METHOD FOR SEPARATING KERATINOUS PROTEINS FROM MATERIALS

摘要

A process for separating keratinous proteins from a keratin-containing material, the process comprising the steps of: subjecting the keratin-containing material to reduction in a liquid medium to solubilise the keratinous proteins under conditions that minimise hydrolysis of the keratinous proteins, to yield a solution of keratinous proteins and undissolved solids; subjecting the solution of keratinous proteins to peroxide oxidation, without any intervening keratin precipitation step; and separating the solution of keratinous proteins from the undissolved solids prior to, at the same time as, or following the oxidation step. Preferred conditions for performing the reduction step involve contacting the keratin-containing material with a solution of an alkali metal sulfide reducing agent at a temperature of between 25 C and 50 C for a time of between 30 and 90 minutes, assuming atmospheric pressure. The peroxide oxidation is suitably carried out within not more than 4 hours after the reduction step, and involves reducing the pH of the solution to a level not less than pH 10, although pH 11.3 is most preferred. The product is demonstrated to have a principal fraction that has a molecular weight above 10 kDa, reflecting that the disulfide bonds in the keratinous proteins are broken without hydrolysis of the proteins.