Recently, the collaborative project "Equal distribution of salt in salted fish muscles" was completed, which was supported by the AVS Fisheries Research Fund (R 052-10). The research project was carried out in collaboration with the Icelandic Saltfish Producer (ÍSF), the Institut National de la Recherche Agronomique (INRA) in Clermont-Ferrand in France and Matís.
The main goal of the project was to reduce the frequency of defects in wet-processed salted fish due to the distribution of salt and water around the muscle and to develop a product that is suitable for new markets with the help of the latest technology.
Icelandic salted fish products have long been sought after and prominent in foreign markets. This strong position can be traced to the great development of processing and processing in recent years, which have completely changed all handling of production. Wet-processed salted fish has been the product that has yielded the highest relative export value of marine products, but the vast majority of salted products exported from Iceland are produced with this new processing method. Most of these products were exported to Spain, where wet-processed salted fish is popular and the market share of Icelandic products is good there.
It is important to maintain a good market position in existing markets and to ensure Icelandic producers the advantage they have had over products from Norway and the Faroe Islands, but also to enter new markets by developing new products that suit the relevant market. However, there are other needs in the Portuguese and Brazilian markets, where the demand for dried salted fish is higher. These markets are large and it is therefore desirable for Icelandic producers to increase their share in these markets. For this, however, further process control of drying and dehydration needs to be worked on, based on the salting methods used in Iceland. It can be estimated that the best processing and processing processes, from raw materials to final products, can promote a quality product that is suitable for this new market for Icelandic salted fish products. There have also been regular complaints about acid-salted saddles that can be traced to the distribution of salt around the muscle.
The project paid special attention to the distribution of salt and water throughout the salted fish muscle and how different treatments affect this delicate balance and the quality of the final product. One of the aims of the project was to find a reason for the aforementioned defects and to prevent their formation through improved methods of action. The latest technological advances in food research (Nuclear Magnetic Resonance (NMR) and magnetic resonance imaging (MRI)) were used, as well as traditional chemical and physical property measurements in order to gain the best possible understanding of the effects of different treatment and processing methods on the quality of salted fish products. The MRI technology provides an insight into the structure of the muscle and the distribution of water and salt around it graphically. One of the main advantages of this technology is that it has no effect on the samples and the samples are therefore undamaged after analysis. In addition, more detailed quantitative measurements of the effects of processing methods on the mobility and distribution of salt and water, inside and outside muscle cells, were performed using NMR technology.
The results of the project gave a good insight into how different processing methods affect the distribution of salt in the fish muscle and at the same time the quality of the final product. Furthermore, the results of the project underline that MRI and NMR technology are powerful methods for evaluating the processing properties of products, as well as for maximizing the effectiveness of processing methods.
Figure 1. Flat salted fish
Figure 2. NMR measurement equipment
Figure 3. Cross section with NMR
For further information Magnea G. Karlsdóttir at Matís.