The demand for healthy marine omega-3 polyunsaturated fatty acids (PUFA) for feed, functional foods, and pharmaceutical products is increasing. For many years fish oil produced from wild fish has been the most important source of marine omega-3 PUFA. However, the production of fish oil has been stable during the last decade and is not expected to increase due to sustainability reasons. Therefore, to meet the shortage in marine omega-3 PUFA expected in the near future, new sources of these fatty acids for feed, food and pharmaceutical products are required.
In November 2012, a joint meeting between the Marine Lipid Division from EuroFedLipid and the Nordic LipidForum was held in Copenhagen in order to share knowledge about recent progress in this area and to discuss future solutions to meet the demands for omega-3 PUFA. The one and a half days programme included 24 oral presentations and 10 posters. The first two presentations at the meeting gave an overview of the worldwide situation for omega-3 supply and the future demand. It has been estimated that by 2025 the demand for crude fish oil for dietary supplements and functional foods will reach 450 000 tons/year, which accounts for almost 50% of today's global fish oil supply. At the same time, the demand for marine omega-3 PUFA for aquaculture will also increase significantly. The current production of marine omega-3 PUFA cannot meet these demands. Two presentations provided an overview on the current status in developing transgenic plants that are able to produce long chain omega-3 PUFA. From these presentations, it was clear that this strategy is possible, but further development is still necessary to increase yields. Nevertheless, it is expected that such oils will be available on the market within the next 5–10 years. Other new sources such as microalgae, krill, discarded species (by-catches from fisheries), rest raw materials and waste water from, e.g. the herring industry were also discussed. Omega-3 rich oils produced by heterotrophic algae are already commercially available today and are successfully used for example in infant formula. There is an increasing interest in phototrophic microalgae as these can be grown with CO2 as the only carbon source. At the meeting it was demonstrated that such microalgae can be used in animal feed. Krill oil is a good source of omega-3 PUFA, which to a high extent are found in the phospholipid form, which seems to be more bioavailable than omega-3 PUFA in the triacylglycerol form. Oxidation mechanisms in krill oil are, however, more complex than in fish oil as the lipids can degrade to form Strecker aldehydes and pyrroles. Therefore, the traditional methods for measuring oxidation (PV and AV) are not suitable for quality control of krill oils. Discarded species and wastewater from the herring industry were shown to be able to provide substantial amounts of omega-3 PUFA. Using discarded species and rest raw materials from the fish industry, oils can be extracted in the same way as from traditional fish used for fish oil production. Regarding wastewater, developments within up-concentration/filtration techniques are required before this source can be utilized commercially. Such development is underway. Several presentations concerned the possibility of feeding fish with alternative feed sources to fish meal and fish oil, and the effect on fish composition and metabolism was discussed.
Six papers from the meeting are published in this special collection. The collection is published in two parts, three papers were featured already in the September issue and this issue brings the second part. The Collection is accessible online at http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1438-9312/homepage/novel_sources_of_omega-3.htm. Hopefully, these articles will be a source of inspiration to more research and development in this important topic as this is urgently needed.
Bente E. Torstensen