Herring is one of the most important fish species in the North Atlantic and Baltic Sea, with an annual catch exceeding 2 million tonnes. Although a large part of these fish is used for human consumption, as much as 85% of the herring is used for industrial production of fish meal and fish oil.
There is a general wish to increase the utilisation of herring for human consumption. Thus, it was important to study the various parameters which influence the quality of herring, and in particular how these paramenters are controlled by biological factors. A major reason behind quality problems arising during post harvest handling of herring is its high content of compounds that efficiently catalyzes the development of rancidity, pigmentation, texture changes and loss of nutritional value.
Improved quality will result in increased competitiveness of the Nordic fish processing industry and would improve the attitude among the consumers towards herring products.
The general objective of the project was to improve the quality and quantity of herring to be used for food production by investigating how natural variation in raw material characteristics affects post harvest quality. Attention was given to the quality immediately after landing and the quality after period of frozen storage.
Results and conclusions
This project has shown that the geographically diverse stocks of herring that are used by the Nordic herring industry is less diverse than expected when it comes to basic composition, pre-storage quality and post storage quality. Of much higher importance for the various quality parameters was prolonged frozen storage at -20°C. Thus, for any application where a frozen herring material is preferred, the pre-processing storage should be minimized.
As fishing from many of the European fish stocks can not be increased, increased and improved utilization of the available sources are, and will be important. The herring stock have a great potential for a better utilization. By improving the quality, an increased proportion of herring can be marketed at the highest prices, this will improve economic benefits of both the producers in the industry and the fishermen. However, it will in particular benefit the consumer who get a better and more nutrious food for a low price compared to other animal products.
The knowledge created from this project is important for marketing of frozen herring fillets and for the producers of herring products. Also the project has largely increased the theoretical knowledge concerning long-term frozen herring fillets; especially the relations between the structural, nutritional and sensorial quality of herring.
Project duration: July 2003 - November 2007