Reports

Increased quality and stability of frozen herring products

Published:

30/08/2019

Authors:

Magnea Karlsdóttir, Huong Thi Thu Dang, María Guðjónsdóttir, Ásbjörn Jónsson, Sigurjón Arason

Supported by:

AVS R&D Fund

contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Increased quality and stability of frozen herring products

Freezing and frozen storage has proven to be an effective method to preserve and prolong the storage life of seafood products. Production of frozen products provides all year around product availability although the catching is seasonal. There are several factors that can affect the quality and stability of frozen fish products, including the state of the raw material, processing methods and storage conditions.

The aim of the study was to explore how the physicochemical properties of frozen herring fillets are affected regarding the state of the raw material during processing as well as storage conditions. Atlantic herring was processed and frozen pre- and post-rigor and stored at stable (-25 ° C) and abused storage conditions. To investigate the storage stability and physical properties of the fillets, thawing drip, cooking yield and color were evaluated, as well as proximate composition, fatty acid composition, pH and lipid degradation of the light and the dark muscle.

The study demonstrated the importance of stable and controlled temperature during storage and transportation of frozen herring products. Processing and freezing pre-rigor, in combination with stable storage conditions, was shown to be beneficial in terms of preventing lipid oxidation, as well as reducing thawing loss and maintaining the cooking yield of the herring fillets.

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Reports

Increased quality and stability of frozen herring products

Published:

01/11/2018

Authors:

Magnea Karlsdóttir, Huong Thi Thu Dang, María Guðjónsdóttir, Sigurjón Arason, Ásbjörn Jónsson

Supported by:

AVS R&D Fund (R 069-14)

contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Increased quality and stability of frozen herring products

Freezing and cold storage is an effective method of maintaining quality and extending the shelf life of seafood. The production of frozen products equals the supply of products where fishing is seasonal. There are many factors that can affect the quality and stability of frozen products. These include the condition of the raw material, processing methods and conditions for storage and transport, to name but a few. The aim of the study was to investigate the changes that take place in the chemical and physical properties of frozen herring fillets with regard to the condition of raw materials during processing and conditions in cold storage. Atlantic herring was processed before and after death solidification, and the fillets were stored under stable storage conditions (-25 ° C) and unstable conditions (at -25 ° C for 2 months, then -12 ° C for one month and then again at - 25 ° C for the duration of storage). To study the stability and physical properties of the products, water loss (drip), boiling efficiency and color were measured, in addition to which both light and dark fish muscles were measured for water resistance, pH, chemical composition, fatty acid composition, enzyme activity and evolution. The study showed that it is important for the fishing industry to ensure uniform and correct temperature control when products are stored in the freezer. Processing and freezing before death solidification, in parallel with stable storage conditions, has a positive effect on the quality and stability of herring falcons. In addition, the study confirmed that the fatty state of the herring muscle, often referred to as the dark muscle, is very sensitive to development. In order to extend the shelf life of frozen herring fillets, it is recommended that this muscle be removed in parallel with deep skinning.

Freezing and frozen storage has proven to be an effective method to preserve and prolong the storage life of seafood products. Production of frozen products provides all year around product availability although the catching is seasonal. There are several factors that can affect the quality and stability of frozen fish products, including the state of the raw material, processing methods and storage conditions. The aim of the study was to explore how physicochemical properties of frozen herring fillets are affected with respect to the state of the raw material during processing as well as storage conditions. Atlantic herring was processed and frozen pre- and post-rigor and stored at stable (-25 ° C) and abused storage conditions. To investigate the storage stability and physical properties of the fillets, thawing drip, cooking yield and color were evaluated, as well as proximate composition, fatty acid composition, pH and lipid degradation of the light and the dark muscle. The study demonstrated the importance of stable and controlled temperature during storage and transportation of frozen herring products. Processing and freezing pre-rigor, in combination with stable storage conditions, was shown to be beneficial in terms of preventing lipid oxidation, as well as reducing thawing loss and maintaining the cooking yield of the herring fillets.

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Reports

Thermal Performance of Corrugated Plastic Boxes and Expanded Polystyrene Boxes

Published:

01/01/2009

Authors:

Björn Margeirsson, Sigurjón Arason, Halldór Pálsson

Supported by:

EU ‐ project Chill on (project no. FP6‐016333‐2), AVS Research Fund, TÞS Research Fund and University of Iceland Research Fund

contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Thermal Performance of Corrugated Plastic Boxes and Expanded Polystyrene Boxes

Experiments were performed on the insulation value of two types of packaging for fresh fish fillets: 1) Corrugated plastic box (CP) and 2) Foam plastic box (EPS). The variable temperature around the packages was controlled in the experimental cold rooms and the temperature development outside and inside the packages was monitored with thermometers. Both individual boxes and whole pallets of boxes were examined, as well as the cooling capacity of ice mats, which are sometimes placed on top of boxes for transport from manufacturer to buyer. The cooling mats (ice mats) proved to be very effective in protecting the fish fillets from heat stress. Furthermore, the results showed the superior thermal insulation of the foam plastic box over the corrugated plastic box regardless of the use of cooling mats. In fact, the difference in insulation value is even more visible when using cooling mats. Experiments with fully stacked pallets of fish boxes (approximately 300 kg per pallet) showed that the average temperature rise of fillets can be double for a corrugated plastic box with a foam plastic box, provided that the surrounding air is 10 ° C hot and has considerable movement. Finally, it was shown that several hours. fluctuations in air temperature around an entire fishing board can cause a very uneven heat distribution within the position on the board.  

Experiments were carried out to compare the thermal performance of two different types of packaging for fresh fish fillets: 1) Corrugated plastic (CP) and 2) Expanded Polystyrene (EPS) boxes. The boxes containing fresh fillets were affected with dynamic thermal loads in air climate chambers. Meanwhile, the fillet temperature was monitored with temperature loggers. Both free standing boxes and whole pallets were affected with dynamic thermal loads in the study and the chilling effect of frozen cooling mats was studied by using them in some of the boxes. The frozen cooling mats proved very efficient for protecting fresh fish fillets against temperature abuse. Furthermore, the results show that the insulating performance of EPS is significantly better than of CP, independent of the usage of cooling mats. The difference in insulating performance between the two packaging types is actually exaggerated when cooling mats are used. The experiments with whole pallets revealed that the mean fillet temperature rise for a whole 300 kg fish pallet can be twofold using CP compared to using EPS, given that the movement of surrounding air is considerable and its temperature is 10 ° C. Finally, it was shown that in dynamic temperature conditions, the temperature distribution in a whole pallet of fish fillets can be far from homogeneous.

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