Reports

Optimized Chilling Protocols for Fresh Fish

Published:

01/12/2010

Authors:

Björn Margeirsson, Hélène L. Lauzon, Lárus Þorvaldsson, Sveinn Víkingur Árnason, Sigurjón Arason, Kristín Líf Valtýsdóttir, Emilía Martinsdóttir

Supported by:

AVS R&D Fund of Ministry of Fisheries in Iceland, the Technology Development Fund at the Icelandic Center for Research, University of Iceland Research Fund and EU (contract FP6-016333-2)

contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Optimized Chilling Protocols for Fresh Fish

Guidelines for cooling fresh fish describe the most effective cooling methods at all stages of the cooling chain, with an emphasis on white fish. It describes how to best cool and maintain temperatures in order to maximize product quality and safety and reduce costs and energy consumption. The report contains background information for instructions in the information source Kæligátt on Matís' website, which is presented in a user-friendly way in Icelandic www.kaeligatt.is and English www.chillfish.net. The guidelines are intended for fishermen, manufacturers, carriers and other members of the value chain. The guidelines are based on research that has been carried out within research projects such as Chill ‐ on, Simulation of cooling processes and Cooling improvement. The main chapters deal with refrigeration on board, during processing, during packing, transport and storage of fish.

The overall aim of the optimized chilling protocols is to describe the most effective chilling methods for any stage in the food supply chain with emphasis on whitefish. This comprises optimization of the whole chain for lowering and maintaining low temperature with the aim of maximizing quality and safety of the products and minimizing costs and energy use. This report is the background for the protocols and guidelines published with open access at Matís website in Icelandic and English in a user ‐ friendly way: www.chillfish.net. These are protocols to follow aimed at the use of fishermen, manufacturers, transporters and other stakeholders in the fisheries chain. The information is divided into subchapters of different links in the chain. How to chill fish on ‐ board, during processing, packaging, transport and storage are the main chapters.

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Reports

Overview on fish quality research - Impact of fish handling, processing, storage and logistics on fish quality deterioration

Published:

01/11/2010

Authors:

Hélène L. Lauzon, Björn Margeirsson, Kolbrún Sveinsdóttir, María Guðjónsdóttir, Magnea G. Karlsdóttir, Emilia Martinsdóttir

Supported by:

AVS R&D Fund of Ministry of Fisheries in Iceland, Technology Development Fund and EU IP Chill-on (contract FP6-016333-2)

contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

Overview on fish quality research - Impact of fish handling, processing, storage and logistics on fish quality deterioration

The short shelf life of fish is a limiting factor in the export of fresh fish products from Iceland. The initial quality of raw materials, methods of cooling, processing, packaging and conditions during storage and transport are discussed, as well as the effects of all these factors on the freshness and shelf life of fish products. Temperature control is very important to maintain the quality of the fish. Pre-processed fillets have been used to lower the pre-packing temperature. However, care must be taken that the pre-cooling technology does not endanger the microbial condition of the product and thus causes it to be damaged earlier after packaging. The synergistic effects of supercooling and aerated packaging (MAP) can significantly extend the freshness period and shelf life of fish products. Furthermore, packaging methods are examined, including new, more environmentally friendly packaging. Finally, the effect of transport routes of fresh fish products on their final quality to consumers in the market is discussed. This report provides an overview of the research of the Fisheries Research Institute and Matís ohf over the past three decades on the subject. Furthermore, it is discussed how these results can benefit the fishing industry.

The limited shelf life of fresh fish products is a large hurdle for the export of fresh products from Iceland. The influence of raw material quality, cooling methods, processing, packaging and storage conditions on freshness and shelf life extension is discussed. Temperature control is important to maintain fish quality. Pre-cooling of fillets in process has been used to lower the temperature prior to packaging. However, the cooling technique applied should not compromise the microbiological quality of the product and render it vulnerable to faster spoilage postpackaging. Synergism of combined superchilling and modified atmosphere packaging (MAP) can lead to a considerable extension of the freshness period and shelf life of fish products. Further, alternative and environmentally-friendly packaging methods are considered. Finally, the impact of transportation mode of fresh fish products on their resulting quality is examined. This report provides an overview of the findings on fish research carried out at Matís (Icelandic Fisheries Laboratories) over the last three decades and further discusses their practicality for the fish processing industry.

