Heating process are widely used in the food industry to enhance product quality and safety. Destruction of Salmonella by heat, it should be explained that as they are heated and a temperature is reached at which they are destroyed, they are not all destroyed at once.
Large numbers are destroyed when the heat is first applied, but the death rate quickly drops.
For instance , if at 48.9 degree C, 90% of the organisms would be destroyed in a period of 5 minutes, it would take 10 minutes to kill 99% of the organisms, 15 minutes to kill 99.9% of the organisms and so on.
Salmonella is not a spore forming organism. It is not, therefore, a heating resistant organism; pasteurization and equivalent heat treatments will destroy the organism under normal circumstances.
It should be noted that if some of these Salmonella organisms in foods survive whatever heating they receive during coking, and the food is thereafter held at temperatures at which they will grow 6.7-43.3 degree C, especially at room temperature, the organisms may grow again to large numbers.
When heating foods, it is important that all parts of the foods satisfy this temperature time requirements.
Some types of cooking is not sufficient to destroy all Salmonella bacteria that may be present in foods. Examples of cooked foods in which these organisms may survive are scrambled, boiled, or fried eggs, meringue, turkey stiffing , oyster stew, steamed clams, and some meat dishes.
Salmonella are more heat resistant in yolk than in whole egg due to the lower pH an higher total solids content in the yolk.
Destruction of Salmonella by heat