Contact
Sæmundur Sveinsson
Research Group Leader
saemundurs@matis.is
This report is closed. / This report is closed.
Tag: Cod
Contact
Sigurjón Arason
Chief Engineer
sigurjon.arason@matis.is
The effects of insulated tub depth on the quality of iced Atlantic cod / Effect of insulated tub depth on the quality of frozen cod
The aim of the project was to investigate the quality of cod that had been gutted one day after fishing, frozen and packed in 12 different sized tanks, 4 × 250 L, 4 × 460 L and 4 × 660 L. Experimental fish were monitored at the top and bottom of each tank . The pots were stored in a temperature controlled environment at 1 ° C and measurements were made after 6, 10, 13 and 15 days after packing. To assess the quality of the cod, water loss was used in tanks after storage, processing utilization and sensory evaluation. The results showed that water loss was highest in 660 L pots and lowest in 250 L pots. There was no difference in processing efficiency. In all cases, there was less looseness in the bottom of the pot compared to the top, probably due to the different size of fish in the top and bottom. There was no difference in the results of the quality factor (QIM) evaluation between pots, but the existing sensory evaluation scales do not include the properties on which a clear difference was seen. There was a big difference between fish in the top layer and fish in the bottom layer in all cases, but ice vessels and marine fillets were more bulky on bottom fish. As a follow-up to the experiment, a new sensory evaluation scale will be designed in ongoing research on the quality of frozen and supercooled fish in different large tanks, which will address these factors, ie. let's go for ice cream and bruises in fillets.
The aim of this project was to examine the quality difference of Atlantic cod that had been iced and packed into 12 different sized food containers (tubs), 4 × 250 L, 4 × 460 L and 4 × 660 L. Each tub was split up into two groups, top-and bottom layer. Drip loss, processing yield, and sensory evaluation were used to evaluate the quality of the cod. The results showed that the greatest drip loss was in the 660 L tub, and the least in the 250 L tub. There was no difference in processing yield. Sensory evaluation showed no difference between tubs, except that the fillets from fish in the bottom layer of all containers had less gaping than fillets from the top layer of fish, most likely due to size differences of top-and bottom layer fish. No current sensory evaluation scales account for different amounts of ice marks and crushed fillets that was detected between fish in the top-and bottom layer of the tubs. The results of this project will be used in continuing research of iced and superchilled fish in different sized containers to develop a new sensory scale that will account for these qualities.
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Contact
Sigurjón Arason
Chief Engineer
sigurjon.arason@matis.is
Styrene migration from expanded polystyrene boxes into fresh cod and redfish at chilled and superchilled temperatures
The aim of the experiment was to investigate the possible flow of styrene from foam plastic boxes to fresh cod and redfish fillets, which are stored at typical temperatures during sea transport of fresh fillets from Iceland to Europe or America. US buyers want fish fillets to be packed in plastic bags before packing in a foam box due to possible styrene contamination from foam to fish. Therefore, in this project, styrene was measured in fish, which had been stored without plastic bags in foam boxes, and the amount of styrene was compared with the standards of the US Food and Drug Administration (FDA). A total of 12 foam boxes containing cod or redfish fillets were stored for 4, 7 or 13 days at either -1 ° C or 2 ° C, which corresponds to the optimal and highest probable temperature in fresh fillet shipping. One 10-50 g sample was taken from the lower part of the bottom fish fillet in each box and had thus been in direct contact with foam plastic and therefore placed in a glass bottle. Subsequently, the 12 samples were sent for analysis to Eurofins, an international laboratory in Germany. The results show that the amount of styrene, as well as other undesirable substances such as benzene and toluene, was below 0.01 mg / kg fish in all twelve fish samples. The FDA guideline (maximum) is 90 mg of styrene per kg of fish per person per day, which is equivalent to The result of this experiment is that a consumer has to consume 9000 kg of fish daily to meet the FDA standard, which is a very unrealistic amount. The main conclusion of this experiment is that it is not necessary to pack fresh fish fillets in plastic bags for packing in foam boxes, which are stored and transported in refrigerated and supercooled conditions.
