Effects of environmental conditions on growth and survival of Salmonella in pasteurized whole egg

• We modeled survival and growth of S. Enteritidis in pasteurized whole egg (PWE).
• NaCl and temperature significantly influenced growth rate of S. Enteritidis in PWE.
• NaCl protected from heat inactivation in PWE over the tested range (50 °C to 58 °C).

This study investigated the influence of three parameters (time, temperature and NaCl concentration) on survival and four parameters (temperature, NaCl and lysozyme concentrations and pH) on growth of Salmonella enterica serovar Enteritidis (S. Enteritidis) in pasteurized whole egg (PWE). Doehlert uniform shell design was employed to choose conditions for trials and data was fitted to polynomial models and were presented as estimated response surfaces. A model for prediction of reduction of S. Enteritidis in PWE within temperatures between 50 and 58 °C, NaCl concentrations of 0–12%, and heating times between 30 and 210 s and a model for prediction of growth rate of S. Enteritidis in PWE in the temperature range of 1–25 °C, NaCl concentration of 0–12%, pH between 5 and 9, and lysozyme concentrations of 107–1007 U/mg proteins were developed. The maximum reduction condition was 58 °C, 0% of NaCl at a fixed heating time of 120 s, while maximum growth rate was estimated at 25 °C and 0% of NaCl. pH and lysozyme concentration were shown not to influence growth performance significantly in the range of values studied. Results inform industry of the optimal pasteurization and storage parameters for liquid whole egg.