Persistent organic pollutants (POPs) are toxic chemicals that accumulate in the fatty tissue of living organisms. High levels of POPs have been found in several fish species caught in North European areas and consequently in fishmeal and fish oil produced from industrial fish and by-products. POPs in fish derive predominantly from their diet and fishmeal and fish oil are the most important sources of these contaminants in fish feed formulations.
POPs relevant for human health include dioxins, PCBs and pesticides. New legislations on the maximum permitted levels in animal feed have been implemented by the European Commission (EC) and to comply the feed compounders are using increasing levels of South Pacific fishmeal and fish oil or non-marine feed ingredients with natural low contamination levels. Although only a minor part of the North European fish oil and fishmeal has content above the maximum levels, the need for decontamination will disfavour the producers on a world basis.
Financial support and collaboration:
The research project DECONTAM is a knowledge-building project with user involvement (KMB project) funded by the Norwegian Research Council under the AQUACULTURE - An industry in growth program in collaboration with the Fishery and Aquaculture Industry Research Fund (FHF) and the industry partners Pronova Biopharma, Marine Harvest and Egersund Sildoljefabrikk.
The project also involves collaboration with the University of Bergen, University of Iceland, Vrie University (Holland) and Biosense Laboratories.
The main objectives of the project are to optimize a novel oil-based leaching process to reduce the POPs content in fishmeal without loss of protein quality, and to identify optimal conditions for decontamination of the oil used in the process. The leaching operation is performed by contacting intermediate products (presscake and decanter solids) in the fishmeal process by fish or vegetable oil. The POPs are transferred to the continuous oil phase where it can be removed based on short path distillation or activated carbon adsorption.
Included in the project is also development of a process simulation model to be used as a basis for industrial up-scaling. The leaching process has several advantages compared to the present industrial practise, i.e. removal of the POPs containing oil in the fishmeal by organic solvent (hexane) extraction. This will include the possibility of easy integration in an existing fishmeal processing line, use of a safe and non-flammable extraction medium and lower investment and operation costs.