Sileshi Wubshet and Rita Lima in front of the vessel used for the production of peptides from chicken carcasses. Photo: Joe Urrutia © Nofima

Project Year 2018

Food as medicine

 Raw materials and process optimisation  

Peptides, which can be extracted from chicken carcasses, may help regulate blood sugar level in the same way as some diabetes medicines.

Everyone agrees that using all the raw materials from chicken, including the carcass, is good for the environment. Now it seems it may also be good for your health. There is growing awareness of the opportunities afforded by making better use of residual raw materials.

Like looking for needles in a haystack

The two Nofima scientists Sileshi Wubshet and Rita Lima are studying residual raw materials from chicken and milk and have identified a number of peptides that appear to have the same effect as some diabetes medications.
It is a laborious process, and the trick is to develop methods that make it possible to identify and extract the exact peptides the scientists are looking for.
“We know that many of the substances in residual biomass have health-enhancing properties, but they are difficult to identify and separate. Out of hundreds of peptides, we have identified 19 that can potentially help regulate blood sugar and manage type 2 diabetes,” says Sileshi Wubshet.

Less side effects

There has been a significant increase in the number of people with type 2 diabetes in the past ten years. In Norway alone, some 200,000 people have a type 2 diabetes diagnosis. The disease develops when the cells that produce insulin stop working properly.
This reduces insulin production or means that the body is no longer able to respond to insulin, leading to a rise in blood sugar. Prolonged high blood sugar has many negative health consequences.
DPP4 inhibitors are a relatively new type of diabetes medicine. They help stabilize blood sugar and prolonging the effect of two peptide hormones that promotes the release of insulin. Unfortunately, DPP4 inhibitors also have several negative side effects, such as hypoglycaemia, headache and respiratory infections.
“We have identified peptides in residual raw materials from chicken processing that have the same function as DPP4 inhibitors, and the hope is that they can be as effective – with less side effects,” says Rita Lima.
Peptides are molecules consisting of a chain of amino acids. Peptides are basically mini proteins, and the main difference between peptides and proteins is that peptides have fewer amino acids. The first thing the scientists had to do when looking for favourable properties in the residual biomass was to break the proteins down into smaller parts, i.e. peptides.
This is done through enzymatic hydrolysis, a process whereby water and selected enzymes are used to split proteins, making them easier to digest. This also results in changes in the functional properties.
The next step after the peptides had been separated out was to start looking for peptides with the exact properties the scientists were interested in.
“We separated the peptides from one another on the basis of their chemical and physical properties using chromatography, which makes it possible to both separate and identify substances in very complex samples,” explains Rita Lima.

Tests on cells

The scientists have tested these peptides in cell models, with promising preliminary results. Using cell models has several advantages. The models allow the scientists to study everything at the cellular level, making it easier to understand how and why the cells react as they do.
The next step will be to find out whether there are any toxic effects associated with the peptides. Tests will have to be done on diabetic mice to see if the peptides have the same effects on them as they did on the cells. Finally, human trials will have to be carried out.
“The goal is to be able to add the peptides to foods to make them diabetic-friendly,” concludes Sileshi Wubshet.

University of Copenhagen, Denmark and Norilia, Norway

The Foundation for Research Levy on Agricultural Products (FFL) and the Research Council of Norway (NFR)

More useful research results