Extraction method of collagen polypeptide and active calcium in walleye pollock bone

The invention discloses an extraction method of collagen polypeptide and active calcium in walleye pollock bone. The method comprises the following steps: (I) pretreating the raw material; (II) preparing bone collagen polypeptide through the substeps of (1) soaking fish bone in a NaOH solution and then carrying out high-temperature and high-pressure treatment, (2) extracting the bone collagen, (3) carrying out treatment via a high-voltage pulsed electric field, and (4) carrying out enzymolysis by firstly adding composite collagen protease for enzymolysis, then adding flavor protease for enzymolysis, decolorizing and deordorizing, carrying out spray drying to obtain the collagen polypeptide; and (III) preparing active calcium in fish bone through the substeps of (1) extracting tartaric acid, (2) extracting tartaric acid again, and (3) combining the extracted tartaric acids to prepare the active calcium in the fish bone. Through the extraction method, the disadvantages of thick fishy smell, bitter taste and unf