Tag: Undercooling

Reports

Minimizing spoilage in lobster with enzyme inhibition and hypothermia / Minimizing spoilage in Nephrops in Iceland

Published:

01/09/2011

Authors:

Guðmundur Gunnarsson, Aðalheiður Ólafsdóttir, Heiða Pálmadóttir, Páll Steinþórsson, Vigfús Ásbjörnsson

Supported by:

AVS Fisheries Research Fund

Contact

Aðalheiður Ólafsdóttir

Sensory evaluation manager

adalheiduro@matis.is

Minimizing spoilage in lobster with enzyme inhibition and hypothermia / Minimizing spoilage in Nephrops in Iceland

The purpose of this project was to maximize the activity of enzyme inhibitors (hasenose) with high subcooling to reduce myocardial infarction in lobster off Iceland. The effect of enzyme inhibitors on the quality aspects of lobster was assessed. The activity of different refrigerants on board fishing vessels during lobster fishing. The product of the project is then a definition of a processing process for the lobster industry with the use of enzyme inhibitors and high subcooling.

The aim of this project was to maximize the effects of using food grade protein inhibitor (EDTA) with combination of effective ice / seawater cooling to minimize muscle spoilage in nephrops in Iceland. To analyze different effects on nephrops quality factors when using the food grade protein inhibitor (EDTA) and to measure the effects of using different cooling media. The end product of this project is a simple code of practice information for the lobster industry in Iceland on how to use the combination of the food grade protein inhibitor (EDTA) with different cooling media to get the most effects on reducing muscle spoilage in nephrops in Iceland.

Report closed until 01.09.2013

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Reports

Effect of cooling and packaging methods on the quality deterioration of redfish fillets

Published:

01/09/2011

Authors:

Hélène L. Lauzon, Aðalheiður Ólafsdóttir, Magnea G. Karlsdóttir, Eyjólfur Reynisson, Björn Margeirsson, Sigurjón Arason, Emilía Martinsdóttir

Supported by:

EU IP Chill ‐ on (contract FP6‐016333‐2)

Contact

Aðalheiður Ólafsdóttir

Sensory evaluation manager

adalheiduro@matis.is

Effect of cooling and packaging methods on the quality deterioration of redfish fillets

The aim of the experiment was to evaluate the effect of slush ice cooling after filleting and / or packing in vacuum packaging on the deterioration of the quality of fresh redfish fillets. The fillets were stored at -1 ° C for 6 days to simulate well-executed sea transport in foam plastic boxes and then at 2 ° C, as happens after delivery abroad and storage in retail. Product and ambient temperature were monitored from packaging and sensory evaluation, microbial and chemical measurements were performed. The fish was caught in the spring and processed 6 days after fishing. The results show that the quality of the raw material was not the best during packaging as the development process (PV and TBARS) was well underway. This probably explains why none of these refrigeration methods led to an increase in shelf life. It was also found that there was no benefit in cooling the fillets unprotected in slush ice as the microbial growth and formation of TVB-N and TMA in the fillets was faster with further storage. However, it seems preferable to refrigerate vacuum packed fillets in ice cream as this method has led to slower growth of pest microorganisms, lower TMA levels and a slower development process. Photobacterium phosphoreum is important in the process of damaging fresh redfish fillets, regardless of the packaging method.

The aim of this study was to evaluate the effect of slurry ice cooling in process (post ‐ filleting) and packaging method (+/‐ oxygen) on the quality deterioration of skinned redfish fillets during storage in expanded polystyrene boxes simulating well ‐ performed sea freight transportation (6 days at ‐1 ° C) followed by storage at the retailer (2 ° C). Also, to assess the use of vacuum ‐ packaging to protect the fillets from direct contact with the cooling medium (slurry ice) and to achieve superchilling following extended treatment. Temperature monitoring as well as sensory, chemical and microbial analyzes were performed. The fish was caught in the spring and processed 6 days post catch. The results show that quality of the fillets was not optimal at packaging, due to the detection of primary and secondary oxidation products. This may have been the reason why shelf life extension was not achieved by any of the methods evaluated. Further, there was no advantage of cooling the fillets unpacked since this method stimulated microbial growth and formation of basic amines. On the other hand, slurry ice cooling of vacuum ‐ packaged fillets led to a slower microbial development, the lowest TMA level and delayed autoxidation. Finally, the importance of Photobacterium phosphoreum in the spoilage process of redfish fillets, independently of the packaging method, was demonstrated.