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Reports

Comparison of cooling techniques - Their efficiency during cooling their effect on microbial and chemical spoilage indicators

Published:

01/10/2010

Authors:

Lárus Þorvaldsson, Hélène L. Lauzon, Björn Margeirsson, Emilía Martinsdóttir, Sigurjón Arason

Supported by:

EU (contract FP6‐016333‐2) Chill ‐ on

contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Comparison of cooling techniques - Their efficiency during cooling their effect on microbial and chemical spoilage indicators

The aim of the experiments was to investigate the effects of different types of ice during cooling and storage of whole, gutted fish on heat and damage processes. Three types of ice were used: traditional crushed plate ice ("flake ice") (referred to as PI here) as well as two types of ice scrapers (liquid ice) produced in specially designed ice scrapers (referred to as LIA and LIB here) with different salt and ice ratios. The results of temperature measurements showed much faster cooling with an ice scraper than conventional flake ice. Then cooling down proved to be somewhat faster with one type of ice scraper (LIB) than the other (LIA) because the temperature of haddock cooled in LIB went from 7.5 ° C down to 0 ° C in 20 - 30 min compared to about 55 - 60 min in LIA. The corresponding time for traditional flake ice was about 260 min. The difference in cooling time in the LIA and LIB can be partly explained by the 10% heavier fish in the LIA group. Cooling whole haddock from 10 ° C and 20 ° C gave similar results as cooling it from 7.5 ° C. Cooling time from 10 ° C to 4 ° C was 24 min for the LIB group and 36 min for the LIA group. The comparable cooling time from 20 ° C to 4 ° C was 46 min for LIB compared to 55 min for LIA. The results of microbiological measurements by cultivable methods showed that little growth of specialized pests (SSÖ) on haddock skin occurred early in the storage period, regardless of the cooling method. With further storage, microbial growth was similar between the cooling groups with an ice layer at the top of the vessel. Comparable microbial growth was observed in the flesh until on day 8, a significantly higher number of Photobacterium phosphoreum and H2S-producing bacteria were found in LIB-chilled fish. It is interesting to note that the different temperature profiles measured among the refrigeration groups did not reflect the microbial growth that took place. In fact, SSÖ's damage capacity did not appear to be less in the coldest conditions during the storage period, as significantly higher levels of TVB-N and TMA were measured in fish treated with ice scraping compared to conventional ice storage. It is possible that the conditions created by these waterlogged and salted conditions when using ice scrapers are undesirable and lead to a faster damage process than occurs under icy conditions.

The aim of study was to investigate the effects of different ice media during cooling and storage of whole, gutted whitefish on temperature control and spoilage indicators. The thermodynamic, microbial and chemical properties of whole, gutted haddock were examined with respect to the cooling medium in which it was stored. Three basic types of cooling medium were used: traditional crushed plate ice (PI + PI) and two types of commercially available liquid (slurry) ice, here denoted as LIA and LIB. The ice types were furthermore divided into five groups with different salinity and ice concentration. Microbiological analysis by cultivation methods revealed that growth of some specific spoilage organisms (SSO) on fish skin was delayed at early storage, independently of the cooling methods. With further storage, little or no difference in counts was seen among traditionally iced fish and those cooled in liquid ice for 2 h before draining and top layer icing. Even less difference was observed in the flesh microbiota developing until significant growth increase in Photobacterium phosphoreum and H2S ‐ producing bacteria was seen on day 8 in LIB cooled fish. Interestingly the differences obtained in the temperature profiles of fish cooled differently were not supported by different bacterial growth behavior. In fact, SSO spoilage potential was not reduced in the coolest treatments as time progressed, as demonstrated on day 8 by the significantly higher TVB ‐ N and TMA content of fish cooled in liquid ice compared to traditional icing. Conditions created by liquid ice environment (salt uptake of flesh) may have been unfavorable, causing an even faster fish deterioration process with increasing storage time compared to traditional ice storage. Evaluation of the thermodynamic properties showed that LIB gave slightly faster cooling than LIA. For haddock stored in LIB the flesh reached 0 ° C in 20‐30 min, but it took 57 min in LIA and around 260 min in crushed plate ice (PI). The difference in the cooling rate of LIA and LIB might, apart from the physical properties of the ice, be partially explained by the fish weight, being on average 10% more in the LIA group. The additional cooling rate experiments where whole, gutted haddock was cooled down from 20 ° C and 10 ° C gave similar results. When cooled down from 20 ° C the haddock reached 4 ° C in 46 min when chilled in LIB while the same process in LIA required 55 min. Similar difference was seen when the material was cooled down from 10 ° C, where fish chilled in LIB reached 4 ° C in 24 min and fish chilled in LIA reached 4 ° C in 36 min.