The aim of the study was to investigate possible styrene migration from expanded polystyrene into fresh cod and redfish, two important export fish species in Iceland, while stored under conditions mimicking transport by ship from Iceland to America and Europe. American buyers wish to have a plastic bag between EPS boxes and fish during transport as a safety measure due to possible styrene migration. Thus, this project was conducted to investigate if adding a plastic bag is necessary with regards to safety limits for styrene migration from packaging to food set by the FDA (US Food and Drug Administration). A total of twelve samples of cod and redfish were stored in EPS boxes manufactured by Tempra ltd. for 4, 7 and 13 days at two temperatures (-1 ° C, 2 ° C) which represent optimal and expected maximum storage temperatures during sea transport of fresh fish. A sample of 10-50 grams of fish, which had been in direct contact with the packaging, was taken from the bottom of each box, as it is considered the most hazardous place regarding styrene migration, and put in a glass bottle before analysis. Finally, the twelve samples of fish were sent to Eurofins, an international laboratory in Germany, for analysis. The results show that styrene content, and other solvent residues like benzene or toluene, were below 0.01 mg / kg in all twelve samples of fish. The FDA's daily intake limit of styrene is 90 mg / kg per person per day, which means that in this study an unrealistic intake of at least 9000 kg of fish would be necessary to exceed this FDA´s limit. The main conclusion from this study is therefore that a plastic bag is not needed to safely pack cod and redfish fillets into EPS boxes to be stored under chilled and superchilled temperatures.
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Contact
Sigurjón Arason
Chief Engineer
sigurjon.arason@matis.is
The effects of different packaging solutions on the shelf life of fresh cod loins - drainage holes, cooling media and plastic bags / The effect of different packaging solutions on the shelf life of fresh cod necks
Boys' clothes, refrigerants and plastic bags
The aim of the study was to investigate the effect of different foam plastic boxes (with and without boys), the amount of coolant and plastic bags compared to plastic film in boxes on the quality of fresh cod necks. The age of the raw material during processing was about two days. Five different experimental groups were prepared and stored at -1.7 ° C for five days and subsequently stored at 2 ° C for 9 days, or the remainder of the storage period. Sensory assessment (Torry freshness assessment) and drip / water loss during storage were assessed 1, 7, 9, 12 and 14 days after packing. The results indicated that a neck piece packed under plastic wrap in a foam box without a boy and with the smallest amount (250 g) of refrigerant in the box was damaged significantly faster compared to other experimental groups. The longest shelf life from packing (12 days) was measured for products that were packed in a foam plastic box without boys, but were in a plastic bag inside the box and with a larger amount (750 g) of refrigerant (ice) outside the plastic bag. The results underlined the importance of maintaining a low and constant temperature throughout the storage period.
The aim of the study was to explore the effects of different expanded polystyrene (EPS) boxes (with and without drainage holes), cooling media and plastic bags compared to plastic films inside the boxes on the shelf life of fresh cod loins. The fish was caught two days before processing. Five experimental groups were prepared and stored at around - 1.7 ° C for five days followed by subsequent storage at around 2 ° C for nine days. Sensory (Torry score) and drip loss evaluations were performed 1, 7, 9, 12 and 14 days post packaging. The results indicated that loins packed under a plastic film in EPS boxes (without drainage holes) and with the lowest amount (250 g) of cooling medium spoiled faster compared with the other experimental groups. The longest shelf life from packaging (12 days) was obtained for loins packed in EPS boxes inside a plastic bag and covered with a larger amount (750 g) of ice. Furthermore, the sensory results were in accordance with the temperature profiles of the experimental groups, stating the advantages of a low and stable storage temperature.