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Reports

Effect of temperature control on the efficiency of modified atmosphere packaging of cod loins in bulk

Published:

01/06/2011

Authors:

Hélène L. Lauzon, Kolbrún Sveinsdóttir, Magnea G. Karlsdóttir, Eyjólfur Reynisson, Björn Margeirsson, Emilia Martinsdóttir

Supported by:

EU IP Chill ‐ on (contract FP6‐016333‐2)

Contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

Effect of temperature control on the efficiency of modified atmosphere packaging of cod loins in bulk

The aim of the experiment was to compare the freshness, quality and shelf life of sub-chilled (CBC) cod necks in air storage and in aerated packages (MAP) at controlled temperatures to simulate temperature fluctuations during transport and distribution in the European market. Changes in the composition of the gas in the packages were monitored and sensory assessments and microbial and chemical measurements were performed. The fish was caught in bottom trawls in the spring and processed three days after fishing. There was a two-day prolongation during the freshness period and one day for the shelf life of fish in aerated packages (2.7 kg in a tray) compared to air (3.1 kg) in foam plastic, despite a 0.5 ° C difference in the average temperature of the groups and the air group was stored at lower temperatures (‐0.3 ± 0.9 ° C). The greatest temperature fluctuations led to the greatest shortening of the freshness time in air-conditioned packages. Cod saddles stored subcooled at -1.1 ± 0.1 ° C had a shelf life of 13 days. The results of microbial counts and chemical measurements showed the importance of Photobacterium phosphoreum in the formation of TMA in the process of damaging cod necks during both air and air exchange packaging. MAP and subcooling slowed down and changed the damage process. MAP increased drip by 2% in the later stages of storage.

The aim of this study was to compare freshness, quality deterioration and shelf life of CBC (combined blast and contact) ‐treated cod loins packaged in bulk under different atmospheres (air or modified atmosphere, MA) and stored under different temperature profiles to mimic temperature changes during transport and distribution to European markets. Sensory, chemical, microbial and headspace gas composition analyzes were performed regularly. The fish was caught by trawler in the spring and processed 3 days post catch. Following simulation of current sea freight conditions and distribution to European markets, a 2 ‐ day and 1 ‐ day increase in freshness period and shelf life of MA ‐ packaged fish (2.7 kg in trays), respectively, was observed compared to air ‐ stored loins (3.1 kg in EPS boxes). This is despite a mean product temperature difference of 0.5 ° C between the products, being lower (‐0.3 ± 0.9 ° C) for air ‐ stored fish. Abusive conditions had the greatest impact on the reduction of the freshness period for MAP fish. Superchilled storage of MAP loins (‐1.1 ± 0.1 ° C) resulted in a 13 ‐ day shelf life. Evaluation of microbial and chemical indicators emphasized the importance of Photobacterium phosphoreum and TMA formation in the deterioration of cod loins stored in air or MA, while superchilled MAP storage delayed as well as modified the spoilage pattern. MAP increased drip loss by about 2% at late storage.

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Reports

Functionality testing of selected Chill ‐ on technologies during a transport ‐ simulation study of palletized cod boxes: qPCR for fish spoilage bacteria, SLP model and QMRA to evaluate pathogen growth in spiked cod

Published:

01/11/2010

Authors:

Hélène L. Lauzon, Björn Margeirsson, Kolbrún Sveinsdóttir, Eyjólfur Reynisson, María Guðjónsdóttir, Emilia Martinsdóttir (Matís); Radovan Gospavic, Nasimul Haque, Viktor Popov (WIT); Guðrún Ólafsdóttir, Tómas Hafliðason, Einir Guðlaugsson, Sigurður Bogason (UoI)

Supported by:

EU IP Chill ‐ on (contract FP6‐016333‐2)

Contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

Functionality testing of selected Chill ‐ on technologies during a transport ‐ simulation study of palletized cod boxes: qPCR for fish spoilage bacteria, SLP model and QMRA to evaluate pathogen growth in spiked cod

