| 摘要 |
A particulate proteinaceous product is prepared from waste raw protein-containing animal parts with a method and an apparatus having a mulling stage wherein the raw animal parts are reduced to a ground condition; a hydrolyzing stage wherein proteins in the ground animal parts are hydrolyzed to a predetermined extent to form an aqueous suspension, using either endogenous or supplementary proteolytic enzymes, and subsequently heated to inactivate the enzymes and convert fats in the suspension to oils; a screening stage wherein non-digestible solids are removed from the suspension; a concentration stage wherein extraneous oil is added to the suspension, the suspension is pasteurized, and a large portion of the water is removed therefrom; and an oil-separation stage wherein sufficient oil is removed to form the product. A portion of the removed oil is routed back to the beginning of the concentration stage as extraneous oil added to the suspension to permit sufficient water to be removed from the suspension without forming a stiff, unprocessable mass. The method is distinctive in that it produces a dry, flaky product without the use of a conventional dryer. The method is also distinctive for its substantial resistance to equipment clogging. The proteinaceous product is dry to the touch, is compressible into pellets or cakes, and contains about 45 to 65 w/w percent partially hydrolyzed, non-denatured animal protein, about 20 to 35 w/w percent oil derived from the animal parts, about 10 to 15 w/w percent moisture, and about 0 to 7 w/w percent ash. The product also has reduced objectionable odor, reduced propensity to oxidize, and high nutritional value.
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