Validation of a simulated commercial traditional crust pepperoni pizza baking process and thermal inactivation parameters of a 3-serovar Salmonella inoculum in pizza dough

The objective of this study was to validate a simulated commercial baking process for traditional crust pepperoni pizza to inactivate Salmonella when contamination was introduced through inoculated flour and pepperoni slices. The unbleached flour and pepperoni slices were inoculated (separate studies) with a 3-serovar Salmonella cocktail and dried back to their respective pre-inoculation water activity level to achieve 6.14 and 6.84 log CFU/g, respectively. The inoculated traditional crust pizza was baked at 260°C (500 °F) for 12 min followed by 15 min of ambient cooling. In both cases, a >6 log CFU/g reduction in Salmonella population was achieved by the first 8 min of baking. The pH (5.23–5.25) and water activity (0.958 ± 0.001–0.938 ± 0.005) of the pizza in this study did not change significantly. The D-values of 3-serovar Salmonella cocktail in traditional crust pepperoni pizza dough were 23.2 ± 1.82, 7.50 ± 0.32, and 2.0 ± 0.15 min at 56°C, 59°C, and 62°C, respectively, with a z-value of 5.7°C. The study validated that traditional crust pepperoni pizzas when baked at 260°C (500 °F) for at least 12 min will reduce Salmonella populations by ≥5 log CFU/g if prebaking contamination occurs via flour and/ or pepperoni.