In this study, tests were carried out on technical solutions developed in the EU project Chill ‐ on, where a simulation experiment was set up to simulate the actual transport of fish from Iceland to Europe. The temperature fluctuations experienced by the fish were aimed at mimicking transport from Iceland to France by ship. Pallets of cod fillets in foam plastic boxes were transported to the Westman Islands by ship and back to Matís in Reykjavík. Samples from these pallets were then compared with control samples that had been stored in Matís' refrigerated conditions. Cod nuggets were also packed in consumer packs (trays) immediately after processing and then after 6 days and were stored in subcooled or refrigerated conditions. Microbial growth experiments were also performed in which Listeria monocytogenes, Escherichia coli and Salmonella Dublin were added to cod necks stored in foam boxes in conditions similar to the storage and transport processes during export. Temperature measurements, sensory evaluation, microbial and chemical measurements were used to present data to test and verify the QMRA / SLP models and quantification of Pseudomonas bacteria using qPCR technology.

The aim of the cod wet trials and the corresponding shelf life study was to include scenarios to test and demonstrate the functionality of some Chill ‐ on technologies in a simulated cod supply chain. Temperature fluctuations were induced according to the actual scenario in the supply chain of cod from Iceland to France via sea freight. The study included sample groups created at the point of processing after packaging in EPS boxes. The reference group was stored at Matís under superchilled conditions. Simulation trials for downward distribution were performed at Matís upon receipt of the pallets shipped to the Westman Isles from Reykjavik (Iceland ‐ Europe freight simulation) and compared with the reference group. Repackaging of loins in retail trays was performed on days 0 and 6 with storage under superchilled and chilled conditions, respectively. In addition, a pathogen challenge trial was performed by spiking loins (5 kg) with Listeria monocytogenes, Escherichia coli and Salmonella Dublin, followed by storage in EPS boxes under temperature conditions simulating export and distribution. Temperature recordings along with microbial, chemical and sensory analyzes from the groups evaluated provided necessary data to test and validate the QMRA / SLP models and the quantitative molecular (qPCR) method to estimate counts of pseudomonads.

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Reports

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

Published:

01/11/2010

Authors:

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

Supported by:

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

Contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

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

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

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

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Reports

Effects of subcooling on salt uptake by pickling cod neck pieces (Gadus morhua)

Published:

01/06/2008

Authors:

Ragnhildur Einarsdóttir, María Guðjónsdóttir, Sigurjón Arason

Supported by:

Rannís Research Fund

Contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Effects of subcooling on salt uptake by pickling cod neck pieces (Gadus morhua)

Salt uptake and shelf life of skinless and boneless cod fillets (Gadus morhua) were studied at different temperatures. Salt uptake was examined at 0.5 ° C, -2 ° C and 5 ° C. The results indicate that fish muscle absorbs salt faster at -2 ° C than 5 ° C and salt uptake occurs most rapidly in the first 5 minutes. When looking for a final salt concentration of 0.6%, 4% brine is most desirable. In the shelf life test, the temperature was 0 ° C on the one hand and - 2 ° C on the other. Shelf life of fillets stored at -2 ° C was found to have a shelf life of 3-4 days longer than those stored at 0 ° C. Enzyme activity, more specifically trypsin-like protease activity, was examined in supercooled fish muscles. Fish muscle with a salinity of 0.5% stored at -2 ° C was found to have higher activity than other groups. The study suggests that it would be interesting to look more closely at the interaction between treatment, temperature and enzymes.

The salt uptake during brining and shelf life of skinless and boneless cod loins (Gadus morhua) was investigated at different temperatures. The salt uptake was studied at 0.5 ° C, -2 ° C and 5 ° C. The results show that the salt uptake of the cod muscle is faster at -2 ° C than at 5 ° C and that the salt uptake is fastest during the first 5 minutes. When aiming for a salt concentration of 0.6% in the muscle during brining it is optimal to use a 4% salt brine. In the shelf life study, samples were stored at 0 ° C and -2 ° C. The cod loins stored at -2 ° C showed 3-4 days longer shelf life than samples stored at 0 ° C. Enzymatic activity, or trypsin like protease activity to be more precise was studied in the superchilled muscle. Cod muscle with 0.5% salt and stored at -2 ° C showed higher activity than other groups. The study shows that there is a need for further studies on the combined effects of processing and storage temperatures on enzymatic activity.

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