Tag: Damaged bacteria

Reports

Comparison of transport modes and packaging methods for fresh fish products - storage life study and life cycle assessment

Published:

01/10/2012

Authors:

Björn Margeirsson, Birgir Örn Smárason, Gunnar Þórðarson, Aðalheiður Ólafsdóttir, Eyjólfur Reynisson, Óðinn Gestsson, Emilía Martinsdóttir, Sigurjón Arason

Supported by:

AtVest (Atvinnuþróunarfélag Vestfjarði)

Contact

Birgir Örn Smárason

Research Group Leader

birgir@matis.is

Comparison of transport modes and packaging methods for fresh fish products - storage life study and life cycle assessment

There is a great benefit in improved control of the value chain of exports of fresh fish knuckles for distribution in retail chains in the UK. Improved packaging methods could increase the shelf life of a product, which is fundamental to this business. With an airtight container, it would be possible to transport the product in a sludge tank with a low temperature (down to -1 ° C), which would both reduce the transport cost significantly and could also extend the shelf life of the product. The method also provides the option of packaging with consumer information, which makes further packaging abroad unnecessary. In air transport, it would be possible to pack all goods in a 12 kg foam box instead of 3 kg, as is most common today, thus saving significant transport costs. Temperature measurements, sensory evaluation, chemical and microbial measurements and life cycle analysis were used to compare different packaging solutions for sea and air transport. Fresh haddock pieces in vacuum-packed containers in a container with slush ice, which were stored at a typical temperature in container transport, turned out to have a shelf life of 3-4 days longer than the other experimental groups, probably mainly due to better temperature control. Consistency between the results of sensory evaluation and microbiological measurements was generally good. The lowest environmental impact of all groups was the pot group with sea-transported, vacuum-packed packaging, but this design could be further improved with regard to the mixing of the ice scraper and fish temperature control and thus the shelf life.

The aim of the project was to compare alternative packaging methods of fresh fish loins to the traditional packaging. Comparison was made between packages in terms of temperature control and product storage life by simulating air and sea transport from Iceland to UK in air climate chambers. The evaluation was made by the sensory panel and microbialand chemical analysis by the Matís laboratory in Reykjavík. Furthermore, the environmental impact of the aforementioned transport modes and packaging methods was assessed by means of LCA (Life Cycle Assessment). About 70–75% of Iceland's exports of fresh fillets and loins are transported by air and the rest by container ships. Increased knowledge on the advantages and disadvantages of the packages used for this fresh fish export will facilitate the selection of packages and improve the quality and storage life of the products. By using vacuum-packaging it is possible to use 12 kg packages in air freight instead of the traditional 3– 5 kg packages; but the market is increasingly demanding smaller individual packages. Sea transported larger packages use less space in shipping, lowering freight cost and environmental impact. Vacuum packed haddock loins immersed in slurry ice in a fish tub stored at sea transport temperature conditions proved to have a 3–4 day longer storage life than all the other experimental groups, probably mainly because of better temperature control. Good agreement was obtained between the sensory- and microbial evaluation. Finally, the sea transport-tub-group was found to be the most environmentally friendly and could be improved with regard to product temperature control and thereby storage life.

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Reports

Effect of superchilled processing of whole whitefish - pre ‐ rigor / Effect of supercooling on spoilage processes and shelf life of whole fish and fillets

Published:

01/05/2012

Authors:

Aðalheiður Ólafsdóttir, Björn Margeirsson, Kolbrún Sveinsdóttir, Sigurjón Arason, Eyjólfur Reynisson, Emilía Martinsdóttir

Supported by:

AVS Fund of Ministry of Fisheries in Iceland (R 062‐11)

Contact

Aðalheiður Ólafsdóttir

Sensory evaluation manager

adalheiduro@matis.is

Effect of superchilled processing of whole whitefish - pre ‐ rigor / Effect of supercooling on spoilage processes and shelf life of whole fish and fillets

