A method for surface treating animal tissue is provided by the invention. The method includes the steps of providing animal tissue having an average size of between about 0.5 inch and about 16 inches in length, introducing the animal tissue into a bath provided at a temperature of between about 80.degree. C. and about 150.degree. C. for between about 25 seconds and about 150 seconds, and recovering the animal tissue from the water bath. A pasteurization unit is provided for continuous processing of animal tissue.