Study on effect of temperature on inactivation of Salmonella typhimurium by thermosonication

Inactivation of Salmonella typhimurium by mild heat and thermosonication at 32 ~52℃,especially the effect of temperature on inactivation were investigated. Results showed that it did not meet safety standards as suspension exposed to mild heat at 32 ~ 52 ℃, while the log- reduction of S. typhimurium was significantly enhanced by thermosonication at the same temperature. The inactivation of S. typhimurium reaching the level of non- detectable limit were achieved when suspension were under 190 W for 40 min and under 380, 570 W for 30 min at 52 ℃, respectively. Mild heat exerted minimal inactivation effects on S. typhimurium during thermosonication treatment at lower temperature(32~47℃),and ultrasound was dominant. At lethal temperature of 52℃,the synergistic effects of ultrasound and mild heat existed,which enhanced inactivation efficacy and rates.