The aim of the experiment was to investigate the effect of supercooling on the damage processes and shelf life of whole fish and fillets. A study was carried out on whole supercooled cod soon after fishing and also on the effect of supercooling on fillets made from supercooled cod and cod cooled in ice in the traditional way. Temperature measurements, sensory evaluation, chemical and microbial measurements were used to compare the following experimental groups, which were stored at –1.4 to –1.2 ° C average temperature:

1) NC: whole cod cooled in ice

2) SC: supercooled whole cod

3) NC-NC: traditional fillet processing from whole cod cooled in ice

4) NC ‐ SC: super-chilled fillets made from whole cod cooled in ice

5) SC-NC: traditional fillet processing from super-chilled whole cod

6) SC-SC: super-chilled fillets made from super-chilled whole cod

Sensory evaluation results suggest that supercooled processing of whole cod can extend its shelf life by two days. Supercooling of whole cod did not affect the acidity, water content, water resistance and microbial growth of whole fish compared to fish that were not supercooled during processing. According to sensory evaluation, there was little difference in the shelf life of different fillet groups. Shelf life was estimated at 16-18 days, which is quite a long time for cod fillets. However, the freshness period of the experimental group SC-SC seemed to be somewhat longer than the other groups. As with whole cod, there was little difference between the fillet groups in terms of microbial growth, chemical and physical properties. Limited differences between experimental groups can possibly be explained by stable and supercooled storage conditions. With this in mind, it is planned to carry out another similar experiment, which will simulate more typical environmental temperature processes in the transport of fresh fish products (0–4 ° C) than in this experiment (–1.4 to –1.2 ° C).

The main aim of the study was to study the effects of superchilled processing on storage life of both whole fish and fillets. The following experimental groups were evaluated by means of temperature monitoring, chemical and microbial measurements and sensory evaluation, which were stored at mean temperatures of –1.4 to –1.2 ° C:

1) NC: non ‐ superchilled whole cod

2) SC: superchilled whole cod

3) NC ‐ NC: non ‐ superchilled fillets from non ‐ superchilled whole cod

4) NC ‐ SC: superchilled fillets from non ‐ superchilled whole cod

5) SC ‐ NC: non ‐ superchilled fillets from superchilled whole cod

6) SC ‐ SC: superchilled fillets from superchilled whole cod

The results from the sensory evaluation indicate that superchilled processing of whole cod can extend shelf life by two days. Differences in values of pH, water content, water holding capacity and bacterial growth between the superchilled and non ‐ superchilled whole fish groups were minor. Differences in sensory scores between the fillet groups were small. Shelf life was estimated between 16 and 18 days which is quite long shelf life for cod fillets. However, the SC ‐ SC group seemed to retain freshness a little longer than other groups. As in case of the whole cod, the differences in bacterial count, chemical and physical properties between the fillet groups were small. Very similar fish temperatures between both the whole fish and the fillets groups resulting from the superchilled storage conditions applied may be the main reason for the small differences obtained. Thus, another study with more common temperature conditions during transport and storage of fresh fish (chilled but not superchilled) will be performed.  

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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.

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Reports

The effect of cooling methods at processing and use of gel-packs on storage life of cod (Gadus morhua) loins - Effect of transport via air and sea on temperature control and retail-packaging on cod deterioration

Published:

01/05/2010

Authors:

Emilia Martinsdóttir, Hélène L. Lauzon, Björn Margeirsson, Kolbrún Sveinsdóttir, Lárus Þorvaldsson, Hannes Magnússon, Eyjólfur Reynisson, Arna Vigdís Jónsdóttir, Sigurjón Arason, Maria Eden

Supported by:

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

Contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

The effect of cooling methods at processing and use of gel-packs on storage life of cod (Gadus morhua) loins - Effect of transport via air and sea on temperature control and retail-packaging on cod deterioration

