The invention relates to a preparation method of
giant salamander skin collagen peptide. The method comprises the steps that
degreasing and deodorization are conducted simultaneously on a
giant salamander skin, black
skin and impure
protein are removed through alkali liquor, under the condition that the temperature ranges from 20 DEG C to 25 DEG C and the pressure ranges from 150 MPa to 300 MPa, pressure maintaining is conducted for 10-60 min, pH of the
giant salamander skin processed through ultrahigh pressure is regulated to 8-10,
alkaline protease with the weight of 2%-3% of the skin is added, at the temperature of 45-50 DEG C, continuous stirring and enzymolysis are conducted for 3-6 hours, the mixture is boiled for 1-2 min and cooled to 40 DEG C, pH of the mixture is regulated to 4-5,
activated carbon with the
mass of 1% of the mixture is added, and stirring and decoloration are conducted; under the condition that the rotating speed is 3000-4500 r / min,
centrifugation is conducted on the processed mixture for 10-15 min,
microfiltration through a filter membrane with the thickness of 0.45 micron,
ultrafiltration through an
ultrafiltration membrane with the molecular weight
cut-off of 4-5 kD and
nanofiltration through a
nanofiltration membrane with the molecular weight
cut-off of 2-3 kD are conducted on the mixture in sequence to obtain filter liquor, the filter liquor is concentrated to be one half of an original sample, and the concentrated liquor is freeze-dried and smashed to obtain giant salamander skin collagen
powder. According to the preparation method of the giant salamander skin
collagen peptide, the molecular weight of the
collagen peptide is small, and over 90% of the molecular weight is smaller than 1000 Dalton.