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Contact
Gunnar Þórðarson
Regional Manager
gunnar.thordarson@matis.is
Analysis of spoilage processes during fresh fish transport / Comparison of transport and packaging methods for fresh fish products – storage life study
The aim of the project "Best fresh fish transport" was to improve the handling of fresh fish products in container transport and thereby increase their shelf life and the possibility of further transport by sea from Iceland, but there are significant savings compared to transport by air. This report deals with the analysis of the damage processes that take place during the storage and transport of fresh fish products. A comparison was made of transport in foam plastic boxes and in ice scrapers in pots at different temperatures. Different embodiments of both packaging solutions were compared and assessment factors included temperature, total number of microorganisms, amount of damaged microorganisms, water resistance, amount of erratic base and sensory assessment properties. In general, there was relatively little difference between experimental groups during storage. Differences were found between groups in individual sensory evaluation factors, but this difference was not comparable between days and is therefore probably due to the interaction between heterogeneous raw material and too few evaluated samples. The freshness time of all groups was seven to eight days and the shelf life was about 10 days. The packaging solutions studied in the experiment, as well as the storage temperature, had little effect on the spoilage processes of the cod products. The variability was primarily due to the storage time.
The aim of the project "Optimisation of fresh fish transport" was to improve the handling of fresh fish products during sea freight and increase the shelf life and the possibility of further maritime transport from Iceland, involving significant savings relative to the air freight. The present report covers analysis of the deterioration processes occurring during storage and transportation of fresh whitefish products. Comparison was made between transportation in expanded polystyrene boxes and in slurry ice in tubs at different ambient temperatures. Different versions of both packaging solutions were compared with regard to temperature, total viable count, amount of spoilage bacteria, water holding capacity, total volatile nitrogen bases (TVB‐N) and sensory properties. There were in general relatively small differences between experimental groups during the storage period. Some difference was observed between groups with regard to few sensory attributes, but the difference was not comparable between days which was likely due to heterogeneous material and too small sampling size. The freshness period of all experimental groups was seven to eight days and the shelf life around 10 days. The packaging solutions explored in the present study, as well as storage temperature, had generally little effect on the deterioration processes occurring in the fresh cod product. The observed variation was primarily attributed to the storage time.
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Contact
Gunnar Þórðarson
Regional Manager
gunnar.thordarson@matis.is
Comparison of packing of fresh fish products in boxes and pots for export by ship / Packing of fresh fish products in boxes and tubs intended for sea transport
The aim of the study was to find the best and most cost-effective method of packing fresh fish products for shipping with a view to maximizing the shelf life of a product, which is one of the key factors in the marketing of fresh fish products. Experiments were carried out with the transport of fresh fish products in containers with ice scrapers and compared with the transport in foam plastic boxes with regard to temperature control, product quality and transport costs. Different product groups were compared that were packed in different packaging and stored at different storage temperatures. The purpose of these experiments was to simulate the environmental conditions during the transport of fresh fish products, with a view to evaluating the effect of pre-cooling before packaging and packaging methods on the shelf life of the products. The results clearly indicate that refrigeration of products before packaging as well as low and stable storage temperatures are among the most important factors that increase the shelf life of fresh fish products. Different packaging solutions also affected the shelf life of fresh fish products, although the effect was not as decisive as the effect of temperature. The results indicate an increased likelihood of longer shelf life if fresh fish products are packed in tanks with sub-chilled sludge compared to traditional packaging in a foam plastic box with ice. To estimate the amount of ice scraper required to maintain an acceptable temperature, a heat transfer model was developed. An economic analysis of different packaging and transport was carried out in the project and this work shows significant savings with the use of tanks for transporting fresh fish products in comparison with foam plastic boxes. Pots can replace a foam plastic box to a considerable extent and be a cost-effective option for some companies. The economic analysis showed that larger parties could take advantage of this method, as they can fill entire containers for export. But the method is no less useful for smaller processes, which do not have the capacity to make large investments in equipment to ensure adequate cooling for the packaging of products for export of fresh raw materials. The results are a good contribution to discussions about fresh fish products in foreign markets.