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Reports

Muscle spoilage in Nephrops

Published:

01/09/2010

Authors:

Guðmundur H. Gunnarsson

Supported by:

AVS Research Fund and NORA

Muscle spoilage in Nephrops

The project worked with the lobster industry in Iceland to identify the causes and define solutions to reduce muscle necrosis in lobster. Such myocardial infarction had increased greatly in recent years for no apparent reason. Initially, it was thought that the probable cause of the muscular dystrophy was a Hematodinium infection in the strain, but such an infection has caused considerable shocks in the Scottish lobster strain. It was confirmed that there was no association between Hematodinium infection and myocardial infarction. Subsequently, the emphasis of the project had to be changed. Extensive morphological studies of lobster were able to link muscle necrosis to enzyme activity in lobster hepatopancrea. Based on these results, a solution was defined to reduce the incidence of myocardial infarction. With improved cooling and treatment with enzyme inhibitors, muscle lobster necrosis has been significantly reduced.

This project was carried out in close association with the Icelandic Nephrops fishing and processing industry. The aim was to define reasons and propose solutions to reduce muscle spoilage in Nephrops. Such muscle spoilage had increased significantly during the last few years without any know reason. The original hypothesis of the project was that there might be a correlation between infection of the parasite Hematodininum and muscle spoilage. Such parasitic infection has resulted in lower quality products in the Scottish Nephrops industry for the last decade. In the project it was confirmed that such infection is not the underlying factor for muscle spoilage. This resulted in a change of direction in the project. Based on morphological analysis of Nephrops it was observed that the muscle spoilage was correlated with enzyme activity in the hepatopancrea. Based on this observation it was possible to propose a code of practice to reduce the onset of muscle spoilage. The code of practice is based on improved chilling and use of enzyme inhibitor during the storage of the Nephrops from catch to frozen product.

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Reports

Reform of the food value chain. Effects of the cold chain on the shrinkage of meat / Improvements in the food value chain. Influence of the chill chain on impairment of meat product

Published:

01/03/2010

Authors:

Þóra Valsdóttir, Jón Haukur Arnarson, Óli Þór Hilmarsson

Supported by:

Technology Development Fund

contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Reform of the food value chain. Effects of the cold chain on the shrinkage of meat / Improvements in the food value chain. Influence of the chill chain on impairment of meat product

This report covers one part of the Food Value Improvement Project, the main objective of which is to identify where in the food value chain shrinkage is taking place and to define measures to minimize the waste resulting from the shrinkage. In this section, emphasis was placed on examining the effect of temperature on shrinkage in relation to the main steps in the process of chilled meat products from producers until they reach consumers.

This report discusses a part of the project Improvements in the food value chain. The main aim of the project was to analyze where in the value chain waste is created and define actions to reduce it. In this part emphasis was put on the influence of temperature on impairment of chilled meat products in respect to the different steps in the supply chain.

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Reports

Reform of the food value chain. Proposal for project descriptions for the meat value chain / Improvements in the food value chain. Propositions for managing the meat chill chain

Published:

01/03/2010

Authors:

Þóra Valsdóttir, Jón Haukur Arnarson, Óli Þór Hilmarsson, Hlynur Stefánsson

Supported by:

Technology Development Fund

contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Reform of the food value chain. Proposal for project descriptions for the meat value chain / Improvements in the food value chain. Propositions for managing the meat chill chain

This report covers one part of the Food Value Improvement Chain project, the main objective of which is to identify where in the food value value chain waste is occurring and to define measures to minimize the waste resulting from the waste. This section sets out proposals for improved procedures to improve the production and transport processes of chilled meat products, with the main emphasis on temperature control in the process. The project descriptions are based on requirements set by regulations, official guidelines and research results. The rules of procedure are divided into three parts; production, transport and retail. No project descriptions are made for specific processing methods.

This report discusses a part of the project Improvements in the food value chain. The main aim of the project was to analyze where in the value chain waste is created and define actions to reduce it. In this part propositions are made for good practices in relation to the meat chill chain. The propositions are based on regulation requirements; good manufacturing guidelines and research conclusions. They are divided into three main parts; processing, transport and retail. Specific processing methods are not included.

