Oil quality of by- products of marine fish during processing methods

Abstract

By- products that are not regarded as ordinary saleable products (fillet, round, eviscerated or beheaded fish), but which can be recirculated after treatment. Normally oil is produced from by-products of marine fatty fish species such as cod, anchovy, capelin, sardine, salmon, tuna, mackerel, Norway pout, Atlantic herring, sand eel etc. It is possible to extract oil by different process such as wet reduction, hydrolysis, silage, dry rendering and acid - alkali aid. Fish roe has high concentrations of lipids. Hydrolysis was better than wet rendering method as there was a chance for lipid oxidation in the wet rendering method. High quantity and quality of phospholipids were generated from the lipid fraction in the dry rendering process. To ensure high quality of produced products, it is important to process by-products immediately after production. It is also needed to increase the utilization of marine by- products by increasing knowledge on the chemical composition and stability of the by- products.