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Reports

Shelf life tests on cod pieces: Effects of supercooling on salt and protein injected cod muscles

Post author By admin
Post date 01/12/2007

Published:

01/12/2007

Authors:

María Guðjónsdóttir, Kolbrún Sveinsdóttir, Hannes Magnússon, Sigurjón Arason

Supported by:

Rannís Research Fund

Contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

Shelf life tests on cod pieces: Effects of supercooling on salt and protein injected cod muscles

An integrated refrigeration study was performed on the effects of salting, protein injection and subcooling on the quality, chemical and physical properties of salt and protein injected cod muscles. The study shows that by injecting salt and protein into the muscle, utilization can be improved, drip reduced and the boiling efficiency of the muscle increased. On the other hand, the injection of salt and protein into muscles increases microbial growth and the formation of erratic alkalis, thus shortening the shelf life of the product. However, lowering the storage temperature could inhibit the growth of microorganisms and the formation of erratic alkalis. Decreased storage temperature, however, led to cell damage due to ice formation on the surface regardless of the salinity of the muscle. Therefore, it is not considered desirable to store fresh or lightly salted cod muscle at temperatures below -2 ° C. The effect of rinsing the samples in a brine bath after injection was also investigated. Such rinsing did not significantly affect the water and salinity or efficiency of the samples, but showed a reduction in the formation of erratic bases. It is therefore advisable to rinse fillets in brine after injection to prevent damage to the best extent possible. Sensory evaluation results showed that the properties of the muscle changed significantly with the injection of salt and protein into the muscle, but the injected groups lost their freshness characteristics until the fresh untreated control group.

A combined cooling experiment was performed on the effect of salting, protein injection and superchilling on the quality and physicochemical properties of brine and protein injected cod muscle. The study showed that brine and protein injections lead to increased processing and cooking yield, as well as decreased drip. Injection of salt and proteins increase on the other hand microbiological growth and the formation of volatile nitrogen bases, which in turn leads to shorter shelf life. By lowering the storage temperature this growth of microorganisms and volatile nitrogen bases could be decreased. If the storage temperature is kept too low this on the other hand led to cell damages due to ice crystallization on the muscle surface, independent on the salt content of the muscle. It is therefore not recommended to store fresh and light salted cod at temperatures below -2 ° C. The study also viewed the effect of brining the muscle after brine and protein injection. This brining had no significant effect on the salt or water content of the muscle but decreased the amount of volatile bases. It is therefore recommended that cod muscle is always washed in brine after injection to keep damaging processes at a minimum. Sensory analysis showed a significant difference between the characteristics of brine and protein injected samples to unprocessed cod muscle. The injected groups also lost their freshness characteristics earlier than the unprocessed control group.

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Tags Shelf life, Microorganisms, NMR, Overcooling, Microorganisms, Protein, Proteins, Sensory analysis, Sensory Evaluation, Storage quality, Superchilling

Reports

Shelf life tests on cod pieces: Effects of supercooling, pickling and gas packaging on the physical and chemical properties of cod muscles

Post author By admin
Post date 01/12/2007

Published:

01/12/2007

Authors:

María Guðjónsdóttir, Hannes Magnússon, Sigurjón Arason, Guðrún Ólafsdóttir, Sigurður Bogason

Supported by:

AVS, Rannís Technology Development Fund, Rannís Research Fund

Contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Shelf life tests on cod pieces: Effects of supercooling, pickling and gas packaging on the physical and chemical properties of cod muscles

An integrated refrigeration study was carried out on the effect of salting, different packaging methods and salting methods as well as the effect of subcooling on the quality and shelf life of cod muscles. The results show that storage is a more desirable salting method than injection salting from a microbiological point of view and with regard to drip and boiling efficiency. However, if the salinity during storage becomes too high, the muscle will gel. In the experiment, it was not considered to improve the quality of the fish to inject proteins into the muscle in addition to the salt. Microbial growth and the amount of wandering alkali decrease with decreasing temperature, so it is desirable to keep the temperature as low as possible, without the fish freezing. At -4 ° C, the surface of the fish in all groups, regardless of salinity, was frozen and the ice crystal formation increased with storage time. This ice crystal formation took place much more slowly at -2 ° C and is therefore considered a desirable storage temperature for lightly salted cod muscles. Air-packed packaging (MAP) also proved to be a more desirable storage method than foam packaging, as microbial growth and increase in erratic base was slower in the MAP packaging, which led to longer shelf life.

