Scientist Tone Aspevik in Bergen has tested and compared several enzymes based on cost and the enzymes’ ability to cleave salmon proteins. Photo: Øyvind Ganesh Eknes.

Project Year 2016

Promising proteins

Today many companies use off-cuts from fisheries, aquaculture and meat production, but often with little financial gain. We see a potential for much greater gains. In the future off-cuts will be regarded as a commodity, not leftovers, according to Nofima scientists.

Nofima is researching how the food industry can use residual raw materials and add value through bioprocessing, while at the same time reducing the loss of valuable nutrients, such as proteins that can be used for feed and food.

The proteins in freshly slaughtered fish and animals are of excellent quality. To exploit this potential once the fillets have been removed, the residual parts must be treated properly. In addition, the process of extracting the proteins from the carcass must be optimal. Enzymatic hydrolysis is one such process. To ascertain whether this process is optimal, it must be measured and the final product must have the appropriate qualities, including flavour.

A top-quality end product means more of the residual raw material is used for human consumption and other better paying markets. If the end product contains bioactive substances, we can determine whether it can be used in feed, health foods or medicinal products.

The research is still ongoing, but Nofima already has some interesting findings.

Enzyme-tailored products

In enzymatic hydrolysis, enzymes are a catalyst that open up the protein structure and cleave the proteins. The scientists choose the enzyme based on the kind of end product they want.

“By using enzymes, which act like tiny biological scissors, you can cut up the proteins found in residual raw materials into smaller peptides. These peptides are more easily soluble in water and therefore easier to exploit in products such as dietary supplements, soups and baby food than intact protein,” explains Tone Aspevik.

She completed a PhD in optimisation of the enzymatic hydrolysis process in 2016.

Aspevik conducted a systematic study to determine which enzymes and process conditions yield protein powder with an acceptable flavour at the lowest cost. Her project focused on protein powder from salmon trimmings. The knowledge gained from this work is now openly available for industrial use.

An important part of the solution to ensure good quality of the end product is to have analysis methods that enable better continuous monitoring of the protein quality. A team of scientists at Nofima, led by Nils Kristian Afseth, have developed a brand-new, promising analysis method based on spectroscopy. This technology uses light to analyse the chemical composition of samples without affecting the process or the raw material.

The scientists are using this technology to study the changes in protein structure and chain lengths, enabling the scientists to increase their understanding of what actually happens during enzymatic hydrolysis.

Real-time quality analysis

“The difference between the method we are working on and the existing methods is that our method makes it possible to verify the quality during production. In this way, our industrial partners can continuously adjust the process, resulting in products with optimal quality and maximum yield,” says Afseth.

To be able to find the most suitable peptides at any given time, the Nofima scientists are working in a multidisciplinary team.

In 2016 Nofima established a multidisciplinary collaboration as part of a self-funded research initiative within the circular bioeconomy called Peptek, headed by Ragnhild Dragøy Whitaker, head of marine biotechnology research.

“There are major opportunities for increased exploitation and profits by processing off-cuts to create high-quality protein. In the future off-cuts will be regarded as a commodity, not leftovers,” concludes Afseth.

More useful research results