This is the conclusion of four and a half years of work in the EU project WaSeaBi with the participation of a total of 13 partners from universities and fishing industry companies in Denmark, Sweden, Belgium, France, and Spain. DTU Professor Charlotte Jacobsen has been in charge of the project.
“There are plenty of nutrients left in the fish after the fillet has been removed. In some parts of the world, it’s common to eat the head. You can also make soup from it, and fish oil is already made from fish entrails. But there are many other options for exploiting the side streams. The important thing is that we ensure good quality—and we need to show consumers that these parts can also be used to make healthy and tasty products,” she says.
The tangible solutions developed in the project have been the result of the participating companies’ side streams and challenges.
New flavour ingredients
For Royal Greenland, it was about utilizing the parts of the cod that remain after the fillet has been removed. Here, a good flavour ingredient was created from the carcass and head by adding enzymes to them—a so-called enzyme hydrolysis process—which gives a more intense umami taste and a greater yield than if you had just boiled them.
However, a number of requirements must be met if companies are to start exploiting these side streams, including further training of staff and investments and space for the necessary equipment.
“We at DTU can help them realize their objectives, obviously not with money, but with formulating new projects and writing applications, and we’re also ready to assist with technology and knowledge transfer,” says Charlotte Jacobsen.
Lower expenses
Danish Jeka Fish, which is based in Lemvig and is one of Europe's largest producers of salted cod, wanted better utilization of the brine in which the fish is placed before salting. Proteins, various salts, and polyphosphate are added to the brine, which must be sent to the treatment plant after use. This entails additional costs for the company in those cases where the water does not comply with the threshold values for wastewater discharge.
“When you’re running a fish processing business in Denmark, you need to focus on all your residual products and by-products and see if you can get some more value out of them. Simply to achieve more profitable operations,” says Support Manager Anders Meyer about the company’s decision to participate in the WaSeaBi project.
If you could instead separate the additives and reuse them in production, it would benefit both the business and the environment. And the project has shown that this is doable.
DTU researchers have helped develop two processes for water treatment and for increasing the concentration of the nutrients protein and phosphorus so that they can be reused. The technology is now being expanded from laboratory to large-scale testing.
"We were a little delayed by the coronavirus pandemic and therefore didn’t fully conclude the project,” says Anders Meyer. "But we’ve obtained a very large volume of data, which we’re now in the process of analysing, and we will test, on a larger scale, a method for treating the water and increasing the concentration of the nutrients protein and phosphorus.”
Jeka Fish is also looking into the possibility of starting a new project with DTU, possibly in collaboration with the innovative climate centre Klimatorium in Lemvig.
Longer shelf life
The Spanish company Pescados Marcelino wanted to utilize the highly nutritious cooking water from mussels instead of having to pay to dispose of it. The company is using some filters that purify the water so that they are left with a concentrate with a very fine taste. It now needs to be further developed so that it can be sold as a flavouring ingredient.
Especially fatty fish such as herring and salmon contain a lot of omega-3 fatty acids, which tend to react with the oxygen in the air and form rancid flavours that we and our bodies do not like.
Therefore, the project has also worked to develop a new antioxidant liquid which can be used to treat the carcass and other residual parts of the fish so that they stay fresh until they are processed into new products.
Support tools
In addition to the practical and technological solutions, the project has also resulted in tools that can help companies with the necessary technological, legal, financial, and sustainability considerations before they decide on how to exploit their side streams.
The tool has been developed by DTU in collaboration with the Spanish research centre AZTI and Ghent University. It has been tested on several of the cases under the project.
Finally, an EU guideline has also been drawn up for the development of new ingredients from the side streams of the fishing industry.
The WaSeaBi project has been concluded, but the work with side streams is far from over, Charlotte Jacobsen ascertains.
“WaSeaBi was only the beginning. There is much more to be done. We have several applications pending together with different companies, and we’ve just received money to continue our collaboration with, among other partners, Sweden Pelagic and Chalmers University of Technology as well as the Danish company Werner Larsson Fiskeeksport A/S. In fact, we plan also to make new flavour ingredients out of herring.”
