Reports

Fatty saithe products / Fat ‐ skinning of pollock

Published:

01/09/2009

Authors:

Ragnheiður Sveinþórsdóttir, Hörður G. Kristinsson, Jónína Jóhannsdóttir, Arnljótur Bjarki Bergsson

Supported by:

AVS

Fatty saithe products / Fat ‐ skinning of pollock

The aim of this project was to investigate whether value-adding of saithe fillets could be increased in value. With fat removal, it could be possible to divide saithe fillets into white and valuable neck pieces and by-products that are tail pieces, red and brown cuts.

The project included:

Examined the quality difference between ordinary and fatty saithe fillets with sensory evaluation.

• Chemically analyzed the brown layer that is on the skin of saithe but it was peeled off in the project.  

• Explored ways to utilize by-products.

Examined utilization in traditional filleting and fat skinning.

The objective of this project is to explore if it´s possible to increase the value of pollock when fat ‐ skinning it. When fat ‐ skinning pollock it is possible to split a pollock fillet into white fillet and by ‐ products like tail, skin and brown layer.

In this project was:

• Quality explored for normal pollock fillets and fat ‐ skinned pollock fillets.

• The brown layer we fat ‐ skinned from the fillet was analyzed.

• We explored how to yield the byproducts.

• Difference of normal filleting and fat ‐ skinning explored.  

View report

Reports

Equalization - increased quality and improved properties of fish mince / Homogenization - increased value of fish mince

Published:

01/05/2009

Authors:

Kristín Anna Þórarinsdóttir, Magnea G. Arnþórsdóttir, Irek Klonowski, Arnljótur Bjarki Bergsson, Sindri Sigurðsson, Sigurjón Arason

Supported by:

AVS R 011‐08 / AVS R&D Fund of Ministry of Fisheries in Iceland TÞS 071321007 /Technology Development Fund, RANNIS ‐ Icelandic Center for Research

Contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Equalization - increased quality and improved properties of fish mince / Homogenization - increased value of fish mince

The aim of the project was to develop a new production method for marrow mixture for injection into fish products based on leveling. The process gave good results in terms of stability, water resistance, appearance and sprayability of the mixture. The effects on micro-organisms varied according to the processes used and the raw materials, but they were not in all cases noticeable. The utilization and stability of the injected products increased significantly compared to untreated fillets and fillets injected with pure brine. Freezing significantly reduced the water resistance of the muscle. However, the benefit of the injection was in terms of total weight changes from processing until after thawing on the one hand and welding on the other. The report is a summary of experiments in the project "Membrane explosion - increased quality and improved properties of marrow". 

The aim of the project was to develop a process for homogenization of fish mince in solution for injection in fish products. The process was well suited for preparing a solution which had the right particle size, viscosity, water holding properties and stability for injection. The yield and stability of the protein injected fillets was increased compared to untreated fillets and fillets injected with pure salt brine. Freezing reduced water holding capacity but the yield was still higher than of untreated fillets, both after thawing and cooking.

View report

Reports

Combined Blast and Contact cooling - Effects on physiochemical characteristics of fresh haddock (Melanogrammus aeglefinus) fillets

Published:

01/06/2008

Authors:

Magnea Guðrún Arnþórsdóttir, Sigurjón Arason, Björn Margeirsson

Supported by:

Tækniþróunarsjóður, AVS

Contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Combined Blast and Contact cooling - Effects on physiochemical characteristics of fresh haddock (Melanogrammus aeglefinus) fillets

Skaginn hf. has a patent for new processing technology for the processing of fresh and frozen fillets based on so-called skin cooling before peeling. The purpose of this research project was to compare fillet processing with skin cooling and traditional fillet processing. The project compares fresh fillets and chilled fillets with regard to utilization, quality and shelf life. Two experiments were performed, on the one hand Experiment I where water resistance, quality, boiling efficiency and appearance were examined, and on the other hand Experiment II where these same factors were examined and the effect of erosive cooling on the shelf life of fresh and frozen haddock was examined. The experiments were carried out at Festi ehf. in Hafnarfjörður. The main results of these studies showed that fillet processing with skin cooling has more advantages than traditional fillet processing. The erosive cooling gives higher utilization and more valuable products with a longer shelf life. Increased shelf life of fresh fish provides increased opportunities for export, which is very important for the fishing industry.

