Author: admin

Reports

Microbial diversity in the Icelandic fishing grounds

Published:

01/12/2011

Authors:

Eyjólfur Reynisson, Sveinn Haukur Magnússon, Árni Rafn Rúnarsson, Kristinn Guðmundsson, Erla Björk Örnólfsdóttir, Viggó Þór Marteinsson

Supported by:

Fisheries Project Fund

Contact

Viggó Marteinsson

Research Group Leader

viggo@matis.is

Microbial diversity in the Icelandic fishing grounds

The diversity of microorganisms in the ocean around Iceland is largely unknown, but little or no research has been done to date. In this study, samples of the sea around the country were collected for analysis of microbial concentrations by flow cytometry and their diversity using molecular biological methods. A total of 504 sea samples were collected; 483 samples from the MRI's spring rally, 16 samples from Breiðfjörður and 5 samples were collected north of the Westfjords with specially equipped bottom trawling equipment. From the spring rally, selected samples were further investigated, they came from Selvogsbanki, Siglunes and Langanes as well as each sample west of Látrabjarg and Hornbanki. The microbial concentration was highest in Selvogsbanki, where the total count was about 1.6 million cells / mL of seawater. However, the calculated mean of all samples was 0.68 million cells / mL. The species composition of the microflora was determined by amplification and sequencing of the 16S bacterial gene. A total of 528 sequences were sequenced showing 174 different 16S bacterial sequences in the samples and 52% were found to belong to previously unknown bacterial species. The diversity of the microbial flora was generally high, with the exception of trawl tails. Eight batches of bacteria were detected in the samples to varying degrees. Cyanobacteria and Cyanobacteria-like sequences were predominant in all samples except for the 353-0m sample at Selvogsbanki, where their proportion was only 4%. Alpha and Gamma ‐ protebacteria predominated there. Of the other groups, Flavobacteria was regularly diagnosed together with other groups in a smaller proportion. Differences in the microbial composition of marine samples were assessed using a key factor analysis of the fingerprints of microbial communities obtained using t-RFLP technology. Overall, the main difference was in samples from each sample cycle, ie. from vorralli, Breiðafjörður and the tail of a trawler. The variability within the samples from the spring rally went hand in hand with the sampling point where samples from Selvogsbanki showed greater mutual similarity compared to the samples north of Siglufjörður and west of Iceland which were more different from each other. Data from the fingerprints of microbial communities in different samples showed a correlation between certain variables in the fingerprints of the communities with environmental factors that were measured during the sampling. Temperature had the most to say but also fluorescence and salinity. Vibrio was screened. Paramaemolyticus in warm seawater samples from the south of the country where the sea surface temperature was between 8-10 ° C. No V. parahaemolyticus was detected in these samples. The results of this project can be regarded as an important basis for further research on microorganisms in Icelandic waters. Ongoing research in this field can be of great significance in the long term to assess the impact of foreseeable environmental changes due to global warming on marine life and fish stocks in Icelandic waters. 

The diversity of microorganisms in the ocean around Iceland is largely unknown and little or no research has been conducted to date. In this study, seawater samples around the country were gathered for analysis concentration and diversity of microorganisms using flow ‐ cytometry and molecular methods. A total of 504 samples were collected. All samples were analyzed with regards to microbial counts while samples from selected areas were investigated further, from Selvogsbanki, Siglunes and Langanes. Microbial concentrations were highest at Selvogsbanki, where the total counts were around 1.6 million cells / ml. Arithmetic mean of all samples was o.68 million cells / ml. Species composition of microbial flora was determined by amplification and sequencing of the 16S bacterial gene. A total of 528 16S sequences were sequenced, and showed 174 different bacterial sequences. 52% of the sequences belonged to previously unknown bacterial species. Eight divisions of bacteria were detected in the samples. Cyanobacteria and cyanobacteria ‐ like sequences were predominant in all samples except sample 353‐0m in Selvogsbanki where the ratio was only 4% and alpha and gamma‐ proteobacteria were predominant. Of other ranks identified, Flavobacterium were regularly detected along with other less frequent groups. The difference in microbial composition in the sea samples was assessed by principal component analysis of the microbial community fingerprint obtained by t ‐ RFLP technique. Variability within the samples was dependent upon sampling point, samples from Selvogsabanki showed more correlation with other samples from that area - than with samples from Siglunes or the west coast of Iceland that showed more intrinsic diversity. The community fingerprint and changes in the fingerprint shows correlation to changes in environmental factors measured at sampling. Temperature was the most important environmental factor, along with fluorescence and salinity. Samples from the warmer waters off the south coast were screened for Vibrio parahaemolyticus, but none was detected. The results of this project can be seen as an important basis for further studies of microorganisms in Icelandic waters. Continued research in this area can be of great importance for the evaluation environmental change and the effects of global warming on the marine environment and exploitable marine species in Icelandic waters.  

