Method of Enzyme Production from the Hepatopancreas of the Red King Crab (Paralithodes camtschaticus): The Effect of Temperature and Defatting Conditions on Enzymatic Activity

Processing crabs for meat generates large quantities of waste (secondary raw materials). Internal organs are typically discarded, which causes environmental problems and highlights the need for the integrated use of marine bioresources. The red king crab hepatopancreas is an excellent source of various proteins, including enzymes with different substrate specificities. In this study, an improved method was developed for producing a complex enzyme preparation from the hepatopancreas of red king crab (Paralithodes camtschaticus) harvested by a large industrial enterprise in the Barents Sea. Physicochemical analysis revealed high protein (16%) and lipid (10%) contents in the hepatopancreas. The developed method involves centrifugation to rapidly separate the fat fraction from the aqueous protein fraction and acetone washing to remove residual lipids. The use of low temperatures (0 to 5 °C) for autolysis is justified to prevent a decrease in enzymatic activity of the final preparation. Obtained enzyme preparations were analyzed for protease, collagenase, and endo- and exochitinase activity. They exhibited high proteolytic (Aprot = 252 μmol Tyr⋅g−1⋅min−1), exochitinolytic (Aexo = 0.94 μmol GlcNAc⋅g−1⋅min−1), and collagenolytic (Acol = 210 mIU·mg−1) activities. It has been shown that enzymatic activities depend on seasonality (winter and summer) of the crab catch, which is due to differences in the physiological processes of crabs during seasonal cyclical temperature changes in their natural habitat. The developed process flowsheet for producing an enzyme preparation from the red king crab hepatopancreas can be used as the basis for technology by enterprises engaged in the comprehensive processing of marine bioresources.