A combined cooling experiment was performed upon the effect of salting, different packaging and salting methods as well as the effect of superchilling on the quality and shelf life of cod muscle. The results show that brining is a better salting method that brine injection in terms of bacterial growth as well as increased yield. On the other hand, if the salt concentration becomes too high, gelation of the muscle proteins begins. The study also showed that injection of proteins along with salt injection did not improve the quality of the muscle. Microflora and the formation of volatile nitrogen bases decreased with lowering temperatures. It is therefore preferred to store fish at as low temperatures as possible, without letting the muscle water freeze. At -4 ° C the water at the muscle surface was frozen in all groups, independent of salt content, and the ice crystallization increased with storage time. This crystallization was much slower at -2 ° C and therefore this temperature is recommended for storage of light salted cod muscle. Modified Atmosphere Packaging (MAP) turned out to be a better packaging method than Styrofoam packaging, since the increase in bacterial growth and volatile nitrogen bases was slower in the MAP. This also lead to increased shelf life.

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Tags Physical and chemical properties, Ventilated packaging, MAP, NMR, Overcooling, Physicochemical properties, Salting, Salting, Superchilling

Reports

Use of bioactive substances in halibut farming

Post author By admin
Post date 01/12/2007

Published:

01/12/2007

Authors:

Jónína Þ. Jóhannsdóttir, Heiðdís Smáradóttir, Jennifer Coe, Rut Hermannsdóttir (MS student), María Pétursdóttir, Rannveig Björnsdóttir

Supported by:

Líftækninet HA (2005-2007), KEA University Fund (2006)

Use of bioactive substances in halibut farming

The main goal of the project was to promote the increased performance of halibut in fire and use environmentally friendly methods. Bioactive substances were used that were easy to obtain, contributed to the increased value of seafood and also had some of the desired activity, ie. bactericidal / inhibitory, prebiotic or immunostimulatory activity. Experiments were made with various materials in the project, ie. chitosan derivatives as well as peptides derived from blue whiting, cod and saithe. The effect of treatment with the substances was assessed in terms of the growth and performance of larvae and forage animals as well as in terms of the composition of the bacterial flora and the stimulation of a non-specific immune response in larvae. The main results indicate that the most suitable method for introducing substances into larvae is to use feed animals (Artemia) and a method was developed in the project to treat them. The bioactive substances did not appear to have a bactericidal effect in the rearing environment of the feed animals, but did contribute to a change in the composition of the bacterial flora. Bioactive substances seemed to be used primarily as supplements as feed animals were plump and playful. The performance and quality of larvae in the breeding units of Fiskey hf. is very different and there is no obvious relationship between the performance of the peritoneal stage and the performance and quality of the larvae at the end of the initial feeding. The composition of bacterial flora was also found to be very different in peritoneal larvae and larval feeding larvae. Three separate experiments were carried out in the Fiskey juvenile farm where the larvae in the initial feeding were treated with bioactive substances. The main results showed that it is important to treat with the right concentration of substances and for a reasonably long time as too much concentration can have a negative effect on the growth and metamorphosis of larvae. Treatment with blue whiting peptides was thought to give promising results and have a beneficial effect on larval metastasis. Bioactive substances did not appear to have a decisive effect on the number of bacterial bacteria in the gastrointestinal tract of larvae, but treatment with blue whiting and cod peptides could potentially alter the composition of the flora. Studies on the non-specific immune response of halibut larvae revealed the presence of C3 and Lysozyme from the end of the peritoneal stage, but IgM production does not begin until about 28 days after the start of feeding. Higher levels of IgM were detected during the first weeks in larvae treated with saithe peptides and this may indicate an immunostimulatory effect. The results of the project as a whole indicate that the bioactive substances studied did not have a decisive effect on the bacterial flora of the farm, but the treatment of larvae in starter feeding with the right concentration of bioactive substances could have a good effect on larval performance and stimulate larval immune response. of the farm when they have not yet developed a specialized immune response.

