Screening of potential antioxidant activities of water and 70% acetone extracts from ten species of Icelandic seaweeds was performed using three antioxidant assays. Significant differences were observed both in total phenolic contents (TPC) and antioxidant activities of extracts from the various species evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, oxygen radical absorbance capacity (ORAC) and ferrous ion- chelating ability assays. Acetone extracts from three Fucoid species had the highest TPC and consequently exhibited the strongest radical scavenging activities. High correlation was found between TPC of seaweed extracts and their scavenging capacity against DPPH and peroxyl radicals, indicating an important role of algal polyphenols as chain-breaking antioxidants. However, water extracts generally had higher ferrous ion-chelating activity than 70% acetone extracts and no correlation was found with their TPC, suggesting that other components such as polysaccharides, proteins or peptides in the extracts were more effective chelators of ferrous ions than phenolic compounds.
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Aims: The genetic diversity of Campylobacter isolated from human infection and from poultry was assessed in strains originating in three different European regions in order to compare these two hosts and to investigate European regional differences.
Methods and Results: Randomly chosen isolates originated from Norway, Iceland and Basque Country in Spain were genotyped by sequencing of the short variable region (SVR) of flaA. A total of 293 strains were investigated, c. 100 per country with half originated from either host. The results indicate extensive diversity in both hosts and identified differences in the nature and distribution of genotypes between the countries. These differences could in part be related to geographical location, in that Campylobacter genotypes from Iceland and Norway were more similar to each other than either was to Basque Country.
Conclusions: Differences between the countries exceeded the observed differences between human and poultry isolates within a country.
Significance and Impact of the Study: Regional differences are extensive and should not be ignored when comparing genotyping data originating from different international studies.
The aim of these experiments was to evaluate the effect of brining, modified atmosphere packaging (MAP), and superchilling on the quality changes of cod loins as measured by microbial, sensory, and chemical analysis. Unbrined and brined (2.5 ± 1.0% NaCl) cod loins were kept in styrofoam boxes (air) and under modified atmosphere (MA, CO2/ O2/ N2: 50/5/45) at 0, −2, and −3.6 ° C. Samples were examined over a 4-wk period. Total viable psychrotrophic counts and counts of H2S-producing bacteria reached higher numbers in the air-packed brined fish at −2 and −3.6 ° C than in comparable unbrined groups, being significantly different (P <0.05) at the lower temperature. However, lower counts of these bacteria were obtained in the brined MAP fish than in comparable unbrined fish. Counts of Photobacterium phosphoreum increased most rapidly in air- and MA-packed loins kept at 0 ° C. Lower counts were found at superchilled temperatures. According to sensory analysis the shelf life of unbrined air-packed loins was about 11 d at 0 ° C and 14 to 15 d at −2 ° C. The shelf life of MA-packed unbrined loins was about 14 to 15 d at 0 ° C but 21 d at −2 ° C. Thus, synergism of combined superchilling (−2 ° C) and MA led to a considerable shelf life increase for unbrined loins despite the fact that processing and packaging took place 4 to 5 d post-catch. The shelf life of air-packed brined loins at −2 ° C was 12 to 15 d but only 13 d below MA. The same synergistic effect did therefore not apply to brined loins as with unbrined ones.
Background
The bacteriology during storage of the North Atlantic cod has been investigated for the past decades using conventional cultivation strategies which have generated large amount of information. This paper presents a study where both conventional cultivation and cultivation independent approaches were used to investigate the bacterial succession during storage of cod loins at chilled and superchilled temperatures.
Results
Unbrined (0.4% NaCl) and brined (2.5% NaCl) cod loins were stored at chilled (0 ° C) and superchilled (-2 and -3.6 ° C) temperatures in air or modified atmosphere (MA, % CO2/ O2/ N2: 49.0 ± 0.6 / 7.4 ± 0.2 / 43.7 ± 0.4). Discrepancy was observed between cultivation enumeration and culture independent methods where the former showed a general dominance of Pseudomonas spp. (up to 59%) while the latter showed a dominance of Photobacterium phosphoreum (up to 100%).