View report

Reports

UV ‐ light surface disinfection / Disinfection of surfaces with UV light

Published:

01/12/2011

Authors:

Árni R. Rúnarsson, Eyjólfur Reynisson, Sveinn H. Magnússon, Kristinn Andersen, Viggó Marteinsson

Supported by:

Technology Development Fund

Contact

Viggó Marteinsson

Research Group Leader

viggo@matis.is

UV ‐ light surface disinfection / Disinfection of surfaces with UV light

The effect of UV radiation on disinfection is well known. UV radiation is lethal to microorganisms, especially UV-C radiation with wavelengths around 260nm (short wave). Radiation at that wavelength causes damage to the structure of the genetic material and prevents DNA transcription or microbial growth. Although the effects of UV light for disinfection are well known, its use for disinfection in food processing is relatively new. This report describes the tests for the antimicrobial effect of UV lamps on the microbial content of the meat processing line. The results of the tests show that UV light causes a statistically significant decrease in the number of microorganisms on the conveyor belt of the production line. Installation of UV lamps over conveyor belts will therefore be able to reduce microbial contamination from conveyors and processing surfaces to raw materials.

The effects of UV ‐ radiation for disinfection are well known. UV radiation is lethal to microorganisms, especially UV ‐ C radiation with wavelengths around 260nm (short wave). Short wave UV irradiation causes damage to the structure of DNA and prevents DNA transcription, thereby preventing microbial growth. Although the effects of UV light for disinfection are well known, its use for disinfection in the food processing environment is relatively new. This report describes the testing of the inhibitory effects of UV lamps on microbial growth on conveyor surfaces in meat processing. Test results show that UV light causes a statistically significant reduction in microbial load on the conveyor belt. Installation of UV lamps over conveyors in meat processing can therefore be expected to reduce the transfer of microbial contamination from conveyor belts and processing surfaces onto the raw material.

View report

Reports

Germicidal effects of UV light on processing line surfaces and pork shelf life / Effect of UV light on microbial contamination of processing surfaces and shelf life of pork products

Published:

01/12/2011

Authors:

Sveinn Magnússon, Eyjólfur Reynisson, Viggó Marteinsson

Supported by:

Technology Development Fund

Contact

Viggó Marteinsson

Research Group Leader

viggo@matis.is

Germicidal effects of UV light on processing line surfaces and pork shelf life / Effect of UV light on microbial contamination of processing surfaces and shelf life of pork products

The antimicrobial effect of UV radiation has been known for a long time, but UV radiation at 254nm (UV ‐ C) causes damage to the genetic material of cells and prevents microbial growth. The use of UV lighting for disinfection has increased, for example in the food industry - where UV radiation can be used to disinfect processing surfaces and food - thereby increasing safety and extending the shelf life of food. This report describes a test of the effect of UV exposure on the processing surface on the shelf life of meat products. The effect of UV exposure on the surface of meat processing - the conveyor belt and cutting board - on the shelf life of pork products was examined. The results of the study show that UV exposure has the effect of reducing the microbial content of processing surfaces. The results regarding the effect on shelf life were not decisive, but indicate that with a clean processing line and UV lighting on the processing surface, the shelf life of pork products from the processing line can be increased.

