The invention discloses a preparation method of micromolecular active
collagen peptide, which comprises the following steps: (1)
cutting fresh leather into fragments, pretreating the leather with a
sodium bicarbonate solution, rinsing the leather with deionized water, and refrigerating and storing; (2) mixing
papain, bromelain, pancreatin, pepsase,
alkaline protease,
neutral protease and flavourzyme to obtain a compound
enzyme preparation; (3) performing high-pressure
steam sterilization on the leather at 110-140 kPa and 120-122 DEG C to obtain leather with the
hydrolysis degree of 75-85%, then adding
distilled water into the leather to obtain
mucilage, then adding a compound
enzyme preparation into the
mucilage, reacting for 5.5-6.5 hours at the pH of 6.8-7.2 and the temperature of 50-55 DEG C, and then performing
enzyme inactivation at the temperature of 85-95 DEG C; and (4) after the
reaction system is cooled to
room temperature, purifying and centrifuging the
reaction system, and taking clarified supernate, thereby obtaining the product. Different animal skins are treated, the proportion of
peptide fragments with the molecular weight smaller than 1000 Da of the prepared small-molecule active
collagen peptide is larger than or equal to 80%, and the
hydroxyproline content is larger than 3%.