The aim of this project was to promote increased survival of halibut larvae during first feeding by using bioactive products. The bioactive products were selected by the criterion that they were easily accessible and induced any of the desired effects ie inhibiting bacterial growth, prebiotic effects or immunostimulants. The products studied are chitosan and peptide hydrolysates from blue whiting, cod and saithe. The effects of treatment were evaluated with respect to growth and survival of larvae and the live feed (Artemia) as well as effects on bacterial numbers or the community structure of the intestinal microbiota of larvae and stimulation of the innate immune system of the larvae. The results indicate that treating live feed (Artemia) is a suitable method to carry the bioactive products to the larval intestines during first feeding and a new technique has been standardized for treatment of the live feed with the products. The bioactive products did not affect the total bacterial count in the Artemia but the composition of the bacterial community may be changed as a result of the treatment. The Artemia seems to use the bioactive products as a food supplement and was well suited to be used as live feed. A significant variation in overall success of larvae was observed without any obvious correlation between survival of larvae at the end of the yolk sac stage and at the end of first feeding. A different bacterial pattern was observed in the intestine at the yolk sac stage compared to first feeding larvae. Three separate experiments were carried out in the halibut production units at Fiskey Ltd. where larvae were treated with various bioactive products. The results emphasize the importance of treating larvae with the appropriate concentrations of the products, as elevated concentrations can negatively affect growth and metamorphosis of the larvae. Treatment with peptides from blue whiting resulted in relatively good survival of larvae with similar success of metamorphosis compared to control units. The bioactive products did not affect bacterial growth but there were indications that peptides from blue whiting and cod may affect the composition of the intestinal community of bacteria in the larvae. Results from studies of the immunological parameters indicate the presence of C3 and Lysozyme already from the end of the yolk sac stage and the initialization of IgM production after approximately 28 days in feeding. Production of IgM was stimulated in larvae treated with peptides from saithe, indicating immunostimulating effects of this product. The overall results indicate that the bioactive products studied did not affect the bacterial flora during the first production stages of halibut larvae. However, if used in the appropriate quantities and at the right time, the products may promote survival and growth and stimulate the innate immunity of larvae.

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Tags Performance, Bacteria, Bacterial flora, Bioactive compounds, First stage of rearing, Immunostimulation, Bioactive substances, Halibut farming, Marine aquaculture, Molecular methods (PCR-DGGE), Immune stimulation, Production of larvae, Molecular Methods (PCR-DGGE), Survival

Reports

Prevention in aquaculture. Part A - Prevention in cod farming

Post author By admin
Post date 01/12/2007

Published:

01/12/2007

Authors:

Hélène L. Lauzon, Sigríður Guðmundsdóttir, Agnar Steinarsson, Matthías Oddgeirsson, Bergljót Magnadóttir, Ívar Örn Ásgeirsson, Berglind Gísladóttir, Eyjólfur Reynisson, Sólveig K. Pétursdóttir, Þuríður Ragnarsdóttir, Maja Herold Pedersen, Birgitte B. Budde, Bjarnheiður K. Guðmundsdóttir

Supported by:

AVS Fund (R 41-04)

Prevention in aquaculture. Part A - Prevention in cod farming

The aim of Part A was to increase the efficiency of cod farming by increasing the survival of eggs / larvae and promoting increased growth of larvae in starter feeding. The results show that the composition of the microbial flora explained the declines better than the total microbial or Vibrio counts. Extensive analysis of the microflora of aquaculture systems and larval stage results led to the determination of desirable and undesirable bacteria. Chemical measurements in cod farming at the roe and larval stages showed that little accumulation of substances took place in the farmed liquid, except at the beginning of dry feeding. The choice of additive bacteria was decided on the basis of a specific screening process and expected use in cod farming. The use of supplemental bacteria in bathing eggs and / or larvae was examined, but continuous bathing from the egg stage onwards to the larval stage usually led to better results, greater growth and vitality. The use of complementary bacteria also affected the microflora and the development of larvae shortly after hatching, which was confirmed, among other things, by measurements of proteins from the immune system. The use of supplemental bacteria in juvenile farming was investigated and indicated an increase in growth rate. It has not been possible to prove that increased disease tolerance can be achieved with the use of supplementary bacteria in juvenile farming, but there were positive indications of this. The main bottlenecks in the development of prevention methods were the live food animals, which caused a high microbial load. The development of probiotic rodents with other complementary microorganisms did not work well. Investigations into the infectious potential of the cod bacteria in cod fry showed that they did not cause any symptoms or cause death.