The goal of the study was to find the best and most efficient method of packaging fresh fish for sea transport with the aim of maximizing the storage life of the product, which is a key element in the marketing of fresh fish. Experiments were made with the transport of fresh fish in tubs with slurry ice and compared with transport in expanded polystyrene boxes with regard to temperature control, product quality and shipping cost. Different product groups were compared, using different temperature conditions and packing methods to find the best outcome for fresh fish quality and storage life. Experimental results clearly indicate that the pre ‐ cooling for packaging and low and stable storage temperature play a major factor to maximize storage life of fresh fish products. Different packaging solutions are also a factor, though the effect was not as dramatic as the effects of temperature. The results indicate an increased likelihood of extended shelf life if fresh fish is packed in a tub with a slurry ice compared to traditional packaging in expanded polystyrene boxes with ice. In order to estimate the necessary amount of slurry ice to maintain acceptable temperature, a thermal model was developed. Economic analysis of different packaging and transport was also carried out and the results showed substantial savings with the use of tubs for the transport of fresh fish products in comparison with the styrofoam boxes.
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Contact
Sigurjón Arason
Chief Engineer
sigurjon.arason@matis.is
Impact of season, bleeding methods and storage temperature on the quality and stability of frozen cod climbs
The main goal of the project was to increase utilization and at the same time knowledge of the stability of cod climbing in frost according to the season. With increased knowledge of the effects of the season, the quality of raw materials and storage conditions on the stability of the liver in frost, it is possible to ensure that raw materials for further processing are available all year round. This report discusses the effects of the season, bleeding methods and storage temperature on the quality and stability of frozen cod climbs. Evaluation factors included enzymatic activity (free fatty acids) and evolution (primary and secondary subjects' evolution). Seasonality had a significant effect on the chemical composition and enzyme activity of the liver. This was reflected in higher fat content and higher levels of free fatty acids in the liver collected in July compared to liver from April. Frost stability also varied with the time of year as the liver from July was more susceptible to peroxide formation. Different bleeding methods (bleeding and gutting in one go (one step) and bleeding first and then gutting (two steps)) generally had little effect on the chemical composition and enzymatic activity of the liver. The haemorrhage methods, on the other hand, had a significant effect on the formation of a second-stage imagery of frostbite during storage, as the liver from fish bled in 2 steps was less craving compared to the liver from fish bled in one step. Storage temperature and time had a decisive effect on the stability of the livers in frost. Based on the available results, it is recommended to store frozen liver at -25 ° C rather than -18 ° C in order to slow down the damage process.
To our knowledge, there is limited information available regarding the effects of temperature, bleeding method, and seasonal variation on oxidation stability of cod liver during frozen storage. A profound knowledge of cod liver stability during frozen storage is needed to secure the available supply of cod liver for processing all year around. The objective of the present study was therefore to evaluate lipid deterioration during frozen storage of cod liver. The effects of temperature, storage time, bleeding method, and seasonal variation on lipid hydrolysis and oxidation were analyzed. Time of year significantly affected the chemical composition and enzymatic activity of the liver, which was reflected in a higher fat content and higher level of free fatty acids in the liver collected in July compared to liver collected in April. Stability during frozen storage also varied with season where liver from July was more vulnerable towards peroxidation. Different bleeding methods (bleeding and gutting in one step compared to bleeding first and then gutting (two steps)) had significant effect on the lipid oxidation where liver from fish bled in one step turned out to be more rancid compared to liver from fish bled in two steps. Storage temperature and time proved to be important factors with regard to lipid degradation of cod liver during frozen storage. Based on present results, in can be recommended to store frozen liver at - 25 ° C rather than -18 ° C in order to slow down these damage reactions.
