Gelatin extraction

#This invention relates to improvement in the conditioning of collagen for gelatin extraction.

#Collagen is a major protein constituent of connective tissue in the vertebrate as well as invertebrate animal kingdoms. In practice, meat industry materials rich in collagen such as bone, and skin (notably pork skin) are the starting materials for the production of collagen or collagen derived products like gelatin.

#Gelatin is found in two types: type A gelatin prepared by acid pretreatment of a collagenous raw material, preferably porkskin, and type B gelatin prepared by alkaline pretreatment of a collagenous raw material, preferably dry bone or dehaired hides.

#A preferred embodiment of collagen conditioning according to the invention comprises use of trypsin as the proteolytic enzyme.

#Another preferred embodiment of collagen conditioning according to the invention comprises use of proteinases produced microbially from microorganisms of the genue Bacillus as the proteolytic enzyme, and notably from B. subtillus and from B. licheniformis.

#Another preferred embodiment of collagen conditioning according to the invention comprises use of alkaline resistant proteinases produced according to practice of British Pat. No. 1,243,784 (which corresponds to U.S. Pat. No. 3,723,250). The hides employed for production of gelatin may have already been limed, as for example for dehairing purposes, and are at a rather alkaline pH value. Since the alkaline resistant proteinases are active at the pH values of the liming conditions employed for dehairing (see U.S. Pat. No. 3,840,433), these enzymes offer the special advantage that the pH of the float for such hides need not be adjusted.