Fluorine being present in the exoskeleton of crustaceans, and especially krill represents a problem for using krill as a source for food, feed, food additives and/or feed additives. There has been developed a process for removing such fluorine from krill material by subjecting the krill to disintegration and to an enzymatic hydrolysis process prior to or simultaneously with a removal of the exoskeleton particles producing a fluorine-reduced product. Inherent in the disclosed process is the ability to process krill material with a high polar lipid content for producing superior quality, low fluorine, products suitable for the food and feed as well as the pharmaceutical, neutraceutical and cosmetic industry. The disclosure particularly relates to a process for for removing fluorine from a catch of crustaceans, wherein the crustaceans, immediately after having been landed and at a temperature of around ambient temperature of the water, are disintegrated into smaller particles, and to the disintegrated material there is added fresh water and a proteolytic enzyme or proteolytic enzyme composition, said mixture being heated to a temperature optimal for the activity of said proteolytic enzyme or proteolytic enzyme composition, and at which temperature the added enzyme(s) is/are allowed to work for no longer than 100 minutes, the hydrolysed material being fed to a separating device for separating solids from the processed material, and through this removal of the solids fraction 10 thereby reducing the fluorine content of the remaining proteinaceous material by at least 85%, the added (exogenous) and natural (endogenous) enzymes in the hydrolysing disintegrated proteinaceous material being deactivated before, during, or after the removal of the solids fraction from the enzymatically processed material, said deactivation being conducted alternatively by adding inhibitors, by removing co-factors, or by thermal inactivation.