The aim was to increase the competitiveness and success of cod aquaculture by increasing survival and development from hatching through the larval stage. This was achieved by developing preventive methods to control important chemical and biological parameters. The results revealed that differences in microbiota composition between different larval treatments explained the success or lack thereof, better observed than total microbial or Vibrio counts of rearing water or larvae. Microbiota analysis and survival rates have hence led to the definition of desirable and undesirable bacteria, the latter being especially Vibrio sp. Assessment of selected chemical parameters was performed at pre- and posthatching periods, indicating NH3 build-up in the rearing water upon dry feeding. The selection of probiotic bacteria was based on a specific screening and their anticipated use in cod farming. Application of selected bacteria was tested for surface treatment of eggs and / or larval bathing, and the continuous use before and after hatching usually led to increased survival, growth and tolerance as well as influencing larval microbiota and immunological development. Application of selected probiotic bacteria was also tested with cod juveniles with increased growth rate. Disease resistance of probiotic-fed juveniles to fish pathogens was not confirmed. Development of probiotic rotifers proved difficult due to their high microbial load. Probiotic strains applied ip to cod juveniles were not found to be virulent

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Tags Additive bacteria, Chemical load, Aquaculture code, Chemical load, First developmental stages, Prevention, First stage of rearing, Microbiota, Microbial flora, Preventive measures, Probiotic bacteria, Cod farming

News

Photos from the signing of the agreement between Matís and UI

Post author By admin
Post date 29/11/2007

Matís and the University of Iceland recently signed an agreement to work closely to strengthen research and education in food science, food engineering, biotechnology and food safety. The agreement also aims to significantly increase the number of undergraduate and graduate students in these subjects at the University of Iceland.

KEY POINTS OF THE UNIVERSITY OF ICELAND AND MATÍS AGREEMENT:

To increase research in food science, food engineering, biotechnology and food safety.
To strengthen the theoretical and practical education of university students in food science and related disciplines.
That the University of Iceland is a leader in selected fields of expertise and attracts students and scholars on an international level.
That the University of Iceland and Matís use the possibilities for joint operation of equipment for the benefit of joint projects.
To increase the number of students in undergraduate and graduate studies in food science and related subjects for the benefit of the general public and companies.
That the University of Iceland be at the forefront of innovation in these fields of study.

News

Matís and SINTEF: Increased international cooperation: Strengthens research and development in the food industry in Iceland

Post author By admin
Post date 29/11/2007

Matís (Matvælarannsóknir Íslands) and the Norwegian research company SINTEF have entered into an agreement with the aim of promoting research, development and value in the fisheries and food industry in Iceland and Norway. The agreement enables Matís to participate in research projects in collaboration with SINTEF and Norwegian companies in aquaculture and food research. The agreement will also increase Matís' ability to promote its activities abroad and participate in more international and pan-European research projects.

Close collaboration with the University of Technology in Trondheim

The agreement will also make it possible for Icelandic companies and institutions to develop collaboration with SINTEF and companies and research institutes abroad.

SINTEF's main strengths for the Icelandic fisheries and food industry are knowledge in the fisheries sector, such as aquaculture. SINTEF can offer assistance in research and development of cod farming and processing technology in the fisheries sector, including fishing. SINTEF works closely with NTNU (Trondheim University of Technology), which increases the potential of Icelandic educational institutions for international collaboration.

In the same way, Matís can contribute expertise to companies in Norway in processing technology in the fisheries sector, aquaculture and biotechnology research for the fisheries sector.