Gas chromatography-mass spectrophotometry (GC-MC) showed that trimethylamine was the most abundantly volatile in mid- and late storage periods. Terminal restriction polymorphism (t-RFLP) analysis showed that the relative abundance of P. phosphoreum increased with storage time.
Conclusion
The present study shows the bacteriological developments on lightly salted or non-salted cod loins during storage at superchilled temperatures. It furthermore confirms the importance of P. phosphoreum as a spoilage organism during storage of cod loins at low temperatures using molecular techniques. The methods used compensate each other, giving more detailed data on bacterial population developments during spoilage.
Atlantic herring (Clupea harengus) is an important commercial fish and shows to be more and more demanded for human consumption. Therefore, it is very important to find good methods for monitoring the freshness of the fish in order to keep it in the best quality for human consumption. In this study, the fish was stored in ice up to 2 weeks. Quality changes during storage were assessed by the Quality Index Method (QIM), quantitative descriptive analysis (QDA) and Torry scheme, by texture measurements: puncture tests and Texture Profile Analysis (TPA) tests on texture analyzer TA.XT2i, and by electronic nose (e-nose) measurements using FreshSense instrument. Storage time of herring in ice could be estimated by QIM with ± 2 days using 5 herring per lot. No correlation between instrumental texture parameters and storage time or between sensory and instrumental texture variables was found. E-nose measurements could be used to detect the onset of spoilage.
In 2006, we sampled the anoxic bottom waters of a volcanic lake beneath the Vatnajökull ice cap (Iceland). The sample contained 5 × 105 cells per ml, and whole-cell fluorescent in situ hybridization (FISH) and PCR with domain-specific probes showed these to be essentially all bacteria, with no detectable archaea. Pyrosequencing of the V6 hypervariable region of the 16S ribosomal RNA gene, Sanger sequencing of a clone library and FISH-based enumeration of four major phylotypes revealed that the assembly was dominated by a few groups of putative chemotrophic bacteria whose closest cultivated relatives use sulfide, sulfur or hydrogen as electron donors, and oxygen, sulfate or CO2 as electron acceptors. Hundreds of other phylotypes are present at lower abundance in our V6 tag libraries and a rarefaction analysis indicates that sampling did not reach saturation, but FISH data limit the remaining biome to <10–20% of all cells. The composition of this oligarchy can be understood in the context of the chemical disequilibrium created by the mixing of sulfidic lake water and oxygenated glacial meltwater.
The Open University at RU has entered into a co-operation agreement with Matís and the Reykjavík Academy on the development of courses and study lines as well as teaching, in order to strengthen education in the Icelandic economy.
Progressive training and education of managers, specialists and company employees enables them to excel in competition and be creative in times of change.
Co-operation agreements were signed between the Open University, the Reykjavík Academy and Matís at 12:30 today at Reykjavík University.
"The Open University prides itself on offering the Icelandic economy access to powerful professionals and is pleased to be able to add disciplines to the current offer of the Open University through collaboration agreements with Matís and the Reykjavík Academy," says Guðrún Högnadóttir, Executive Director of the Open University, about the collaboration.
"In the work of the Reykjavík Academy, it is important to find ways to share the knowledge of the scholars who work there and utilize it in various ways. In the current crisis in society, there is a widespread revision of the basic ideas of business and society. In collaboration with the Open University, the Reykjavík Academy is participating for the first time in education for the business community, and there is no doubt that mutual acquaintances will enrich everyone who participates, " says Viðar Hreinsson, executive director of the Reykjavík Academy.
Sjöfn Sigurgísladóttir, CEO of Matís, emphasizes that this co-operation agreement fits in very well with Matís 'operations, as one of Matís' goals is to establish strong teaching and re-education, for example through co-operation with universities in Iceland and other educational institutions. "In this way, a strong connection is created between scientific work and research on the one hand and the business community on the other."
Through the collaboration, the Open University wants to enrich Icelandic society by disseminating and harnessing knowledge outside the traditional study lines at the university level. Through targeted training and education of employees, Icelandic companies can meet the changed business environment in a more dynamic way than before.
