Reports

Value adding technique - Drying of pelagic fish

Published:

13/12/2017

Authors:

Ásbjörn Jónsson, Cyprian Ogombe Odoli, Sigurjón Arason

Supported by:

AVS Fisheries Research Fund

Contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Value adding technique - Drying of pelagic fish

The aim of the project was to improve the processing process and the quality and safety of dried sardines produced in Kenya. Like looking at new products such as dried capelin from Iceland for possible export to Kenya. The results showed that it was possible to ensure the quality of dried products such as capelin in Iceland. During indoor drying, conditions such as temperature can be controlled, thus preventing protein deformation and fat development. The results also showed that sardines, which were dried outdoors in Kenya at higher temperatures compared to indoor drying, were of poorer quality, as protein deformation occurred along with evolution. On the other hand, market surveys in Kenya showed that a certain group of consumers liked dried capelin from Iceland and were willing to buy the product.

The objective of the project was to improve the process and quality and safety of dried sardines produced in Kenya. As well as introduce new products from Iceland like dried capelins a possible export to Kenya. Results showed that it was possible to control the quality of dried products like capelin in Iceland. By indoor drying, the conditions can be controlled, like temperature and providing denaturation of proteins and oxidation of fat. Results also showed that sardines dried in open air in Kenya with higher temperature compared with indoor drying, had lower quality, were denaturation of proteins and oxidation of fat occurred. Market research indicated that certain social groups of consumers in Kenya liked indoor drying capelin from Iceland, and were willing to by such product.

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Reports

Filleting capelin for developing marinated anchovies / Filleting capelin for developing marinated anchovies

Published:

01/12/2013

Authors:

Vigfús Ásbjörnsson, Óli Þór Hilmarsson, Ingunn Jónsdóttir, Guðjón Þorkelsson, Guðmundur Stefánsson

Supported by:

AVS Fisheries Research Fund reference number R 11 056‐11

Contact

Óli Þór Hilmarsson

Project Manager

oli.th.hilmarsson@matis.is

Filleting capelin for developing marinated anchovies / Filleting capelin for developing marinated anchovies

The project is about examining the preconditions for starting filleting capelin in the Icelandic fisheries sector with the aim of increasing the value of Icelandic capelin products. The project examines the position of markets and what comparable products exist today. We go into product development where capelin is hand-filleted and products from fillets are developed similar to what is known in the processing of anchovies in many parts of the world. All products of the project are evaluated by sensory evaluation experts and given the opinion of sensory evaluators. The products are also introduced on the market. Experiments are being made with filleting capelin in a capelin filleting machine, which is considered to be a prerequisite for the industry to have the opportunity to create added value from Icelandic capelin products with greater processing.

The project aim is to analyze the feasibility to start filling capelin in the Icelandic fish industry with the purpose of increasing the value of Icelandic capelin products. In the project the current state of the market is analyzed and what similar products are on the market today. New product development takes place in the project where capelin is hand filleted and similar products are developed as marinated anchovies. All products developed in the project are evaluated by experts in sensory and given opinions from sensory judges. The products developed are introduced on the market. Experiments are performed on filleting capelin in capelin filleting machine which is evaluated as the prerequisite for the capelin industry in Iceland to create increased value into the Icelandic capelin industry by filleting the capelin.

Report closed until 01.12.2015

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Reports

Oxidation in fish muscle - The role of phospholipids, proteins, antioxidants and the effect of boiling on oxidation in fish muscle

Published:

01/04/2008

Authors:

Rósa Jónsdóttir, Margrét Bragadóttir, Guðrún Ólafsdóttir

Supported by:

RANNÍS Research Fund

Contact

Rósa Jónsdóttir

Research Group Leader

rosa.jonsdottir@matis.is

Oxidation in fish muscle - The role of phospholipids, proteins, antioxidants and the effect of boiling on oxidation in fish muscle

The aim of the project was to increase the understanding of the effects of oxidation in fish muscles, which reduces the taste and nutritional value of fish. The effects of added natural antioxidants or antioxidants were assessed to improve the stability of fish products and thus increase the possibility of using fish in prepared dishes. A phospholipid model from cod was used to examine the effects of stimulants (hemoglobin from cod and char) and inhibitors in the liquid phase from capelin and Icelandic algae. The effect of boiling and added anti-corrosion substances on the taste properties and the formation of a so-called heating taste in boiled fish mince was also examined. The effect of oxidation on membrane phospholipids and proteins in the fish muscle model and in the fish mince during heating and storage was measured by sensory evaluation, color measurements, conventional evolution measurements (TBA), gas spectrometry measurements to identify volatile odorants and electrophoresis capillary capillary peptile and amino acids that affect taste and bioactivity. The relationship between these factors was examined to explain and better understand the oxidation process in fish muscles and the factors that limit the shelf life of prepared fish products. The main negative effects of oxidation on fish quality were the formation of odorants, mainly aldehydes, which are fatty acid degradants. Membrane fat in lean fish can therefore have a significant effect on the taste quality of prepared foods, despite being in small quantities. Oxidative stimuli such as blood in the flesh and boiling led to faster oxidation, which shows that with proper bleeding and mild heat treatment, oxidation could be limited and the taste quality of fish could be better maintained. In addition, oxidation can be reduced through the use of antioxidants. Measurements of the antioxidant activity of capelin broth in a fish muscle model showed that variable external factors such as seasonal fluctuations and the treatment of capelin raw material can affect the antioxidant activity. A novelty in this project is a basic study of the effects of capillaries and algae, as well as changes in the decomposition products during welding, which have a direct effect on the taste quality of the product. Research in this area is being continued in new projects that focus on better looking at natural antioxidants from capelin and algae, as well as their health-promoting effects.

The aim of the project was to study the effect of heating on oxidation of phospholipids, and the role of antioxidants in fish muscle to influence sensory quality and nutritional value. A phospholipid model from cod was used to study the effect of pro-oxidants (hemoglobin from cod and trout) and antioxidants in aqueous fraction of capelin and in seaweed extracts. The effect of heating and the addition of antioxidants on the sensory quality and the development of warmed-over-flavor (WOF) in fish mince were also studied. The development of degradation compounds in washed cod model system during storage and heating was studied by sensory analysis, color measurements, traditional lipid oxidation analysis (TBA) and gas chromatography analysis to identify volatile compounds. Capillary electrophoresis (CE) was applied for the analysis of peptides and amino acids that influence the sensory quality and bioactivity. The correlation between these analyzes was studied to better understand the oxidation processes in fish muscle and to explain factors reducing the shelf life of ready-to-eat fish products. Quality defects related to oxidation of polyunsaturated fatty acids and formation of volatile compounds like aldehydes contributing to rancidity and color changes were enhanced by pro-oxidative effects of blood and cooking. Membrane bound phospholipids are therefore of concern as precursors for off flavor and quality defects in lean fish despite of low fat content. Capelin broth appeared to have antioxidant effects in fish model system whereas press juice from whole capelin exhibited pro-oxidant effects. The outcome of this project is increased knowledge on oxidation in fish muscle to underpin the development of healthy and tasteful fish products of high sensory quality and nutritional values fulfilling the needs of consumers. Continued studies have been established in new projects to further characterize the antioxidant properties and possible health effects of capelin and seaweed extracts.

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