The Effect of Water Activity on the Heat Resistance of Heat Sensitive and Heat Resistant Strains of Salmonellae

Abstract

Summary. A strain of Salmonella senftenberg and a strain of Salm. bedford have been found with D 60° values similar to that of the classical heat resistant salmonella, Salm. senftenberg strain 775W. The resistances of the two heat resistant serotypes and two heat sensitive strains of these serotypes was determined in heart infusion broth containing increasing amounts of sucrose, sodium chloride or glycerol. The observed changes in heat resistance could not be related directly to the a w of the heating menstruum. It is impossible to predict from such studies the heat resistance of salmonellae in foods of low a w .