UV radiation at 254nm (UV ‐ C) causes damage to the genetic material of cells and prevents microbial growth. The use of UV light for disinfection is increasing eg in the food production industry - where UV radiation can be used for disinfection of food production surfaces and foods - and thereby increase food safety and extend product shelf life. This report describes the testing of the effects of UV lighting on surfaces in food processing facility on product shelf life. Effects of UV lighting on process line surfaces - conveyor belt and cutting boards - on the shelf life of pork was examined. The results of the study show that UV reduces the bacterial load on process line surfaces. Regarding the effects on pork shelf life the results were not significant but suggest that cleaner process lines and UV lighting on process line surfaces can increase the shelf life of pork products.

Report closed until 01.01.2014 / Report closed until 01.01.2014

View report

Reports

Microbial flora in Icelandic groundwater

Published:

01/12/2011

Authors:

Sveinn Magnússon, Eyjólfur Reynisson, Árni Rúnarsson, Viggó Marteinsson

Supported by:

Research Fund

Contact

Viggó Marteinsson

Research Group Leader

viggo@matis.is

Microbial flora in Icelandic groundwater

In the project "Icelandic Water Resources", considerable costs were spent on obtaining groundwater samples in many parts of the country and also on analyzes of various physical and chemical properties of the samples. The biological characteristics of the water were not considered, but this possibility was kept open for some of the samples by using microbial filters for storage at -20 ° C. In the project "microbial flora in Icelandic groundwater", the aim was to examine whether it would be possible to use the filters that had been stored frozen for several years to map microbial flora in Icelandic groundwater. Of the 59 filters that had been stored at 2020 ° C and tested, 19 were detected by t ‐ RFLP analysis, still only 5 by 16S rRNA clone analysis. For most of the samples, PCR amplification of the species identification gene could not be obtained. These low yields indicate that the DNA of the microorganisms on the filters has not been well preserved and has broken down during long-term storage. It is also possible that the number of microorganisms was low and thus little DNA was present. However, it cannot be ruled out that the samples could be used to map the microbial diversity of the more groundwater samples if more extensive tests are performed, such as changes in PCR conditions and the use of other DNA polymerase enzymes. The samples that could be cloned and used to sequence 16S rRNA genes were taken in the range of 3-83 ° C. The results showed that the samples largely consist of common environmental bacteria that are common in environments such as water, soil and vegetation. There was a great variety between samples and a lot of microorganisms that are still uncultivable.

Within the project “Vatnsauðlindir Íslands” considerable efforts and cost was spent to collect and analyze various physical and chemical properties of groundwater samples from around the country. Biological characteristics were not analyzed within the project but filtered microbial samples were kept and preserved at ‐20 ° C for potential future analyzes. In this project “Örveruflóra í íslenska grunnvatni”, the aim was to analyze the preserved filters and see if they could be used for mapping the microbiological flora in Icelandic groundwater. OF the 59 filters analyzed, 19 could be analyzed with t ‐ RFLP and only 5 with 16S cloning. The great majority of the samples did therefore not give any PCR amplification for the 16S gene. These low recoveries indicate that the DNA of the microorganisms on the filters has degraded during the long term storage. It is also possible that the number of bacteria on the filters was low and therefore limited DNA present. It can however not be overlooked that the samples could be used for mapping microbial groundwater diversity with more extensive testing of PCR conditions and different DNA polymerase enzymes. The samples that could be cloned and sequenced where sampled from water of temperatures varying from 3‐83 ° C. The results showed that the samples consist largely of environmental bacteria common in eg soils, water and vegetation. A great diversity was observed between the samples and numerous microorganisms that are still uncultivable.