Contributes to increased knowledge in the Icelandic food industry

"Matís' vision for the future is to strengthen the competitiveness of the Icelandic food industry. We believe that with our agreement with SINTEF, Matís has taken an important step in that direction. SINTEF is a respected knowledge and research company on an international level, which has very valuable knowledge of the challenges facing Icelanders, such as aquaculture and processing technology in the fisheries sector. SINTEF can therefore contribute to increased knowledge in the Icelandic food industry and strengthen the potential of Icelandic companies and universities abroad. The collaboration also opens up new possibilities in research projects on behalf of the European Union. We therefore expect a lot from our collaboration with SINTEF in the coming years and we hope that it will further increase the value in the Icelandic food industry, "says Sjöfn Sigurgísladóttir, CEO of Matís.

About SINTEF: Independent institute for research and development at the University of Technology in Trondheim, Norway. It operates in fisheries and aquaculture, among other places. Also in construction, civil engineering, information technology, chemistry, oil industry and energy industry.

The main objectives of the agreement between Matís and SINTEF

Work on joint research projects with companies in Iceland and Norway.
Collaborate on consolidating funding for research projects, not least in large European projects.
Mutual presentation of partner companies and research projects.

News

New employee in Ísafjörður

Post author By admin
Post date 27/11/2007

Cecilia Elizabeth Garate Ojeda has taken on the job of specialist at Matís in Ísafjörður. Ceclia, from Peru, graduated with a BCs in Industrial Engineering from the Universidad Nacional de San Agustin Arequipa in Peru in 2000 and an MBA from the Industrial Business School in Madrid, Spain in 2006.

With the introduction of Cecila, there are now four full-time positions at Matís in Ísafjörður.

News

Extensive research and increased education in food science: Aiming to increase the number of students

Post author By admin
Post date 23/11/2007

The University of Iceland and Matís (Matvælarannsóknir Íslands) have decided to work closely to strengthen research and education in food science, food engineering, biotechnology and food safety. The aim is to significantly increase the number of undergraduate and graduate students in these subjects at the University of Iceland in accordance with a co-operation agreement signed by the University of Iceland and Matís.

The role of the University of Iceland consists of research in the field of study within the relevant faculties of the university and guidance of students in master's and doctoral studies, in addition to being responsible for teaching in the relevant disciplines. Matís' role is to be professionally responsible for selected disciplines as well as to ensure facilities for practical learning, teaching and research. Matís will also direct the practical teaching and training of students in BS studies in food science, which aims, among other things, to increase the number of students graduating in the field of study.

The aim of the agreement is, among other things, to strengthen the competitiveness of Icelandic products and the economy, to improve public health and to ensure food security and sustainable utilization of the environment through research, innovation and services.

"Matís is a leading research institute in the fields of food science, food engineering, biotechnology and food safety. Matís has for years been one of the most important partners of the University of Iceland. The university intends to strengthen research and teaching in these areas in the Science Parks, which will be built on the campus in the near future. This agreement is an important part of the University's intention to strengthen formal collaboration with Matís in the field of engineering and science and in the field of health sciences, not least in nutrition and public health. The University of Iceland has set itself ambitious goals for success in research in the coming years, but close collaboration with powerful research institutes such as Matís is an important milestone in that journey, "says Kristín Ingólfsdóttir, Rector of the University of Iceland.

"The agreement with the University of Iceland offers new and exciting possibilities for Matís and we are convinced that it will further strengthen research work in food science and attract more students to such disciplines within the walls of the university. Matís' role is to strengthen the competitiveness of Icelandic products and the economy, improve public health, ensure food security and the sustainable use of the environment. In order for the company to achieve its set goals, it is important that it works closely with the University of Iceland, which is the largest educational institution in the country, "says Sjöfn Sigurgísladóttir, CEO of Matís.

News

Even more from the Matís conference

Post author By admin
Post date 20/11/2007

More than 160 people filled the Gullteig hall at the Grand Hotel on Thursday, when the Matís conference, Food and the Future, was held, for the first time. In the hall outside the conference, it was possible to get to know food design and innovation in the food industry, such as mountain confectionery, thyme drinks and farmed fish. Furthermore, guests were given the opportunity to taste dried fish from Gullfisk.

Great interest in the conference now is an incentive for the company to continue next year with a similar conference and exhibition and do even better then.