For further information, please contact Halldóra Guðrún Hinriksdóttir, Director of the Open University, tel. +354 864 0073.
Contact
Margeir Gissurarson
Strategic Scientist
margeir.gissurarson@matis.is
Improved processing of capelin roes
The processing of capelin roe is largely based on research and development that took place between 1972 and 1982. The weakness of the processing process has been the drying of the roe, where roe is left in pots for up to 20 hours where excess water is allowed to leak. . The drying method disrupts the continuity of processing, is costly and increases the risk of microbial growth in the product. The report discusses the effect of processing factors on the chemical and physical properties of capelin roe, as well as the results of experiments with continuous drying during the processing of capelin roe.
Current processing technique of Capelin roes is based on research and development carried out in 1972 to 1982. The weakness of the current process is the drying procedure where the roes are allowed to stand for up to 20 hours while excess water drains off to desirable level. This drying process disturbs the continuity of the process, is costly and increases the risk of bacteria growth. This report discusses the influence of various processing steps on the physical and chemical composition of the Capelin roes and results from experiments with continuous drying procedures in the processing of Capelin roes.
Report closed until 01.07.2011
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Contact
Sigurjón Arason
Chief Engineer
sigurjon.arason@matis.is
Processing in line boats / Processing in line boats
This project is a collaborative project of the following companies; Matís, Brim, Samherji, Vísir and 3X Technology. The aim of the project is to improve the processing processes of longline vessels with a view to reducing the cost of processing, increasing work efficiency and product quality. The project includes the results of a voyage with the icefish trawler Stefni ÍS, where the goal was to perform different refrigeration and bleeding experiments on cod and thus find out what is the best processing method / processing treatment with regard to the quality of the product. The processing deck on longliners will be designed differently, but the same units are used to maximize the quality of the catch. Several groups were taken who received different processing treatments on board. The groups then went to the processing of Hraðfrystihús Gunnvarar where they underwent a sensory evaluation test in the color and release of the fillets. The main results of the project showed that bleeding in the sea, preferably with a lot of water change, before cooling, gives a better color - the meat quality of the wreck. There was no significant difference between the groups in terms of loss, as they all had similar results.
This project is a collaboration work between; Matis, Brim, Samherji, Vísir and 3X Technology. The object of this project is to improve the process in line boats, by reducing production costs, improve working conditions and product quality. This project includes payoff from voyage with the ice-fresh trawler Stefnir ÍS, where the objective was to carry out difference bleeding and cooling methods on cod and find out which methods is efficient regards to the quality of the product. The processing deck in line boats will be implement difference, but same unitary will be used to increase the quality of the catch. The primary conclusion from the research on board Stefnir, is that bleeding in sea before cooling the fish, gives better results regard to the color of the fillet. The research also shows that there was not a significant difference between groups regards to results in looseness of the fillet.
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Contact
Guðjón Þorkelsson
Strategic Scientist
gudjon.thorkelsson@matis.is
Pure muscle proteins from fish
Extensive research was carried out into the physical properties of muscle proteins from fish, especially cod. The project Pure muscle protein from fish proved to be another main support for the operations of Iceprotein ehf. during the company's formative years. The report describes the main results in the production process of refined muscle proteins from cuts and blueberries for use in fillets and ready-made products and the development that took place at Iceprotein ehf. when scaling up. The company Iceprotein is almost the result of the work that was put into the project. Fishballs were produced that were later eaten and evaluated and came out well in various ways, fishballs with isolated proteins as well as minced fish deteriorated less during cooking than fishballs that did not contain isolated proteins.
Great effort was used in viscoelastic measurements of cod muscle proteins. The project Pure muscle protein from fish proved to be one of the main pillars in the operations of Iceprotein ehf. in the offset of the company. In this report main results of the scale-up process at Iceprotein are followed through. The company Iceprotein basically spun off from the work done in this project. Fish balls from fish mince and fish protein isolates were prepared cooked, consumed and analyzed, fish balls containing FPI showed less weight loss in cooking than fish balls that did not contain FPI.