Category: Reports

Reports

Catching, processing and export of live ocean clam

Published:

01/11/2010

Authors:

Siggeir Stefánsson, Jónas R. Viðarsson, Þorgrímur Kjartansson, Guðmundur H. Gunnarsson

Supported by:

AVS (project R 061-08)

Contact

Jónas Rúnar Viðarsson

Sviðsstjóri rannsókna

jonas@matis.is

Catching, processing and export of live ocean clam

In 2006, the relatives of Íslensk kúffisk ehf. Þórshöfn is exploring the possibilities of fishing and processing live shellfish for the European market, but in many parts of central and southern Europe there are good markets for live sandwich shells. As this was a completely new product, it was clear that this required the development of fishing, processing, transport and marketing, which was different from what has previously been known in the utilization of the kúfi stock in Iceland. Extensive research work had to be done before it could be marketed as a finished product. Much work was put into the development of fishing, processing, storage, transport and promotion of the shell to potential buyers. It can be said that the results of this work have generally been very good and it has now become possible to find solutions to most of the challenges that were started with in the beginning. A live kúfskell is ready as a complete product. It fully compares with other live sandwich shells sold in the central and southern European markets in terms of quality, wholesomeness and delivery security. However, sales of the product have been stagnant. Despite the fact that during the entire project period, distributors, chefs, restaurant owners, retailers and general consumers in important market areas were very well received in important market areas, it has not yet been possible to win the market that was initially aimed at. The main reason for the sluggishness of sales is due to the conservative nature of live sandwich shells. They are simply not willing to try shells other than the ones they know. The promoters will, however, continue to work on marketing live scallops as they know that the product is fully competitive with other sandwich shells sold in the European market.

In 2006 the owners of Íslenskur kúffiskur ehf. in Þórshöfn began to explore the possibilities of catching, processing and exporting live ocean clam from Iceland for the European market, where there is a strong demand for live bivalves. Ocean clam is traditionally not a part of the bivalve species that have been sold alive at these markets in the past, which meant that considerable research and development work had to be done regarding the whole value chain of the clam before it could be ready as a marketable product. The main emphasis of the R&D work was on catching, processing, storage, transportation and marketing. After having worked on solving various challenges in the value chain of the ocean clam for over three years the overall results look promising, as solutions have been developed for most of the tasks that had been defined in the beginning. Live ocean clam is now ready as a final product that is compatible with other bivalves sold in central and southern Europe regarding quality, food safety and delivery reliability. The target markets have however not accepted the product with the same enthusiasm as originally hoped for. The target markets seem to be more conservative than expected when it comes to trying out new alternatives. The outcome of the project is that challenges regarding catching, processing, storing and transportation of live ocean clam have been solved. The final product is therefore ready, but unfortunately the market has not accepted it as hoped for. The project participants will though continue to look for promising markets and are convinced that live ocean clam will become a valuable export product for the Icelandic seafood industry sometime in the future.

View report

Reports

Undesirable substances in seafood products - results from the Icelandic marine monitoring activities in the year 2009

Published:

01/11/2010

Authors:

Hrönn Ólína Jörundsdóttir, Natasa Desnica, Þuríður Ragnarsdóttir, Helga Gunnlaugsdóttir

Supported by:

Ministry of Fisheries and Agriculture

Contact

Natasa Desnica

Research Group Leader

natasa@matis.is

Undesirable substances in seafood products - results from the Icelandic marine monitoring activities in the year 2009

