Fish products and Byproducts Technology

Unit 9 - Fish meal and fish oil

9.8.1.b. Dry reduction Process
In this process the raw material is "dried" (in cooker/drier) to remove the water (essentially the steam cooking process in the fishmeal wet rendering process. The resultant dry cake is then pressed to remove any oil. Because the water has been removed, the lipid fraction can contain high levels of phospholipids. The phospholipids normally hydrate in the wet rendering process and are recovered with the water fraction. In the dry rendering process, they are not hydrated and therefore remain dissolved in the lipid or oil fraction. Since there is interest in the fish phospholipids, it is possible to produce a PL fraction by hydrating the oil (also called degumming).