The aim of the project was to compare a new processing technique, CBC, with traditional processing of haddock fillets. In the latter the fillets go through the process without additional refrigeration. In the new processing technique, CBC, the fillets, after filleting and pre-trimming, go through pre-cooler / fluid-ice followed by CBC super-chilling. Two trials were performed, a preliminary experiment (I) and a main experiment (II). In the preliminary experiment (I), water holding capacity, quality and cooking yield were examined. In the main experiment (II) these same factors were examined, in addition to the superchilling effect on extended shelf-life of fresh and frozen haddock fillets. After the pre-cooler step, the fillets gained weight with yields of 101.6% to 102.7%. After the CBC super-chilling the fillets had final yields of 100.3% to 101.2%. After skinning, the fillets without refrigeration (traditional processing) lost most weight. The highest value of cooking yield was obtained in CBC super-chilled fillets with skin. Skinless traditional and CBC super-chilled fillets showed similar cooking yield (P> 0.05). CBC super-chilling increased the total yield of the fillets. The difference between the traditional fillets and the super-chilled fillets was significant. The appearance of the CBC super-chilled fillets was much better and with less gaping than the traditional fillets. The traditional fillets had more ragged outlines, and the ratio of cut-offs after fine-trimming was therefore higher for the traditional fillets than the CBC super-chilled fillets. Appearance of the traditional fillets showed a little yellow tinge which increased during the storage time. The CBC super-chilled fillets had a whiter and more "fresh" appearance and were therefore more attractive. Examination of total bacterial count, and amount of TMA and TVN showed that the CBC super-chilling process can extend the shelf life of fresh haddock fillets.

View report

Reports

Process control for fishing, processing and processing of salted fish. Impact of raw material variables on the utilization and quality of salted fish

Published:

01/08/2007

Authors:

Lárus Þorvaldsson, Þóra Valsdóttir, Sigurjón Arason, Kristín Anna Þórarinsdóttir

Supported by:

AVS, Rannís Technology Development Fund

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Process control for fishing, processing and processing of salted fish. Impact of raw material variables on the utilization and quality of salted fish

Data was collected from Vísir hf. and Þorbjörn hf. and the relationship between utilization and quality with fishing areas, fishing time, fishing vessels, cooling on board and changes in the processing process are assessed. It was found that fishing areas had a significant effect on processing utilization, but the difference in effect utilization and quality by fishing area was smaller. Fluctuations in efficiency and quality proved to be seasonal and there was also a difference between years. Changes in cooling on board, ie. the use of liquid ice instead of flake ice on board did not prove to have a significant effect in the aforementioned manner. On the other hand, changes in the mechanism of action, ie. injection, both utilization and quality. The content of the report was part of the project "Process management for fishing, processing and processing of salted fish".

Analysis of data collected by the fisheries companies Vísir and Thorfish revealed the effects of fishing grounds, season, fishing vessels, chilling methods on board and salting procedure on yield and quality of salted products. Effects of fishing grounds on processing yield were significant but curing yield and quality were less influenced. Variation in curing yield and quality were seasonal and differences between years were observed. Changes in chilling methods on-board, ie use of liquid ice instead of flake ice did not affect yield and quality of salted products. On the other hand, changes in the salting procedure did, when injection was added as the initial step in the process.

