Evaluation of thermal inactivation parameters of Salmonella in whole wheat multigrain bread.

This study was conducted to validate a simulated commercial whole wheat multigrain bread baking process at 375 °F (190.6 °C) oven temperature for 35 min to inactivate Salmonella , and to determine the thermal inactivation parameters of a 7-serovar Salmonella cocktail in whole wheat multigrain bread dough. A ≥5-log CFU/g reduction in Salmonella population was achieved by 15 min, and no viable Salmonella was detected after enrichment plating by 16 min. The a w of the bread crumb (0.96) after baking and 60 min of cooling was similar to that of pre-baked bread dough, whereas the a w of bread crust decreased to 0.81 at the end of baking and cooling. The D-values of the Salmonella cocktail in bread dough were 59.6, 20.0 and 9.7 min at 50, 52 and 55 °C, respectively; and the z -value was 6.5 °C. • This study validated that baking whole wheat multigrain bread at >190 °C oven temperature for at least 16 min will control the risk of Salmonella. • Bread water activity profiles on the surface and inside varied during the baking process. • D and z values of Salmonella could provide the basic information on the thermal resistance at the start of the baking process. [ABSTRACT FROM AUTHOR]