Abstract
Attempts were made to isolate native acid-soluble collagen from fish muscle by removing selectively non-collagenous proteins with a dilute NaOH solution. The preliminary extraction with 0.01 and 0.05N NaOH did not remove satisfactorily non-collagenous proteins from carp muscle, whereas the preliminary extraction with 0.5 and 1.0N NaOH modified the polypeptide chains of collagen, thus increasing the solubility of collagen. On the other hand, the preliminary extraction with 0.1N NaOH was found to remove non-collagenous proteins most effectively without any modification of collagen and also to exclude the effect of endogenous proteases on collagen during preparation.
On the basis of these results, a method involving the preliminary extraction with 0.1N NaOH was proposed for isolating native acid-soluble collagen from fish muscle.
