What treasures can be found in leftovers from the herring industry?
What treasures can be found in leftovers from the herring industry? Photo: Lars-Åke Andersen/Nofima

Rest raw material

There’s an enormous potential to use rest raw material from food production more efficiently. Our scientists are working to develop technology and methods to increase the value and use of rest raw material.

Contact person
Portrettbilde av Ragnhild Dragøy Whitaker
Ragnhild Dragøy Whitaker

Research Director
Phone: +47 977 49 562

Contact person
Portrettbilde av Mari Moren
Mari Moren

Research Director
Phone: +47 922 37 121

Contact person
Portrettbilde av Nils Kristian Afseth
Nils Kristian Afseth

Senior Scientist
Phone: +47 958 40 641

Rest raw material from food production is what remains after the edible part of the animal, fish or plant has been removed. A great deal of rest raw material is already used, but it often gives only poor yield or represents low value.


In order to use rest raw material more efficiently, and to obtain a higher price, new processes and methods of processing, analysis and post-treatment of the raw material, and new products for certain markets are required. These challenges pose stringent demands on the quality of the rest raw material throughout the value chain, through the processing right up to the final product.

While the parts that are to be eaten are carefully handled according to applicable regulations, less focus in often placed on the parts that remain. The way in which the rest raw material is handled determines the types of product that can be produced. By optimising the processes in which the rest raw material is produced, it is possible to ensure that the rest raw material achieves the quality that is necessary for the various products.

Nofima is working to ensure that all raw materials are used beneficially. Our research contributes to increasing the value and range of use of the rest raw material.


Hydrolysis and fractionating are often used to process rest raw material. Enzymes are used in a hydrolysis process to modify specific components in the material before the biomass is separated into three fractions, or “phases”:

  • Liquid phase: consisting of peptides (chains of amino acids) and water-soluble compounds. It is possible to create peptide concentrates from the liquid phase, and to extract antioxidants, vitamins and other fine chemicals. These can be sold on several markets, such as the feed, health food, cosmetics, industrial and medical markets. Proteins that remain in the rest raw material can also be processed in several ways, and used in food products such as protein powder, packet soup, baby foods, etc.
  • Fat phase: consisting of oils and fat-soluble compounds. Some of the fat-soluble compounds in the fat phase are removed, while others, such as fat-soluble vitamins, can be used. Marine oils contain healthy polyunsaturated fatty acids, and there is a large market for these oils.
  • Solid phase: consisting of solid substances such as bone and shells. Products such as bone meal, shell meal, gelatin and collagen can be produced from the solid phase.

Processed rest raw material can also be used as growth medium for bacteria and moulds. In this case, bacteria and mould are added to the rest raw material and “digest” it, such that it becomes new products. This method can be used to produce such products as proteins, carbohydrates, polyunsaturated fatty acids and bioplastics. The fermentation processes are monitored by specially designed spectroscopy methods to be able to determine the products that particular types of bacteria and mould make, and to optimise the choice of rest raw material to obtain the best possible products.


Some processed rest raw material can be used also in products that have a documented effect on animals or people. If it is to be used in health products or medicine, the first stage is to investigate whether the raw material is bioactive, i.e. whether it has a desired effect in various processes. We also investigate in such analyses the inhibition and activation of enzymes, the modification of intracellular processes and the modification of cell growth.

If the rest raw material is bioactive, further research can be carried out using other methods. We have, for example, processed rest raw material to be used in feed, and we have documented its effects on fish and animals in feeding trials.

Measurement methods

In order to optimise the value of rest raw material and to be able to use the right product in the right market, all parts of the processing must be analysed. The scientists at Nofima use modern research equipment for these analyses, and also develop their own methods. One such method is rapid light measurements using spectroscopy. These methods are used to monitor the processes to ensure that the rest raw material is used optimally, and that the resulting product satisfies the quality requirements.

From laboratory scale to product development

If good results are obtained in the laboratory, the next stage is to determine whether the results can be used on an industrial scale. This is a challenging transition with which Nofima works intensively. We often work together with industrial partners, developing products from the processed rest raw material. Together with customers, our scientists have developed several products within feed, food and health food.

When the rest raw material has been processed and analysed, we can use our sensory panel to make sure that the product has the desired sensory qualities, such as taste, smell and texture. We also have our own scientists who work with quality and packaging for the product.

Nofima offers:
  • research and product development at all stages of the value chain: from raw material via processing right up to the final product on a suitable market.
  • evaluation of alternative uses for rest raw material
  • optimisation of raw material handling
  • process and product development
  • development of measuring techniques and systems for process control
  • development of prototypes in the laboratory and in pilot plants
  • product formulation
  • testing in the food industry and in feed applications
  • calculation of production costs and investment analysis
  • chemical, physical, sensory and bacterial product documentation
  • biological tests based on fish and cell models in culture
  • scaling up and test runs at semi-industrial scale
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