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Reports

Processing in line boats / Processing in line boats

Published:

01/06/2009

Authors:

Róbert Hafsteinsson, Albert Högnason, Sigurjón Arason

Supported by:

AVS, Technology Development Fund

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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Reports

Processing and quality control of farmed cod

Published:

01/04/2009

Authors:

Kristín Anna Þórarinsdóttir, Valur Norðri Gunnlaugsson, Guðrún Anna Finnbogadóttir, Kristján Jóakimsson, Sigurjón Arason

Supported by:

AVS R26-06 / AVS R&D Fund of Ministry of Fisheries in Iceland

contact

Valur Norðri Gunnlaugsson

Group Leader

valur.n.gunnlaugsson@matis.is

Processing and quality control of farmed cod

The report is a summary of the results of the project "" Processing and quality control of farmed cod "which was carried out in collaboration between HG and Matís. Ways were sought to develop traditional methods for the production of fresh, frozen and lightly salted products so that they could be used for farmed fish. The aim of the project was to provide products from farmed cod with valuable and varied products that met the quality requirements of the market. Processing of farmed cod must be carried out before death. Otherwise there is a risk that the formation will be so great that the products will in the worst case be unsaleable. Chilled and loose-frozen products are of comparable quality to products made from wild cod. However, the properties are not the same and this is reflected in the taste and texture properties, among other things. Wild cod is coarser and often juicier, but farmed cod has a more meaty and stuttering texture and is sweeter in taste. Processing for death solidification means that traditional salting processes for farmed fish cannot be used. In light salting, methods such as injection and prolongation of the pickling time can be used to reduce the negative effects of lethal stiffness on uptake during normal course of action. Salting and temperature conditions need to be very well controlled to minimize the risk of microbial growth as very low salinity is used in the production of lightly salted (2% salt) products.

This report summarizes the results from the project "Processing and quality control of farmed cod" where processing and salting methods for farmed cod were developed in co-operation of HG (HradfrystihusidGunnvor Ltd) and Matís ohf. The main difference in processing of farmed and wild cod is that farmed cod has to be processed before rigor mortis. Otherwise there is a high risk of gaping and quality defects in products that are not accepted by markets. Chilled and IQF products processed from pre-rigor farmed cod were of similar quality as products from wild cod. However, farmed cod products have different properties, they have a sweeter taste and more "meaty" and firmer texture than products from wild cod which are softer and juicier. Processing of farmed cod before rigor retards weight increase and salt uptake during light salting. The effects of rigor can be reduced using brine injection and increasing brining time from traditional processed for farmed cod. Salting conditions and temperature must be carefully controlled during the process to avoid microbial growth at the low salt levels used in production of light salted (2% NaCl) products.

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Reports

Assessment of slaughter in sheep slaughterhouses in the autumn of 2008

Published:

10/02/2009

Authors:

Valur Norðri Gunnlaugsson, Óli Þór Hilmarsson, Ásbjörn Jónsson, Guðjón Þorkelsson

Supported by:

National Association of Sheep Farmers

contact

Valur Norðri Gunnlaugsson

Group Leader

valur.n.gunnlaugsson@matis.is

Assessment of slaughter in sheep slaughterhouses in the autumn of 2008

The Annual General Meeting of the National Association of Sheep Farmers decided in April 2008 that a detailed assessment will be made of the treatment of lamb at slaughter, especially during killing and cooling. An explanatory memorandum to the resolution stated: "The meeting considers it necessary to examine the possible effects of these two factors on the quality of the meat. When the animal is killed by electricity, there is a risk that the carcasses will not be able to bleed sufficiently and there is a risk of cooling hardening with too rapid cooling or freezing. Matís ohf. carried out an assessment of the above factors in the autumn of 2008 where the killing and cooling processes in 6 slaughterhouses were examined, of which one house was visited twice. Monitor the killing of 100 carcasses in each house to see procedures and take out facilities. The acidity and temperature of the carcass were measured regularly as well as the temperature in the slaughterhouses of the slaughterhouses. Carcasses taken in this study followed jogging through the normal process of action in each slaughterhouse, but before freezing, the backbone was removed and frozen. Vertebral muscles were then used in texture measurements to see different gravitational processes between slaughterhouses on the meat of the meat. The results show that the killing method affects the death stiffening process. It was much further in the carcasses of lambs in houses that use the "head-back" method than in houses that had a head clip. Cooling time is clearly too short in some houses. Thus the freezing temperature was highest as it was shortest and well above 6.0 in the house where it was only 4 hours. The viscosity of the meat was lowest in the vertebral carcasses from the slaughterhouse, where the head-back killing method was used, electrical stimulation was used and extensive and long cooling ensured that the meat was almost completely tenderized.

At annual general meeting of sheep farmers association in 2008 was concluded that a general observation ought to take place on treatment of lamb meat at slaughterhouses, particularly at electrocute step and the cooling phase. The aim was to see the influence of these factors on meat quality. Matis ohf. visited 6 slaughterhouses in autumn 2008. The results showed that the electrocution method affected the pH of carcasses. In some slaughterhouses the cooling phase was too short and therefore the pH was too high in carcasses when they were frozen. The tenderest meat came from the slaughterhouse where the meat was electrically stimulated and there was a long cooling paste.

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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.

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