A stagnating global fishing industry and increasing demand for fish products has over recent years led to an exponential growth in aquaculture. It is vital to minimize any adverse effects of aquaculture on people, the fish, and the environment and to have sustainable production. An important aspect is the fish food that is used. Up until now this has contained high quantities of fish meal and fish oil. The desire for sustainability means that there are excellent opportunities for increased use of plant raw materials in fish feed.
This research project will study the use of residual plant-based materials after plant oil recovery as additives in fish feed for salmonids. These plant-based products include press-cake after the recovery of, for example, sunflower oil and rapeseed oil. Large quantities of these residual materials are available at low cost from the processing of native crops and they contain significant concentrations of valuable ingredients such as proteins, lipids, and anti-oxidants.
The challenge in this research project is to adapt and optimize the process parameters and formulations for the new raw materials. Both the raw fiber content and polyphenol content of the press-cakes are important. They can be altered by fractionation steps.
In order to manufacture the fish feed pellets, the extrusion process will be modified to produce stable pellets having specific properties. Here, the technological and nutritional properties and the acceptance of the fish feed are of decisive importance.
The aim of the project is to develop a fish feed containing plant-based residual materials which meets the current requirements regarding economic viability, sustainability, animal health, efficiency of production, and product quality.