Report closed until 01.01.2014

View report

Reports

Microbial density in Icelandic waters

Published:

01/12/2011

Authors:

Eyjólfur Reynisson, Sveinn Haukur Magnússon, Viggó Þór Marteinsson

Supported by:

Fisheries Project Fund

Contact

Viggó Marteinsson

Research Group Leader

viggo@matis.is

Microbial density in Icelandic waters

The diversity of microorganisms in the ocean around Iceland is largely unknown, but little or no research has been done to date. This report describes the first comparative results from a study on the microbial diversity of the ocean around the country. Sea samples around the country were collected in the spring of 2010 and 2011. The density of microorganisms in these samples has now been examined by microbial flow analysis and comparisons made by depth, location and between years. The results show that the diversity varies from region to region. The sea to the south of the country generally shows 40-60% more microbial density than the sea to the north of the country. Variability is also seen in the growth of algae or algae flowers. The results are the basis for further research into the microbial composition and diversity of the ocean around the country - which is already underway within the project.

The diversity of microorganisms in the ocean around Iceland is largely unknown and little or no research has been conducted to date. This report describes the first comparative results of microbial diversity in the sea around the country. Sea ‐ samples around the country were collected in the spring of 2010 and 2011. The density of microorganisms in these samples was studied by flow cytometry and comparisons made by the depth, location and year. The results show that diversity varies by region. The sea south of the country has approximately 40‐60% higher microbial density than the sea north of the country. Variation is also seen in relation to the growth of algae or algal blooms. These results are the basis for further research on the microbial composition and diversity of the sea around the country - already underway within project. 

Report closed until 01.01.2014 / Report closed until 01.01.2014

View report

Reports

Attitudes and fish consumption in Iceland 2011

Published:

01/12/2011

Authors:

Kolbrún Sveinsdóttir, Dagný Yrsa Eyþórsdóttir, Gunnþórunn Einarsdóttir, Emilia Martinsdóttir

Supported by:

Student Innovation Fund, Rannís

Contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

Attitudes and fish consumption in Iceland 2011

The aim of the study was to examine consumption habits and attitudes related to seafood among Icelanders aged 18-80. A survey was set up online and letters were sent to a sample from Statistics Iceland in June 2011 and responses were received from 525 people. The aim was also to examine the changes that have taken place in Icelanders' attitudes and fish consumption since the last figures were published in 2006 for people aged 18-26. Attitudes and consumption of Icelanders were analyzed by gender, age, place of residence, education, monthly household income before tax, number in the household and number of children under 18 in the household. On average, Icelanders eat fish as a main course about twice a week. Haddock is the most popular species on the tables of the people and is consumed about once a week, followed by cod. On average, Icelanders take fish oil about four times a week, but in total about half of Icelanders take fish oil daily and 62% three times a week or more. In general, Icelanders seem to eat fresh but frozen fish more often and very little is bought from prepared fish dishes chilled or frozen. Attitudes towards eating fish are generally very positive and the vast majority consider fish healthy and good. Most people believe that family has the most encouraging effect on fish consumption and that a wider budget, easier access to fresh fish and a wider range of fish could have an effect on increased fish consumption. There is a big difference between fish consumption and the attitudes of men and women. Women prefer to buy food and place more emphasis on hygiene, freshness, accessibility and price. They are also of the opinion that it is expensive to eat fish. There was a significant difference between age groups, both in terms of total fish consumption frequency, consumption of different fish products and attitudes. Fish consumption increases with age, as does fish oil consumption. The emphasis on hygiene is lower among younger people. There was a difference in the consumption behavior and consumption of different fish species and products according to residence, which can probably be largely explained by traditions and different supply of fish. Most people, especially those in the older age group, find it rather expensive to eat fish. On the other hand, they find fish more valuable than younger ones. However, it seems that the youngest group is even willing to pay more for fish, as they are of the opinion that a wider range of ready-made fish dishes and fish dishes in restaurants could have an effect on increased fish consumption. Positive changes have taken place in fish consumption and attitudes of people aged 18-26 in the last five years. This group is now more in favor of fish and the frequency of fish consumption has increased somewhat, which is mainly explained by increased fish consumption outside the home. Consumption of fish oil and diversity in the choice of seafood seems to have increased. In this age group, there has been an increase in the consumption of fresh fish, sushi, salted fish and chilled semi-prepared dishes.

