Rapid hot dog surface pasteurization using cycles of vacuum and steam to kill Listeria innocua

The vacuum/steam/vacuum surface pasteurization process was applied to hot dogs inoculated on the surface with non-pathogenic Listeria innocua. Using the optimum conditions previously found for processing chicken carcasses as a starting point, optimum process conditions were determined for a hot dog treatment compatible with current process line speed. Cycling the treatment significantly improved the microbiological kill. At the optimum conditions of steam time of 0.3 s at 138 degrees C (two cycles), a bacteria kill >3 log CFU/ml was attained. Pasteurization, frequently considered to be a kill of >5 log CFU/ml, was reached by increasing the number of cycles to three. The surface pasteurization process should ensure that hot dogs reaching the consumer are free of Listeria.