Method for grading molecular weight of anglerfish skin collagen peptide

The invention discloses a method for grading the molecular weight of anglerfish skin collagen peptide. The method comprises the following steps: soaking anglerfish skin in dilute alkaline liquid; taking out, then washing with water and draining; performing enzymolysis on the anglerfish skin; after deactivating enzyme, adding active carbon for debitterizing and decoloring; entrapping collagen peptide with the molecular weight being more than 10,000 Daltons from the filtrate obtained after the active carbon is filtered out, by a first-level plate type ultrafiltration membrane; entrapping collagen peptide with the molecular weight being more than 2,000 Daltons by a second-level roll type ultrafiltration membrane; and entrapping collagen peptide with the molecular weight being more than 200 Daltons by a roll type ultrafiltration membrane. According to the method, the anglerfish skin is hydrolyzed by using pepsase and flavourzyme step by step during enzymolysis, and the collagen peptide with the molecular weight in broad distribution is subjected to effective molecular weight grading processing after enzymolysis, so the collagen peptide with different molecular weight segments can be obtained and can be effectively utilized.