The aim of the study was to investigate seafood consumption and attitudes among 18‐80 year old Icelanders. A total of 525 people completed a web-based survey. The aim was also to study changes in attitudes and fish consumption in the last five years among people 18-26 years. The data were analyzed by gender, age, residence, education, income, number of household members and number of children below 18 years. On average, the fish consumption frequency (fish as main course) is around two times a week. Haddock is the most frequently consumed fish species and is consumed around one time per week. Fish oil is consumed four times a week on average, but 50% of the participants consume fish oil every day. Fresh fish is more frequently consumed than frozen fish and ready fish meals, chilled or frozen, are rarely bought. Attitudes towards consuming fish are generally very positive. Most people consider family to have the most encouraging influence on their fish consumption and that less stringent finances, easier access to fresh fish and more variety of fish could positively influence their fish consumption. Fish consumption pattern and attitudes differ by gender. Women more frequently purchase food and emphasize more healthy food, freshness, access and price. Large differences were found between different age groups, both regarding fish consumption frequency, fish products and attitudes. Fish consumption and fish oil consumption frequency increase with age. Emphasis on healthy food are less among younger people. Consumption habits and consumption of different fish species and products differ by residence around the country. This can largely be explained by different traditions and different fish supply. Most people, especially in older age groups consider it expensive to consume fish. They are, however, more likely to consider fish money worth compared to younger people. The youngest age group appears though to be ready to pay more for fish as their opinion is that more variety of ready fish meals and fish courses at restaurants could positively influence their fish consumption. The last five years, positive changes in fish consumption and attitudes among people 18-26 years have occurred. This group now consumes fish more frequently, the varity in their choice of seafood has increased. The consumption of fresh fish, sushi, salted cod and chilled oven ready fish meals has increased among this group.

View report

Reports

Procedures on board lumpfish vessels

Published:

01/12/2011

Authors:

Gunnar Þórðarson, Óskar Torfason

Supported by:

Westfjords Growth Agreement

Contact

Gunnar Þórðarson

Regional Manager

gunnar.thordarson@matis.is

Procedures on board lumpfish vessels

The main purpose of the project "Grasshopper, value from underutilized raw materials" is to create employment in the Westfjords following the decision of the Minister of Fisheries to oblige grayling fishermen to bring all catch, including gutted grayling, ashore from the year 2012. In connection with the project It was decided to conduct a survey of how the West Fjords grayling fleet was prepared to deal with new demands, and what the shipowners' attitudes were to changes in the working environment. Shipowners were interviewed in Stöndur, by Djúp and in the south of the Westfjords. The interviews were based on a questionnaire which, among other things, sought information about current equipment, what changes had followed new rules and their attitudes towards change. Special emphasis was placed on attitudes towards gutting at sea or on land and the shipowners' ideas about prices for the grayling after roe collection.

The main purpose of the project "Lumpfish, the value of underutilized species" is to create jobs in the Westfjords following the decision of the minister of fisheries that lumpfish fishermen must bring the whole catch, including head/skin and fillets of lumpfish ashore, on and after coming fishing season of 2012. In connection with the project it was decided to carry out a survey of capability of the lumpfish fleet of Westfjords to meet the new requirements, and to seek ship owner's attitude to inevitable changes due to new regulation. A list of questions was used for the survey to underline the current situation in the fishing fleet and fishing captains attitude to further steps to be taken in a changed environment. Special emphasis was on their attitude to gutting lumpfish on board the boats or at factories ashore, and their idea of price for the lumpfish after collecting the roes. 