View report

Reports

Biodiversity in hot springs in Krísuvík and Gunnuhver in Reykjanes: Research carried out due to the Framework Plan for the utilization of geothermal energy in high-temperature areas

Published:

01/08/2007

Authors:

Sólveig K. Pétursdóttir, Sólveig Ólafsdóttir, Steinunn Magnúsdóttir, Guðmundur Óli Hreggviðsson

Contact

Steinunn Ásbjörg Magnúsdóttir

Project Manager

steinunn.magnusdottir@matis.is

Biodiversity in hot springs in Krísuvík and Gunnuhver in Reykjanes: Research carried out due to the Framework Plan for the utilization of geothermal energy in high-temperature areas

This study of the ecosystem in the hot springs in the Krísuvík area is the third biota assessment carried out within the Framework Program, but the first two dealt with the ecosystem in the hot springs in the Hengill area and in the Torfajökull area.

Emphasis was placed on the thermal area in Seltún, where sampling was joint with the geochemists of the Institute of Earth Sciences, which was the first step in an interdisciplinary approach to the subject, which is hoped for, but is still in its early stages. Other areas that were tried to explore were hot springs by Austurengjahver and the area by Gunnuhver in Reykjanes. The temperature in the hot springs in Seltún was in the range of 53-93 ° C and furthermore one soil sample was reported which was taken at a lower temperature or 34 ° C. The acidity of the hot springs in Seltún was in the range of pH 2.5-6. The temperature in the hot springs at Austurengjahver was between 50-75 ° C and the pH pH 2.4 - 4.3. The temperature in the hot springs at Gunnuhver was measured in the range of 70-90 ° C and the pH pH 3.8 - 4.2. A total of thirteen samples were taken in the above areas and DNA was successfully isolated from seven of them. DNA could not be extracted from the samples at Austurengjahver. Nucleic acid amplification of the 16S rRNA, a species-differentiating gene of the nuclear nucleus, was performed on six samples. Amplification was obtained from all these samples with specific real bacterial indicators, but three with ancient bacterial indicators.

A total of 304 sequences of real bacterial species were obtained in the area known as Seltún. These species are spread over 26 species which in turn are spread over 10 camps. The primitive species of the Aquificeae array house over 80% sequences and are therefore predominant in these samples and are primary producers in the ecosystems of the hot springs. Five species within this array were found in the samples from Seltún. Other species are mainly classified into different groups Proteobacteria (13%) but they are a very diverse group. Other species found are sparsely populated and less important here. A total of 81 sequences of ancient bacterial species were obtained from the Seltún area. Most of them or space 90% are classified as Thermoplasmatales within the Euryarchaeota class, but this is a heat and acid species. Other ancient bacteria in the samples in Seltún belong to the Chrenarchaeota group, mostly to the genus Desulfurococcales.

A total of 56 actual bacterial differentiations were obtained from the hot springs at Gunnuhver. The vast majority of them (about 70%) belong to the primitive class Aquificeae, but about 30% to different groups of Proteobacteria. The ancient bacteria in Gunnuhver are homogeneous as they are all of the genus Sulfolobales which is a very heat and acid group. 1 Overall, it can be said that the area around Seltún shows a typical pattern of a peripheral ecosystem where one species is predominant and other species are spread over various factions. The calculated biodiversity in the samples was relatively low or in the range of 1.0-2.0. For comparison, the same coefficient calculated for samples from the Torfajökull area and at Ölkelduháls was in the range of 1.1-4.7. The environmental conditions of temperature and acidity in Seltún and Gunnuhver are not on the edge, but it is likely that substances and compounds in the hot springs and clay can affect the diversity of the ecosystem, ie. which species get thrive and which do not.

Rare species that had only distant relatives in Genbank were found in the Seltún samples, among others. In most cases, however, there are only 1-2 representatives of the species in question. Most of these distantly related species were classified as Proteobacteria and Acidobacteria.

Matís - Prokaria will probably continue to work on sampling and species analysis in the Krísuvík area. The intention is to include these results in a final summary of the ecosystem in hot springs in Iceland in the last year of the Framework Program.

