The invention belongs to the field of
food biotechnology, and particularly relates to a method for preparing I type collagen and V type collagen. The method comprises main steps of cleaning, draining off,
cutting up and
drying fishskin with scale and
subcutaneous tissue removed, smashing, then
steeping in 0.1M NaOH solution, stirring, then centrifuging to obtain precipitate, washing to be almost neutral, then putting in precooling water, adding
acetic acid and pepsase and stirring, centrifuging to obtain the supernate, adding NaCl, then
salting out, centrifuging, dissolving the precipitate into
Tris-HCl
buffer solution containing NaCl, centrifuging, then obtaining supernate, adding NaCl to salt out, centrifuging, then collecting precipitate and supernate respectively, dissolving, dialyzing, freeze-
drying the precipitate so as to obtain the I type collagen, adding NaCl into the supernate, then
salting out, centrifuging, then taking the precipitate, dissolving, dialyzing and freeze-
drying so as to obtain the V type collagen, wherein all the steps are carried out at 4DEG C. The I type collagen and V type collagen are prepared through fractional
salting out; the method is simple, and has strong
operability, low cost and high efficiency.