In 2003, at the initiative of the Ministry of Fisheries, monitoring of undesirable substances in marine products, both for human consumption and products for the fish oil and flour industry, began. The purpose of the monitoring is to assess the condition of Icelandic marine products with regard to the amount of contaminants. The aim is also to collect independent scientific data on undesirable substances in marine products for the government, the fishing industry as well as buyers and consumers of Icelandic seafood. The data collected in the monitoring project will also be used in risk assessment and to build up a database on contaminants in the Icelandic ecosystem. Coverage of contaminants in marine products, both in the mainstream media and in scientific journals, has many times demanded the response of the Icelandic government. It is necessary to have scientific results available that demonstrate the actual condition of Icelandic seafood in order to prevent damage that may result from such coverage. Furthermore, the limits of contaminants are under constant review and it is important for Icelanders to participate in such a review and support their case with scientific data. This shows the importance of regular monitoring and that Iceland conducts independent research on such an important issue as marine product pollution. This report is a summary of the results of the monitoring for the year 2009. Assessment of the condition of Icelandic marine products with regard to contaminants is a long-term project and will only be carried out through continuous monitoring. Every year, therefore, the missing data is carefully reviewed, thus aiming to fill in the gaps. In 2009, the following substances were measured in marine products intended for human consumption as well as products for the fish oil and flour industry: dioxins, dioxin-like PCBs and pointer PCBs, PBDEs, metals, as well as 12 different types of pesticides. A special effort was made to measure PBDEs and metals in 2009 and very few of these substances were measured in Icelandic seafood. As before, a small amount of undesirable substances was generally measured in Icelandic seafood in 2009. Oil and flour made from blue whiting, however, have to be close to or above the permitted limits for certain substances.

This monitoring of undesirable substances in seafood products was initiated by the Icelandic Ministry of Fisheries and Agriculture in the year 2003. Until then, this type of monitoring had been limited in Iceland. The purpose of the project is to gather information and evaluate the status of Icelandic seafood products in terms of undesirable substances. Further, the aim of the project is to provide independent scientific data on undesirable substances in Icelandic seafood for food authorities, fisheries authorities, industry, markets and consumers. The information will also be utilized for a risk assessment and gathering of reference data. This report summarizes the results obtained in the year 2009 for the monitoring of various undesirable substances in the edible part of marine catches, fish meal and fish oil for feed. The monitoring began in 2003 and has now been carried out for six consecutive years. The evaluation of the status of the Icelandic seafood products in terms of undesirable substances is a long term project which can only be reached through continuous monitoring. For this reason, we carefully select which undesirable substances are measured in the various seafood samples each year with the aim to fill in the gaps in the available data. Thus the project fills in gaps of knowledge regarding the level of undesirable substances in economically important marine catches for Icelandic export. In the year 2009, data was collected on dioxins, dioxin-like PCBs, marker PCBs, 12 different types of pesticides, PBDEs and metals in the edible part of fish, fish oil and meal for feed. Samples collected in 2009 generally contained low concentrations of undesirable substances. These results are in agreement with our previous results obtained in the monitoring programs in the years 2003 to 2008. This year (2009) special emphasis was placed on gathering information on PBDE and metals. The results reveal that these compounds are in very low amounts in fish and fish products and most PAHs are below detection limits. Blue whiting meal and oil can contain undesirable substances in concentration close to or exceeding the maximum level set by the EU.

View report

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.

View report

Reports

Processing in line boats / Processing in line boats

Published:

01/10/2010

Authors:

Róbert Hafsteinsson, Albert Högnason, Sigurjón Arason

Supported by:

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 ohf, Brim hf, Samherji hf, Vísir hf, Hraðfrystihúsið Gunnvör hf 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 result of this report is: Design of a production process on board liner vessels, a result report. Experimental report on thawing of bait, saury, condoms and herring. And a preliminary draft for the design of an automatic train system on board a liner. The main results of the project are the following: Great optimization involves thawing the bait in so-called snail tanks, the thawing time will be reduced from 17 hours to about 2-3 hours. Instead of taking the bait out 17 hours earlier, it is fed directly into the thawing tank from the bait freezer. This method saves a lot of time. Experiments show that fish that are allowed to bleed for approx. 10-15 minutes during a large water change, are then gutted and then cooled down to zero degrees for approx. A special processing process was designed on board liners that addresses these quality stamps. A preliminary draft of an automatic train system on board future liner vessels was also designed. The purpose of such a system is to have no train attendant on board the train, but to arrange and sort it on top of the working deck in the trolleys. The tub then goes into a specially designed tub lift, which was also designed for this project, onto the train and onto special train straps that move the tub to the relevant place on the train.