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Contact
Sigurjón Arason
Chief Engineer
sigurjon.arason@matis.is
Effects of bleeding methods on the quality and storage life of cod and saithe products
The aim of the project was to examine the effect of different bleeding methods on the quality and shelf life of different cod and saithe products. By identifying ideal conditions for bleeding, gutting and bleeding, it is possible to prevent product defects due to blood and at the same time increase the stability of the products in transport and storage. The fish were either bloodied in the hands and in the machine. Bleeding took place in slush or sea and the effects of different bleeding times were examined. The effect of waiting time on tires before bleeding was also assessed, as well as bleeding and gutting the fish in one step or two steps (gutting performed after bleeding). The products studied in this project were chilled and frozen cod and saithe products, as well as salted cod products. Of the variables studied in this project, their importance differed in terms of which fish species were involved and what the final product was. When comparing comparable sample groups of cod and saithe, it is seen that different conditions are suitable for each species. This supports the theory that it is probably not possible to transfer the best bleeding method of cod to saithe and vice versa. Bleeding time and type of bleeding agent (sludge vs. seawater) had a decisive effect on the stability of the cod and saithe products examined. Cod products, both chilled and frozen, from raw material soaked in sludge generally resulted in improved quality and stability compared to if soaked in seawater. In contrast to cod, the bleeding of saithe into the sea generally resulted in a stable end product. The way the fish were bled and gutted also had a decisive effect on the final products. In the case of frozen cod products, raw and gutted raw material in one step generally yielded a more stable product compared to raw material that was gutted after bleeding had occurred (two steps). Salted products, on the other hand, were much more stable in storage if the raw material was gutted after bleeding. Different results were also obtained for saithe depending on the final product involved. Bleeding and gutting of saithe in a machine had a positive effect on the shelf life of chilled products compared to if made by hand. Machine bleeding and gutting, on the other hand, resulted in a much more unstable product in the cold. The results of the project show that the effects of different bleeding methods are quite dependent on the raw material as well as the final product involved.
The main objective of the project was to study the effects of different bleeding methods on quality and storage life of various cod and saithe products. Products defects due to blood residues can be prevented by optimizing bleeding protocols, and hence increase the quality and storage life of the products. For this, fishes were either bled and gutted by hand or by machine. The bleeding (blood draining) was carried out with seawater or slurry ice, and the effects of different bleeding times in the tanks were also investigated. Moreover, the effects of waiting time (on deck) before bleeding, as well as the procedure of bleeding technique (bleeding and gutting in one procedure vs. gutting after blood draining) were investigated. The various products evaluated were chilled and frozen cod and saithe products, and salted cod products. The importance of the different parameters investigated in this project varied considerably with regard to fish species and the final products. Comparison of parallel treatments groups of cod and saithe demonstrated that optimum bleeding procedures are different for each species. Waiting time on deck and bleeding media (slurry ice vs. seawater) significantly affected the storage life of the cod and saithe products. Cod products, both chilled and frozen, from fish bled in slurry ice generally resulted in improved quality and storage life compared to fish bled in seawater. In contrast to cod, bleeding or saithe in seawater resulted however in more stable products. The procedure during bleeding and gutting also had great impact on the storage life of the various products studied. Shorter storage life of salted cod products was generally observed when the raw material was bled and gutted in one step compared to when gutting was performed after bleeding (two steps). Rather conflicting results were, however, observed for saithe and were depending on the type of final product. Bleeding and gutting of saithe by machine improved the storage life of chilled products compared to when the saithe was bled and gutted by hand. The machine procedure had, however, negative effects on the storage life of the frozen saithe products. Overall, the results of this project indicate that the effects of different bleeding methods are highly relative to fish species as well as the final product of interest.
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Aðalheiður Ólafsdóttir
Sensory evaluation manager
adalheiduro@matis.is
Comparison of packaging methods for bulk storage of fresh cod loins / Comparison of packaging solutions in foam packaging for storage of cod products
The main objective of the experiment was to compare packaging solutions for fish in terms of quality deterioration and product temperature during storage, which is similar to the conditions for export and distribution. The objectives were to compare cold storage of products packed (1) in 5-kg units in (H1) ship or (H2) air boxes; (2) in 3 ‐ kg units in (H3) airbags compared to H2; (3) with CO2 mats (H4) to reduce microbial growth in 5 kg units stored under 93% vacuum in EPS boxes. The results show that the lifespan of H1 was shorter, but there were smaller quality changes among the other groups. However, the freshness was longest and the lifespan of H4, which compares with slower TVB-N and TMA formation and microbial growth due to CO2 formation as well as lower product temperature. The fastest microbial growth was measured in H3 after 8 days of storage. There was no significant difference between the groups in terms of TVB-N and TMA values, which were highest in H1 and H3. Drip was at least half as high in H4 as in other groups.
