Sporicidal Properties of Chlorine Compounds: Applicability to Cooling Water for Canned Foods1,2

Abstract

Sporicidal effects of chlorine compounds as measured by many authors are reviewed. Since spore destruction rates and hypochlorous acid concentration appear to be related, the data from the several reports were recalculated in terms of time required for a 90% reduction in spores as a function of hypochlorous acid concentration. From these data a single graph was prepared. Results of the analysis indicate that Bacillus spores are more resistant to chlorine than Clostridium spores. The sporicidal effect of chlorine solutions increases with (a) an increase in free available chlorine, (b) a decrease in pH, and (c) an increase in temperature. Numbers of Clostridium botulinum and other spore-forming organisms in canning plant cooling water will depend on water quality factors such as the quantity of soil and organic matter, pH, temperature, and chlorine level. Control of these variables to desired levels in cooling water will reduce the probability of post-process infection of low-acid canned foods.