It is well known that even the variation of only 1 °C can be very important for the kinetics of destruction of microorganisms. For example, temperature increase from 50 °C to 55 °C of pork meat results in a reduction of more than 80% of the time needed for elimination of 6 log cycles of Bacillus cereus (Byrne, Dunne, & Bolton, 2006). In our experiments, the use of ultrasound allowed a temperature rise of 3.9 °C and 2.5 °C in the outer and inner portion of sausages, respectively, and could explain at least partially the effect of US on the bacteria. The effect of ultrasound could be also be explained by the evidences that some bacteria were not killed, but sub lethally injured by the application of US leading to weakened cells that are less susceptible to grow