The invention discloses a preparation method of an
antioxidative peptide of a hairtail. The preparation method comprises the following steps of 1, adding water into hairtails, and
mincing the hairtails into hairtail paste, 2, adding the hairtail paste into an enzymolysis tank, and adding endoprotease into the hairtail paste for
hydrolysis, wherein the
mass of the endoprotease is 0.2 to 0.9% of the
mass of the hairtails, 3, carrying out
centrifugation of a
hydrolysate obtained by the step 2, and collecting a supernatant, 4, carrying out
microfiltration of the supernatant, adding the micro-filtrated supernatant into the enzymolysis tank, and adding excision
protease into the enzymolysis tank for
hydrolysis, wherein the
mass of the excision
protease is 0.1 to 0.9% of the mass of the hairtails, 5, in the
hydrolysis, pumping an enzymatic
hydrolysate into an
ultrafiltration membrane separator from the enzymolysis tank so that the enzymatic
hydrolysate can be circulated at a flow of 0.1 to 0.5L / min, and 6, collecting an
ultrafiltration membrane permeate, carrying out reduced pressure concentration until a volume of the
ultrafiltration membrane permeate is 1 / 10 to 1 / 5 of the original volume, keeping a temperature of -18 to -20 DEG C for a night, and carrying out
freeze drying at a temperature of -60 to -65 DEG C under the pressure of 0.005 to 0.0054 mbar to obtain the
antioxidative peptide of hairtails. The
antioxidative peptide of hairtails has strong antioxidation activity, a
hydroxyl radical removal rate of 82.0%, a
superoxide anion radical removal rate of 85.2% and a
DPPH radical removal rate of 61.5%.