Method of producing stabilized bone

Abstract

A continuous process of preparing low fat stabilized bone particularly suited for producing high quality gelatin from trimmed raw bone which is preferably crushed in a pre-hogger and fed continuously to preferably a screw type press mounted within a cage having a choke and perforations in the wall of the cage through which soft non-bone material is extruded. The pressed bone which is recovered separately from the soft non-bone material has a substantially reduced content of fat and meat tissue without heating while in contact with liquid fat. The pressed bone is heated in an oven dryer to a temperature up to 250.degree. F. (121.degree. C.) which crisps the fat and meat tissue adhering to the pieces of bone so that the crisp fat and meat tissue is readily separated from the bone during the heating, tumbling and screening thereof. The baked crushed bone preferably after cooling is subjected to a dry separation treatment by first passing the heated crushed bone over a sizing screen which removes particles over and under a selected particle size range. The material having the selected particle size range is then continuously subjected to gravity separation by depositing the selected material on a vibrating screen air table on which the high density clean stabilized bone particles climb to the upper end of the air table and are collected as final product separately from the low density fat and meat tissue particles which are concentrated at the lower end of the air table.