Chill ‐ on (contract FP6‐016333‐2)

Contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

Effect of temperature control on the efficiency of modified atmosphere packaging of cod loins in bulk

The aim of the experiment was to compare the freshness, quality and shelf life of sub-chilled (CBC) cod necks in air storage and in aerated packages (MAP) at controlled temperatures to simulate temperature fluctuations during transport and distribution in the European market. Changes in the composition of the gas in the packages were monitored and sensory assessments and microbial and chemical measurements were performed. The fish was caught in bottom trawls in the spring and processed three days after fishing. There was a two-day prolongation during the freshness period and one day for the shelf life of fish in aerated packages (2.7 kg in a tray) compared to air (3.1 kg) in foam plastic, despite a 0.5 ° C difference in the average temperature of the groups and the air group was stored at lower temperatures (‐0.3 ± 0.9 ° C). The greatest temperature fluctuations led to the greatest shortening of the freshness time in air-conditioned packages. Cod saddles stored subcooled at -1.1 ± 0.1 ° C had a shelf life of 13 days. The results of microbial counts and chemical measurements showed the importance of Photobacterium phosphoreum in the formation of TMA in the process of damaging cod necks during both air and air exchange packaging. MAP and subcooling slowed down and changed the damage process. MAP increased drip by 2% in the later stages of storage.

The aim of this study was to compare freshness, quality deterioration and shelf life of CBC (combined blast and contact) ‐treated cod loins packaged in bulk under different atmospheres (air or modified atmosphere, MA) and stored under different temperature profiles to mimic temperature changes during transport and distribution to European markets. Sensory, chemical, microbial and headspace gas composition analyzes were performed regularly. The fish was caught by trawler in the spring and processed 3 days post catch. Following simulation of current sea freight conditions and distribution to European markets, a 2 ‐ day and 1 ‐ day increase in freshness period and shelf life of MA ‐ packaged fish (2.7 kg in trays), respectively, was observed compared to air ‐ stored loins (3.1 kg in EPS boxes). This is despite a mean product temperature difference of 0.5 ° C between the products, being lower (‐0.3 ± 0.9 ° C) for air ‐ stored fish. Abusive conditions had the greatest impact on the reduction of the freshness period for MAP fish. Superchilled storage of MAP loins (‐1.1 ± 0.1 ° C) resulted in a 13 ‐ day shelf life. Evaluation of microbial and chemical indicators emphasized the importance of Photobacterium phosphoreum and TMA formation in the deterioration of cod loins stored in air or MA, while superchilled MAP storage delayed as well as modified the spoilage pattern. MAP increased drip loss by about 2% at late storage.

View report

Reports

Influence of drying methods on the properties of dulse

Published:

01/06/2011

Authors:

Þóra Valsdóttir, Irek Klonowski

Supported by:

AVS

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Influence of drying methods on the properties of dulse

Knowledge of the parameters that control the quality and properties of dried silver (Palmaria palmata) is relatively small and little is known. If the utilization of brokers is to be increased and expanded, it is important to study these variables in more detail and document them. This report presents the results of experiments whose main objective was to compare the effects of three different drying methods on the nutritional value and physical properties of dried silver. The drying methods compared were solar drying, oven drying and lyophilization, as well as the effect of the effect on the sun-dried salts was assessed. Comparable changes in nutrients were measured after the drying process. The main difference in terms of drying methods was detected in the amount of vitamin C. There was a noticeable difference in color and texture. Taste properties were not measured but it is believed that there is some difference. Despite the fact that the results gave certain answers, many questions arose when interpreting them. There is therefore a need to acquire more knowledge about the properties of silver and their interaction with different processing factors.

The influence of three different drying methods on selected nutritional and physiochemical properties of dulse were compared; sun drying, oven drying and freeze drying. Similar influence was found on nutritional components. The main difference was found on vitamin C retention. Difference was found as well in color and texture. Flavor characteristics were not analyzed, however some differences are expected. Despite giving some answers, the results raised many questions on their interpretation. There is a need for extended knowledge on the properties of dulse and their interplay with different processing parameters.

View report
EN