The overall aim of the storage study was to compare the quality deterioration and temperature profile of cod loins differently packaged in expanded polystyrene boxes and stored under conditions mimicking distribution. The purpose of the study was threefold; to compare chilled storage (1) or 5 ‐ kg bulk fish packaged in sea freight (H1) or air freight (H2) boxes; (2) of 3 ‐ kg (H3) or 5 ‐ kg (H2) bulk fish packaged in air freight boxes; (3) with the use of CO2 ‐ emitting pads (H4) as a mean to slow down bacterial deterioration of cod loins (5 kg) packaged under partial vacuum and stored in EPS boxes. The results clearly indicated that group H1 had a shorter shelf life as it developed spoilage characteristics faster than the other three groups. Less difference was seen between the remaining three groups but group H4 retained its freshness slightly longer than groups H2 and H3. This can be explained by the CO2 present and the lower mean product temperature. More advanced microbial spoilage was detected in H3 group compared to H2, as shown by higher microbial counts in H3 being though insignificant. No significant differences were observed after 8 ‐ day storage in TVB ‐ N and TMA content of the four groups, despite the higher levels measured in H1 and H3. Drip loss was at least two times higher in H4 than the other groups.
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Pollution monitoring in the marine environment around Iceland 2011 and 2012 / Monitoring of the marine biosphere around Iceland 2011 and 2012
This report presents the results of an annual monitoring project funded by the Ministry of the Environment and Natural Resources, as well as the Ministry of Industry and Innovation. The purpose of this monitoring is to fulfill Iceland's obligations under the Oslo and Paris Agreements (OSPAR), as well as the AMAP (Arctic Monitoring Assessment Program). The data are part of Iceland's contribution 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 University of Iceland 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 2012 and in mussels collected at 11 locations around the country in August / September 2011. Monitoring in the marine environment around Iceland began in 1989 and samples are collected once a year. for a year and worked according to international sampling instructions. The data is collected in a database, the report provides overview images for some of the materials monitored. Cadmium is regionally higher in Icelandic mussels compared to mussels from other countries. The results show changes in the pattern of chlorine organic matter in mussels collected near Hvalstöðin in Hvalfjörður in September 2011. The concentration of chlorine organic substances increased in 2009 and 2010 but decreased in samples from 2011 and has become comparable to the concentration measured before 2009. The concentration of DDEs is however, it was higher than before 2009. There were no visible changes in the concentration of these substances at the mussel collection point at Hvammsvík in Hvalfjörður or at any other collection site around the country that was studied in 2011. It is important to monitor these changes in the pattern of chlorine organic matter in mussels. in the monitoring project in the coming years to see how they change. A detailed statistical analysis of the data is in progress, i.e. Scientific methods can be used to estimate 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 2011 and 2012. The project, overseen by the Environment 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 Natural Resources as well as the Ministry of Industries and Innovation. The data obtained is a part of Iceland's contribution to the ICES databank (ices.dk). The collection of data started 1989. Matís 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 the Department of Pharmacology and Toxicology at the University of Iceland. Trace metals and organochlorines were analyzed in cod (Gadus morhua) caught in March 2011 and in blue mussel (Mytilus edulis) collected from 11 sites in August / Sept 2011. Marine monitoring began in Iceland 1989 and the sampling is carried out according to standardized sampling guidelines. Changes were observed in the organochlorine concentration patterns in blue mussels collected year 2011 at the sampling site Hvalstod in Hvalfjordur. The concentration of organochlorines increased in the years 2009 and 2010 but decreased in the samples from 2011 and is in line with the concentration of organohalogens in mussels before 2009. No noteworthy increase in organochlorine concentrations was however observed in blue mussels obtained at Hvammsvík in Hvalfjordur nor any of the other sample sites studied year 2011. These results need to be followed up in the annual monitoring of the biosphere around Iceland next year to see if this change in contaminant concentration pattern continues. A thorough statistical evaluation is on ‐ going on all the available data from this monitoring program to analyze spatial and temporal trends of pollutants in the Icelandic marine biosphere.