View report

Reports

Gæðakræklingur er gulls ígildi / Icelandic blue mussels - A valuable high quality product

Published:

01/12/2011

Authors:

Natasa Desnica, Sophie Jensen, Guðrún G. Þórarinsdóttir, Jón Óskar Jónsson, Hörður G. Kristinsson, Helga Gunnlaugsdóttir

Supported by:

AVS

Contact

Natasa Desnica

Research Group Leader

natasa@matis.is

Gæðakræklingur er gulls ígildi / Icelandic blue mussels - A valuable high quality product

In order for Icelandic mussel farming to grow and prosper, it is important to carry out basic research into the safety and quality of fresh Icelandic mussels that can be used by producers in marketing and selling the products. The purpose of this eighteen-month research project was to collect information on the safety and quality of mussels (Mytilus edulis) in market size (> 45 mm) grown off the coast of Iceland. A total of thirteen market-sized mussel samples were collected at four different breeding sites inland (Hvalfjörður, Breiðafjörður, Álftafjörður and Eyjafjörður) at different times of the year. Market-sized mussels were not found in Eskifjörður and this breeding site was therefore excluded from the project. Instead, samples were taken more often at the other four breeding sites than originally planned. Mussels were collected from breeding lines and time and location recorded. Weight, height and body mass were measured. The mussel was sexed and the stage of puberty was estimated in each sample. In this project, significant information was collected on nutrient content (protein, water, fat, ash) as well as bioactive substances such as selenium, zinc, carotenoids and fatty acid compositions in mussels from different cultivation sites and at different seasons. Unwanted inorganic trace elements (lead, mercury, cadmium, copper, nickel, arsenic, chromium and silver) were also measured in all samples. Work was also done on setting up and testing rapid measurement methods for measuring three types of algae toxins, ie ASP, PSP and DSP. The measurement methods were optimized against the equipment available at Matís and also measured reference samples (ie mussels with a known amount of algae toxin) to assess the quality of the measurements. Two types of rapid tests available on the market were tested to assess their performance in algae toxicity measurements in mussels. On the one hand, so-called Jellet tests were tested and on the other hand ELISA tests. The result is that both tests are relatively simple to use, however, it is necessary to test them on slightly more samples than was done here, in order to make a better assessment of how best to use them in quality control of mussel farming. It is necessary to be aware of the limitations of these rapid tests as they will not completely replace measurements by approved research methods. These tests, on the other hand, could significantly reduce the number of samples sent for approved measurements, as no samples would be sent when the pre-tests show that algae toxins are present and no mussels were allowed to be harvested. The results indicate that Icelandic mussels have an optimal nutrient composition, which is subject to natural seasonal changes. Multivariate analysis (PCA) shows that mussels contain a higher percentage of fat and protein in the spring (May and June), probably because the mussel is preparing to spawn at this time of year. In early autumn, the protein content decreases while the amount of unknown substances increases. At this time of year, spawning is complete, if not complete. The analysis also shows a weak positive correlation between protein and fat, but a strong negative correlation between protein and unknown substances. The concentration of heavy metals (mercury, lead, cadmium) was generally low, but in some cases the concentration of cadmium was higher than permitted by Icelandic and European Union regulations (1 mg / kg). It is therefore important to monitor the concentration of cadmium in Icelandic mussels before they go on the market. The results of fatty acid analysis show that Icelandic mussels contain significant amounts of the omega-3 fatty acids EPA (C20: 5n3) and DHA (C22: 6n3) as well as Palmitoleate (C16: 1n7), all of which are known for their beneficial effects on health. The results of the project show that Icelandic mussels are competitive in terms of nutrient composition and also contain positive bioactive substances. These results will undoubtedly be useful to mussel farmers in marketing presentations and planning regarding the harvesting and sale of mussel products.