This project is a collaboration work between; Matis ohf, Brim hf, Samherji hf, Vísir hf, Hradfrystihusið Gunnvör hf 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. The projects payoff is; Design of processing line onboard line boats, payoff report. Experiment report on thawing of bait, Saury, Cuttle and Herring. Also preliminary design of automatic system for loading boxes from holds in line boats. The primary results from this report are as follows: A great increase in efficiency is by thawing the bait in so called screw tanks, the thawing time reduced from 17 hours (current thawing method) down to appr. 2 - 3 hours. Instead of taking the bait out of the freezer 17 hours before use, the screw tank is feed from the freezer simultaneously. Previous experiments show that when the fish is bleeded for appr. 10‐15 minutes, and then gutted and afterwards cooled down to zero degree on Celsius for approx. 20-25 minutes in a special screw tank filled with slush gives increased fish quality. A special processing trail was designed for lineboats which takes into account this quality.

View report

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.

View report

Reports

Pollution monitoring in the marine environment around Iceland 2008 and 2009 / Monitoring of the marine biosphere around Iceland 2008 and 2009

Published:

01/09/2010

Authors:

Hrönn Ólína Jörundsdóttir, Natasa Desnica, Sonja Huld Guðjónsdóttir, Þuríður Ragnarsdóttir, Helga Gunnlaugsdóttir

Supported by:

Ministry of the Environment and Ministry of Fisheries and Agriculture

Contact

Natasa Desnica

Research Group Leader

natasa@matis.is

Pollution monitoring in the marine environment around Iceland 2008 and 2009 / Monitoring of the marine biosphere around Iceland 2008 and 2009

This report presents the results of an annual monitoring project funded by the Ministry of the Environment and the Ministry of Fisheries and Agriculture. The purpose of this monitoring is to fulfill Iceland's obligations regarding the Oslo and Paris Agreement (OSPAR), as well as the AMAP (Artic Monitoring Assessment Program). The data has been sent to the International Council for the Exploration of the Sea (ICES) database. The Marine Research Institute collects samples and Matís oversees the preparation of samples and measurements of trace elements in the marine environment. The samples are measured at Matís and at the Laboratory of Pharmacology and Toxicology. Various inorganic trace elements and chloro-organic substances were measured in cod caught in Hafró's annual spring rally in March 2009 and in mussels collected at 11 locations around the country in August / September 2008. Monitoring in the marine environment around Iceland began in 1989 and data is collected in database. The report provides overview images for some of the topics covered. Cadmium is regionally higher in Icelandic mussels compared to mussels from other countries. There are small changes between years in the concentration of inorganic and organic substances, but a detailed statistical analysis of the data is needed in order to be able to assess with scientific methods the increase or decrease of pollutants in the marine environment in Iceland.

This report contains results of the annual monitoring of the biosphere around Iceland in 2008 and 2009. The project, overseen by the Environmental and Food Agency of Iceland, is to fulfill the OSPAR (Oslo and Paris agreement) and AMAP (Arctic Monitoring Assessment Program) agreements. The project was funded by the Ministry of the Environment and the Ministry of Fisheries and Agriculture. The data has been submitted to the ICES databank (ices.dk), collection of data began in 1989. Matís ohf is the coordinator for marine biota monitoring and is responsible for methods relating to sampling, preparation and analysis of samples. The samples were analyzed at Matís and at the Department of Pharmacology and Toxicology at the University of Iceland. Trace metals and organochlorines were analyzed in cod (Gadus morhua) caught in March 2009 and in blue mussel (Mytilus edulis) collected in August / Sept 2008. Marine monitoring began in Iceland 1989. Cadmium is higher in some locations in Iceland compared to other countries . No significant changes were observed in the concentration of organic or inorganic pollutants investigated. However, a thorough statistical evaluation has to be carried out on the available data to analyze spatial and temporal trends of pollutants in the Icelandic marine biosphere.

