Development of an effective process from livestock and for utilization of collagen fish waste

A procedure for the extraction of protein and production of peptides by enzymic hydrolysis from bone and skin wastes containing collagen was developed. Fat and inorganic components were first removed in a pretreatment step and a high molecular weight protein extracted under acidic conditions (pH 3) using a 1 h reaction time at 60 degreesC. The molecular weight of extract from pig skin was greater than 100 kDa. The extract had a high water retention capacity, was beneficial for repair of rough skin, had no odor problem and was demonstrated to be safe in skin patch tests. It was thus considered acceptable for use in cosmetic materials. Pretreated fish bone and pig skin were hydrolyzed with a commercial enzyme. The hydrolysates had a high anti-radical activity (IPOX50, 0.18 and 0.45 mg ml(-1)) and a high potential for decreasing blood pressure (IC50, 0.16 and 0.41 mg ml(-1)), suggesting the hydrolysates could be a useful additive in food materials. (C) 2002 Published by Elsevier Science Ltd.