The purpose of the experiments was to investigate the effect of different cooling during processing and temperature fluctuations in transport with and without a cooling mat on the shelf life of cod necks. In processing, it was compared to use no pre-cooling for filleting, liquid cooling and skin cooling (CBC) which is always liquid-cooled. The effect of simulated temperature fluctuations in transport temperature changes (RTS) was compared with storage at a constant temperature (-1 ° C). The effects of using a cooling mat in storage and transport were also assessed. Samples were quality assessed by sensory evaluation, microbial and chemical measurements. Temperature was monitored with thermometers. Skimmed cod fillets in foam plastic boxes were transported to Bremerhaven by air and ship, where they were repackaged in air and aerated packages (MAP) and stored at 1 ° C. Chemical and microbiological measurements were performed to monitor quality changes. The temperature of the erythema necrosis was lower than in the first 2 days of the experiment. The cooling mats had a certain effect of lowering the temperature when temperature fluctuations were in the process and lower temperatures were maintained throughout the storage period. However, the use did not affect the duration of freshness or shelf life according to sensory evaluation. The number of microorganisms was somewhat lower if temperature fluctuations occurred in the process, but there was little difference at a constant temperature. Storage at a constant, low temperature (-1 ° C) prolonged shelf life by approx. 3 days according to sensory evaluation and it was in accordance with microbial counts and measurements of TVB-N and TMA. Experiments in Bremerhaven showed that the number of microorganisms was generally lower when using aerated packaging compared to airborne fish. This was especially noticeable in the flying fish. The fish transported by ship was still stored for as long as the fish transported by air. This is due to the fact that the flying fish experienced greater temperature fluctuations during transport and its surface temperature measured 4 ° C on arrival in Bremerhaven. The transport time by ship was much longer (+48 hours) but the surface temperature was below 2 ° C on receipt. The use of cooling mats had little effect on the temperature during transport, but nevertheless the surface temperature was slightly lower in fish with cooling mats on arrival in Bremerhaven both by air and by ship.

The main aim of the experiment was to investigate the effects of different cooling techniques during processing and temperature fluctuations during transport on the storage life of cod loins with and without gel packs. The following cooling techniques were studied: combined blast and contact (CBC) cooling (with liquid cooling prior to the CBC cooling), only liquid cooling and where no special cooling was used prior to deskinning and trimming. The effect of real temperature simulation (RTS) during storage was compared to a steady storage temperature of -1 ° C. The samples were analyzed with sensory, microbial and chemical methods. The temperature was monitored from packaging using temperature loggers. CBC cooled loins were transported to Bremerhaven via air and ship freight after packaging in EPS boxes. The fish was repacked in air and modified atmosphere and stored at 1 ° C. Deteriorative changes were evaluated by microbial and chemical indicators. CBC cooling resulted in a lower temperature profile the first two days of the experiment. The use of gel packs lowered somewhat the temperature increase in the products when RTS was applied and lower temperature was maintained during the entire storage period. According to sensory evaluation, the use of gel packs did not result in prolonged freshness period or shelf life. According to microbial and chemical analysis no marked difference was seen whether gel packs were used or not in groups stored at a steady temperature. However, microbial counts were somewhat lower and slower formation of TVB-N and TMA occurred in RTS groups where gel packs were used compared to no gel packs. Storage at a steady -1 ° C resulted in extended shelf life of three days according to sensory evaluation. This was confirmed by microbial and chemical analysis as lower microbial counts, TVB-N and TMA values were generally obtained in the steady temperature group than in the group receiving the RTS treatment. The storage studies carried out at Bremerhaven on modified atmosphere vs. air packed loins showed generally lower microbial counts, especially in the air transported fish. Deterioration process of air and sea freight fish was however similar. Re-packaging of sea freight fish at a later stage did not significantly affect its deteriorative process compared to re-packed air freight fish. This might be due to the fact, that the air freight fish was subject to high temperatures during transport and surface temperature reached over 4 ° C. The sea freight fish had a much longer transport phase, but arrived with surface temperatures below 2 ° C. This shows that not only the time of re-packaging but also the temperature profile during transport are important factors influencing the deteriorative process and shelf life. Gel packs did not have significant cooling effect in this experiment. However the surface temperature in boxes with a gel pack was slightly lower than in boxes without a gel pack independently of transport mode used.

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