View report

Reports

Let's look at the yellow from fishing in the stomach - a study of factors that affect the value of cod / Factors influencing the quality and value of the Icelandic cod; a value chain perspective

Published:

01/09/2010

Authors:

Helga Gunnlaugsdóttir, Jónas R. Viðarsson, Ásta M. Ásmundsdóttir, Cecilia Garate, Hrönn Jörundsdóttir, Ingibjörg G. Jónsdóttir, Sigurjón Arason, Vordís Baldursdóttir, Þorsteinn Sigurðsson, Sveinn Margeirsson

Supported by:

Increased value of seafood (AVS), HB ‐ Grandi, Guðmundur Runólfsson hf, Fiskistofa, Hafrannsóknastofnunin, Matís

Let's look at the yellow from fishing in the stomach - a study of factors that affect the value of cod / Factors influencing the quality and value of the Icelandic cod; a value chain perspective

The aim of this project was to gather more detailed information than has previously been done on the chemical composition, processing properties and value of cod in the value chain. The main results of the study are:

• There was not much difference in the carcass of cod by season, but the carcass coefficient was slightly higher in December than around the spawning season (February-May) when it was lowest. No association was found between fish body and liver fat content.

• There was a positive relationship between hepatic index and liver fat content (R2 = 0.55). However, the relationship was not linear, but the fat content increased rapidly at a low liver factor but less as the liver factor increased. Likewise, the fat content of the liver increased with length and age in both hens and females.

Liver fat content, fish weight or body mass index do not provide conclusive evidence of fillet utilization. Likewise, the water content and water resistance of the fillets had little or no effect on production efficiency or emissions.

• The summary result of the assessment of the effect of sex, sexual maturity and age on fillet utilization is that there is a difference in fillet utilization between individual fishing trips, this difference seems to be somewhat dependent on the maturity of the fish and is according to available data lowest at maturity stage 4 (ie fish in spawning or spawning). It should be noted, however, that there is a considerable imbalance in the database regarding the distribution of puberty in individual fishing trips and there are relatively few samples of fish from stages 3 and 4 compared to stages 1 and 2.

A comparison was made of the concentration of PCB7 in cod directly from the sea on the one hand and after processing, ie in frozen fillets, on the other. There was no significant difference in the concentration of PCB7 in whole fish and frozen cod fillets, so fish processing does not seem to affect the concentration of these substances in the fillets.

• There was no statistically significant relationship between iron concentration (Fe), selenium (Se), lead (Pb) or PCB7 and gender, age or puberty. There is a statistically significant relationship between the concentration of mercury in the flesh of cod (ie in fillets) and age, length and sexual maturity. Mercury is known to accumulate in the flesh of fish with age and the results of this study are consistent with and based on these results.

The aim of this project is to collect more detailed data about the factors influencing the quality and value of the Icelandic cod during processing, were the end product is frozen fillet. Data were collected from 2007 to 2008 on fillet yield, water content, water capacity, gaping, parasites as well as the chemical composition (nutrients & undesirable substances). These variables are important for the quality and profitability of the cod industry. Emphasis has been laid on connecting these variables to data about fishing ground, season of fishing, sex, sexual maturity in order to increase our understanding on how it is possible to maximize the value of the catch. In addition, the liver from each individual cod was collected and the fat and water content analyzed. The results from this study show that there is a nonlinear relationship (R2 = 0,55) between the liver condition index and the fat content of the liver.

View report

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.

