Survival of Salmonella senftenberg 775 W to current liquid whole egg pasteurization treatments

摘要

The effect of heat shocks at constant temperature (isothermal heat shocks) or at constantly raising temperatures (anisothermal heat shocks) on the thermotolerance in liquid whole egg of the heat-resistant strain Salmonella senftenberg 775 W was investigated. The thermotolerance of Salmonella senftenberg 775 W increased with isothermal shock temperature. The D_(63℃) in liquid whole egg raised from 1.2 to 3.1 min after 1h of isothermal heat shock at 54℃. Anisothermal heating lag phases also increased the thermotolerance of S. senftenberg 775 W in liquid whole egg to a higher extent, the higher the final temperature reached. Heating rate did not affect the heat resistance of S. senftenberg along the isothermal phase. Industrial pasteurization treatment for liquid whole egg at 60℃ for 3.5 min, 64℃ for 2.5 min and 70℃ for l.5 min would only attain <1, <2 and <4 log cycles reduction, respectively, in the population of this heat-resistant Salmonella strain.