Bacteriological Quality of Hot‐Boned Primal Cuts from Electrically Stimulated Beef Carcasses

The objective of this study was to determine bacterial numbers on primal cuts from hot and cold‐boned beef carcass sides, and to determine the influence of U.S. Grade and electrical stimulation of the cracass on the incidence of bacteria. Ten boneless primal cuts were removed from each of ten beef carcass sides either 1 or 48 hr after animal slaughter. The primal cuts included the brisket, clod, chuck roll, ribeye, striploin, tenderloin, top sirloin, knuckle, inside round, and gooseneck. The primal cuts were sampled for aerobic (APC 5°C, 20°, 35°C) and coliform bacteria at time of removal from the side and after 20 days' vacuum packaged storage at 2°C. The psychrotrophic bacteria enumerated at 5°C were more numerous (P<0.05) on the primals from the hot‐boned sides than from the cold‐boned sides before storage, but not after 20 days' storage at 2°C. The mesotrophic and psychrotrophic bacteria enumerated at 20°C, and the mesotrophic bacteria enumerated at 35°C, were more numerous on the hot‐boned primals than on the cold boned primals both before and after storage (P<0.05). The magnitude of the difference, on some primals, was greater than one logarithm. Coliform bacteria were not influenced (P<0.05) by hot boning before or after storage. Storage of the primal cuts resulted in some profuse growth of the coliforms. Neither U.S. grade nor electrical stimulation had any apparent influence on the incidence or growth of aerobic bacteria.