View report

Reports

The effect of different cooling techniques on the quality changes and shelf life of whole cod (Gadus morhua)

Published:

01/08/2010

Authors:

Hannes Magnússon, Kolbrún Sveinsdóttir, Lárus Þorvaldsson, María Guðjónsdóttir, Hélène L. Lauzon, Eyjólfur Reynisson, Árni R. Rúnarsson, Sveinn H. Magnússon, Jónas R. Viðarsson, Sigurjón Arason, Emilia Martinsdóttir

Supported by:

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

Contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

The effect of different cooling techniques on the quality changes and shelf life of whole cod (Gadus morhua)

The purpose of the experiment was to investigate the effect of three different cooling methods on the shelf life of whole, gutted cod: (i) Cooling with crushed plate ice, (ii) cooling with liquid ice, (iii) pre-cooling with liquid ice and then cooling with crushed plate ice. Temperature processes were monitored with temperature sensors in all groups during the storage period. Samples were assessed by sensory evaluation, microbial and chemical measurements during the 10 days the fish was stored. The results of microbial and chemical measurements were generally in good agreement with the results of sensory evaluation. Comparison of experimental groups revealed that cod chilled with liquid ice had a shelf life of about two to three days shorter than the other two groups. The shelf life of the cod was considerably shorter than various previous studies have shown, especially in the group that was cooled with liquid ice (only 9-10 days). It is now clear that the cod that was cooled with liquid ice was vanished on board the fishing vessel compared to the other two groups. In addition, refrigerated storage after landing was not as good as might be considered, but the temperature fluctuated between 2-5 ° C. This could possibly explain the shorter shelf life of all groups compared to previous studies.

The aim of this experiment was to investigate the effect of three different cooling methods on the storage quality of whole, bled gutted cod: (i) Cooled with crushed plate ice, (ii) cooled with liquid ice, (iii) pre-cooled in liquid ice and then cooled with crushed plate ice. The temperature history of each group was studied using temperature loggers. The samples were analyzed with sensory, microbiological and chemical methods for up to 10 days from catch. The results from microbial and chemical measurements were generally in good agreement with the results from sensory evaluation. Comparison of the groups showed that the use of liquid ice instead of plate ice resulted in two to three days shorter shelf life than in the other two groups. The shelf life in this study was considerably shorter compared to previous studies with whole cod, especially in the experimental group where liquid ice was used for cooling (only 9-10 days). It is now known that the liquid iced group in this experiment was insufficiently iced on board the fishing vessel compared to the other two groups. Additionally, the ambient temperature in the cold room of the fish plant was relatively high and fluctuated between 2 - 5 ° C during the storage period. This could possibly explain the shorter shelf life of all groups compared to some earlier studies.

View report

Reports

Effect of improved design of wholesale EPS fish boxes on thermal insulation and storage life of cod loins - simulation of air and sea transport

Published:

01/08/2010

Authors:

Björn Margeirsson, Hélène L. Lauzon, Kolbrún Sveinsdóttir, Eyjólfur Reynisson, Hannes Magnússon, Sigurjón Arason, Emilía Martinsdóttir

Supported by:

EU (contract FP6-016333-2) Chill-on, AVS Fund of Ministry of Fisheries in Iceland (project no. R037-08), Technology Development Fund of the Icelandic Center for Research (project. No. 081304508), University of Iceland Research Fund

Contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

Effect of improved design of wholesale EPS fish boxes on thermal insulation and storage life of cod loins - simulation of air and sea transport