View report

Reports

Process control for fishing, processing and processing of salted fish. Effects of different salting methods on the effect of cod fillets

Published:

01/07/2007

Authors:

María Guðjónsdóttir, Þóra Valsdóttir, Ása Þorkelsdóttir, Kolbrún Sveinsdóttir, Hannes Magnússon, Sigurjón Arason, Kristín A. Þórarinsdóttir

Supported by:

AVS, Rannís Technology Development Fund

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Process control for fishing, processing and processing of salted fish. Effects of different salting methods on the effect of cod fillets

A comparison was made of the effects of different salting methods on the utilization, quality and other properties of salted cod fillets. One group was only pre-salted but other groups were pre-salted in different ways, ie. by brine salting, spraying and / or pickling. Injured fish had a higher utilization and came out better in quality assessment than uninjected fish. However, the results indicated that the odor and taste of action were higher in unsprayed fish. The effect of phosphate use and spraying on drying properties due to higher water and salt content in products was investigated. It was found that injected fish lost less weight during drying. For the aforementioned reasons, the water content turned out to be higher after drying than in unsprayed fish. The fillets of the dried products varied according to whether the chemical content was based on drying or weight loss on drying. Therefore, the criteria for new salting processes need to be revised and drying processes need to be adapted to the changed properties of salted products.

The effects of different salting processes on yield, quality and other characteristics of salted and cured products were evaluated. Various combinations of salting steps were tested, one group was only dry salted but other groups were first pickle salted, brine injected and / or brine salted. The injected products had higher yield and higher quality than other products. The results indicated that the curing odor and flavor were stronger in products that were not injected. The water and salt content was higher in injected fillets which is important with regard to continuing processes, like drying and rehydration. Measurements during and after drying showed that injection resulted in lower drying rate and higher water content of the fillets. Dried products have been rated in different classes with regard to water content and weight changes during drying. Due to changes in the salting process and drying properties of the salted fish, these reference values have to be reconsidered.

View report

Reports

Process control for fishing, processing and processing of salted fish. Impact of post-catch cooling on utilization and quality (2)

Published:

01/07/2007

Authors:

Þóra Valsdóttir, Karl Rúnar Róbertsson, Egil Þorbergsson, Sigurjón Arason, Kristín Anna Þórarinsdóttir

Supported by:

AVS, Rannís Technology Development Fund

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Process control for fishing, processing and processing of salted fish. Impact of post-catch cooling on utilization and quality (2)

The purpose of the experiment was to investigate the effect of different cooling methods on board a fishing vessel on the quality and utilization of salted fish in terms of whether the fish was filleted or flattened before processing. There has been different experience with the use of liquid ice, but there have been theories that it has a negative effect on quality and utilization. The use of liquid ice in the train was at least worse in terms of quality and utilization compared to flake ice, whether it was processed fillets or flat fish. Discharge was more pronounced in fillets than in flat fish, but it could not be linked to cooling methods on board.

The aim of the trial was to investigate the effects of different cooling methods onboard a fishing vessel on curing characteristics during heavy salting of cod. The fish was either splitted or filleted before salting. It has been claimed the use of liquid ice for cooling of raw material, may lead to lower yield and quality of the products. The results showed that products from fish stored in liquid ice from catch to processing were similar or better than from fish stored in flake ice. Gaping appeared to be more related to fillets than splitted fish, but this factor could not be linked to chilling methods used onboard.

View report

Reports

Process control for fishing, processing and processing of salted fish. Effects of different salting methods on the effect of flat fish

Published:

01/07/2007

Authors:

Kristín Anna Þórarinsdóttir, Þóra Valsdóttir, María Guðjónsdóttir, Sigurjón Arason

Supported by:

AVS, Rannís Technology Development Fund

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Process control for fishing, processing and processing of salted fish. Effects of different salting methods on the effect of flat fish

Flat cod was processed according to different salting processes in order to assess the effect of pre-salting (injection, pickling and brine salting) and the composition of the injection brine (salt, phosphate, fish protein) on the action properties. Pre-salting improved efficiency and overall utilization at all stages, depending on efficacy, dehydration and drying. Brine was better than brine salting but had the most effect of spraying (followed by brine). All groups were post-salted after pre-salting. Products with added proteins came out best in the quality assessment, ie. higher percentage went in SPIG I than in other groups. Effects on microbial growth and degradation (TVN, TMA, TBA) were not significant. Efficacy characteristics assessed by sensory evaluation were similarly similar for all groups, regardless of the salting method.