In order to enable the Icelandic blue mussel industry to grow, market and sell their product, there is a critical need to perform some fundamental studies. The purpose of this eighteen months long research project was to investigate the quality and value of Icelandic blue mussels (Mytilus edulis) grown at different growing sites of Iceland. A total of 13 samples were collected from blue mussel culture sites around Iceland (Hvalfjörður, Breiðifjörður, Álftafjörður and Eyjafjörður). The Eskifjördur sampling site was excluded from the project due to the lack of market sized blue mussels and resulted in sampling from growing lines of four different culture sites. The mussels were characterized according to location, time of year, weight, length, meat yield and reproductive status. This report summarizes the considerable amounts of data obtained regarding the chemical composition of Icelandic blue mussels, including trace metals (lead, cadmium, copper, zinc, mercury, arsenic, selenium, chrome, nickel and silver), nutrients (moisture, protein, lipid and ash content) and bioactive components (carotenoids and fatty acid profile). In addition, the presence of common algal toxins in blue mussels was investigated and concluded that further work will be needed to optimize the rapid assays tested for measuring algal toxins ie PSP and DSP toxins. The results obtained need to be further verified by using standard addition procedures or with certified reference material. It is important to keep in mind that these rapid tests for PSP and DSP only provide screening results. Further testing with reference analytical methods will be required to confirm the results from these rapid tests before the mussels are harvested and sold on market. The rapid tests are suitable for quality control and decision making regarding whether or not it is safe to harvest the mussel crop or if the mussels should be harvested later after purification in the ocean. The results obtained here indicate that Icelandic blue mussels compose well balanced nutritional and trace element levels. A moderate seasonal variation pattern was observed in all measured nutritional parameters. A principal component analysis (PCA) showed that mussels contained higher proportion of fat and protein during spring (May ‐ June). In the autumn the proportion of protein reduced while the proportion of other unknown substances increased. The PCA analysis also revealed a weak positive correlation between protein and fat and a strong negative correlation between protein and other unknown substances. Heavy metal concentrations were generally low. However, elevated levels of cadmium were measured in mussel samples from certain culture sites, which in some cases exceeded the maximum EU limits (1 mg / kg) for cadmium in bivalve molluscs. The fatty acid profile revealed significant levels of omega ‐ 3 polyunsaturated fatty acids such as Eicosapentaenoic (EPA, C20: 5n3) and Docosahexaenoic (DHA, C22: 6n3) as well as Palmitoleate (C16: 1n7), all recognized for their health beneficial effects . This fundamental information proves that Icelandic blue mussels is a market competitive product of high quality and will greatly aid in developing the Icelandic mussel industry and in making the best choices considering growing, harvesting, marketing and selling their products.

View report

Reports

Evaluation of antibacterial and antioxidant properties of different chitosan products

Published:

01/12/2011

Authors:

Hélène L. Lauzon, Patricia Yuca Hamaguchi, Einar Matthíasson

Supported by:

AVS (contract R 11 074‐11)

Evaluation of antibacterial and antioxidant properties of different chitosan products

In this study, the bactericidal and antioxidant properties of twelve different chitosan substances from Primex ehf. The effect of viscosity / molecular weight (150-360 KDa) and the degree of deacetylation (A = 77‐78%; B = 83‐88%; C = 96‐100%) on the activity of the substances were assessed. The effect of pH (6 and 6.5) and temperature (7 and 17 ° C) on bactericidal activity was also examined. Antioxidant activity was assessed by four methods: oxygen radical absorbance capacity (ORAC), ferrous ion chelating ability, reducing power and DPPH radical scavenging ability. Variable antioxidant activity was found in different chitosan substances. A1 had the highest but actually slight reducing and binding properties, while B3 and B4 had the highest ORAC values. Chitosans with 96-100% deacetylation had the highest in vitro antioxidant activity, regardless of their molecular weight. Similarly, the bactericidal activity of the chitosan substances varied among the bacterial species studied, in addition to which the pH and temperature effects were different. However, some chitosan substances were found to work well on all bacterial species, eg A3 ‐ B2 ‐ B3 ‐ C1.