The aim of the experiments was to investigate how well two types of foam boxes protect cod neck pieces from the typical heat load in an air transport chain from a producer in northern Iceland to a buyer in Europe. Temperature measurements, sensory evaluation, chemical and microbial measurements were used to compare the foam boxes and examine the importance of the location of fillet pieces within the box (corner and center). Finally, the shelf life of neck pieces subjected to typical air transport temperature load was compared to the shelf life of neck pieces with stable -1 ° C storage, which is a viable option for container transport by ship. The new foam box, designed with the FLUENT heat transfer model, proved to be better than the older box in terms of thermal insulation. The temperature load on the first day of the experiment caused the highest product temperature in the corners to rise to 5.4 ° C in the older model but only to 4.5 ° C in the new model. The difference between the highest product temperature in the middle and the corners of the box was about 2 to 3 ° C. Sensory evaluation showed that storage in the new foam box led to a two to three day longer freshness period and one to two days longer shelf life with regard to storage in the older foam box. However, the differences between the boxes were not confirmed by chemical and microbial measurements. Position within the box (angle and center) did not significantly affect sensory evaluation results and there was only a small difference between placements in TVB-N and TMA measurements. Simulation of air and sea transport (temperature fluctuations and constant temperature) revealed that for well-cooled cod necks, one can expect one to five days longer freshness period and about three to five days longer shelf life in well-controlled sea transport compared to a typical air transport process from the North. As sea transport from Iceland often takes about four to five days longer than air transport (depending on, among other things, the day of the week and the location of the processing), this shows that sea transport is a viable option for Icelandic fresh fish producers. With the use of the new foam boxes in air transport, however, the fish will have a longer freshness period when it comes into the hands of buyers abroad than in shipping.

2nd edition, March 2011

In the previous version of the report, it was not considered clear enough that the environmental temperature trajectory that was to be simulated by sea transport was in fact based on more or less the best possible conditions in the sea transport chains of fresh fish products from Iceland. Temperature measurements in the cooling projects The simulation of cooling processes and Chill-on have shown that domestic transport is often accompanied by an undesirable temperature load for several hours. whether it is air or sea transport chains. This heat load was taken into account in the case of the airline chain and not the maritime transport chain in the first edition of the report. Most emphasis was on the length of shelf life in the previous edition of the report, but a discussion on the period of freshness is added in its new edition.

The aim of the study was to investigate the performance of two different types of EPS boxes in protecting pre-chilled, fresh fish products subject to temperature conditions, which are likely to occur during air- and land based, multimodal transport from a processor in North -Iceland to a wholesaler in Europe. The performance of the EPS boxes was evaluated by means of temperature monitoring, chemical- and microbial measurements and finally sensory evaluation. Furthermore, effect of fillet positions inside the wholesale fish packages (corner vs. middle) were investigated by means of the aforementioned methods. Finally, the shelf life of the air-transported simulation fish loins was compared to the shelf life of fish loins stored at around -1 ° C, which can be achieved during non-interrupted and well temperature-controlled, containerized sea transport. The new box, designed with a numerical FLUENT heat transfer model, proved to be better with regard to thermal insulation than the old box. The thermal load during the first day of the experiment caused the maximum product temperatures in the bottom corners of the top and second top to rise to 5.4 ° C and 4.5 ° C for the original and new boxes, respectively. The maximum temperature in the middle of the boxes was around 2 to 3 ° C lower than the maximum temperature in the bottom corners. According to sensory evaluation, storage in the new boxes resulted in approximately two to three days longer freshness period and one to two days longer shelf life than storage in the old boxes. The difference between the two box types is not as clear with regard to chemical and microbial measurements.

The sampling location (corner versus middle), did not significantly affect the sensory quality and only minor differences were noticed in TVB-N and TMA between sampling locations in the new box. Comparing the steady and dynamic storage in the old boxes it can be concluded that the increased freshness period (around 1-5 days) and shelf life (around 3-5 days) at steady temperature could compensate for the longer transport time by sea instead of air freight. This makes containerized sea transport a worthy choice for Icelandic fresh fish manufacturers depending on the week day and location of processing. However, for maximum remaining freshness period at the time of delivery to the buyer in Europe the results showed that air transport with the new boxes is the more advantageous transport mode relying on shorter transport time and improved thermal protection of the new boxes.

View report
EN
IS EN