Different pre-salting methods (injection, brine salting, pickle salting) were used as the initial step in heavy salting of cod. The effects of brine composition (salt, phosphate, fish proteins) were evaluated. Pre-salting increased yield and quality, brine salting was more effective than pickle salting, but the best results were obtained by injection (followed by brine salting. Dry salted was used as the main salting step for all groups. Higher ratio of products with added proteins were graded as the best class (SPIG I). Effects on microbial growth or formation of degradation compounds (TVN, TMA, TBA) were not significant.Sensory analysis showed that curing characteristics (taste, odor, appearance, texture) were not affected by the salting procedure.

View report

Reports

Evaluation of mutton assessment

Published:

01/02/2007

Authors:

Ásbjörn Jónsson, Óli Þór Hilmarsson

Supported by:

Productivity Fund, Executive Committee for Agricultural Contracts

Contact

Óli Þór Hilmarsson

Project Manager

oli.th.hilmarsson@matis.is

Evaluation of mutton assessment

A new meat assessment for mutton according to the EUROP system was introduced in Iceland in the autumn of 1998. According to this, the carcasses are classified according to meat filling on the one hand and fat on the other. In the EUROP system, carcass filling is assessed in five main categories (E, U, R, O and P), where E is best and P is worst. Fat is also assessed in five main categories (1, 2, 3, 4 and 5), where 1 is the least and 5 the most. The fat subcategory, 3+, is also used in Iceland. In the EUROP system, the dilka carcasses are classified much more precisely by fat and body filling than was done in the old system. This precise classification serves both farmers, who get better information about their products, and meat processors who can better choose the type of meat carcass that is suitable for different processing. The aim of this project was to obtain information on the utilization, processing properties and chemical composition of dilka meat and dilka meat products, according to an assessment according to the EUROP system. During the 2003 and 2004 slaughter seasons, the assessment was carried out in three slaughterhouses. Carcasses in the following rating categories were studied: U2, U3, U3 +, U4, R1, R2, R3, R3 +, R4, O1, O2, O3, O3 +, P1 and P2. The right part of the carcass was divided into thighs, spine, beats and forequarters, to determine the ratio of meat, fat and bones. The left half was also disassembled and processed into products. Chemical measurements were performed on products to determine nutritional value. When carcasses were dissected into meat, fat, and bones, the average carcass meat content was 60%, the fat content averaged 19%, and the bone ratio averaged 18 %. Those who worked on the project were employees of Matís ohf. and Stefán Vilhjálmsson, chairman of the meat assessment, together with the employees of the slaughterhouses in question.

A new EU carcass classification system for lamb was introduced in Iceland in 1998. In the new system carcasses were evaluated according to conformation (EUROP classification: five classes, from E = '' good '', to P = '' bad '' conformation ) and fatness score (5 classes, from 1 = lean, to 5 = fat). The EU classification system is more accurate than the previous system and gives farmers more information about their carcasses and enables meat producers to select carcasses according to the different productions. The main objective of this study was to gain information about the utilization, processing quality and chemical combination of the carcasses, according to the new classification system. A study was performed in abattoirs in 2003-2004 according to the classification system. The right half of the carcasses were segmented into legs, loins, flanks and forequarters and then dissected into meat, fat and bone. The left half were segmented and processed further into final products. Chemical analysis was performed on the carcasses to estimate the nutritional value. The average proportion of the meat in the carcasses was 60%, proportion of the fat was 19% and the average bone proportion was 18%. The project was done by employees of Matís, Stefán Vilhjálmsson, chairman of the meat classification board, and the employees of the abattoirs.

View report
EN