This report evaluates twelve different types of chitosan products manufactured by Primex ehf and tested for their antibacterial and antioxidant properties in a suitable carrier solution. This study examined the effect of viscosity / molecular weight (150‐360 KDa) and degree of deacetylation (A = 77‐78%; B = 83‐88%; C = 96‐100%) on the properties evaluated, as well as the influence of pH (6 and 6.5) and temperature (7 and 17 ° C) on the antibacterial activity of the chitosan products. The antioxidant activity was evaluated using four assays: oxygen radical absorbance capacity (ORAC), ferrous ion chelating ability, reducing power and DPPH radical scavenging ability. The different chitosan products had different antioxidant properties. A1 had both some reducing and chelating ability, while B3 and B4 had some oxygen radical absorbance capacity. The radical scavenging ability of high DDA (96‐100%) chitosan products was emphasized. Similarly, the antibacterial activity of the different chitosan solutions differed among the bacterial species evaluated as well as pH and temperature conditions. Nevertheless, some products demonstrated antibacterial activity towards all strains tested: mainly A3 ‐ B2 ‐ B3 ‐ C1.

Report closed until 01.01.2014

View report

Reports

Method development and screening for enteric viruses in food and water - 2011 / Method development and screening for enteric viruses in food and water - 2011

Published:

01/12/2011

Authors:

Sveinn H. Magnússon, Eyjólfur Reynisson, Viggó Þór Marteinsson

Contact

Viggó Marteinsson

Research Group Leader

viggo@matis.is

Method development and screening for enteric viruses in food and water - 2011 / Method development and screening for enteric viruses in food and water - 2011

Hepatitis viruses, especially noroviruses, are one of the most common causes of foodborne infections in the West. They are transmitted through faecal contaminated water, food and humans. The aim of the project is to develop a methodology for the analysis of enteric viruses in water and food and to use these methods for the analysis of viruses in the environment and food in Iceland. This report describes work on the project in 2011. An examination was made of whether the established method for the analysis of enteric viruses in drinking water was useful for the analysis of enteric viruses in surface water. The tests were successful and subsequently screening for noroviruses and hepatitis A viruses caused by rivers and streams in the vicinity of Reykjavík. As far as we know, environmental screening for enteric viruses has not been carried out in Iceland until now. The results of that screening showed that noroviruses were found in many surface waters in the vicinity of settlements. Work was also carried out on the implementation of methods for the analysis of noroviruses in shellfish and participation in comparative tests carried out by CEFAS in the United Kingdom in that context. This work showed that the methodology was somewhat deficient, but the virus could not be detected in contaminated shellfish. This problem probably lies in the RNA isolation step of the method and it is hoped that a new system for isolation of viral nucleic acid (MiniMag, Biomérieux) that Matís has recently purchased will solve these shortcomings.

Enteric viruses, particularly norovirus, are the most common cause of foodborne illness in industrialized countries. The viruses are transmitted by fecally contaminated waters, foods and from person to person. The aims of this project are the development of methods for the detection of enteric viruses in foods and water, and the implementation of those methods for studies of enteric viruses in foods and environment in Iceland. This report describes work within the project during 2011. The applicability of the analysis method for enteric viruses in drinking water was tested for surface waters. These testing gave promising results and showed that the method could be used for detecting enteric viruses in environmental waters. Environmental screening was performed to study the prevalence of norovirus and hepatitis A virus in surface waters around Reykjavík. The results of the screening showed that norovirus was commonly found in streams and rivers in proximity of inhabited areas. Analysis methods for the detection of enteric viruses was implemented and tested by participating in a proficiency test supervised by CEFAS, UK. Those results showed the method to be somewhat lacking and no norovirus could be detected in contaminated shellfish. Newly acquired setup for the extraction of viral nucleic acid (Minimag, Biomérieux) is expected to resolve the current shortcomings of the method.

Report closed until 01.01.2014

View report
EN
IS EN