Inactivation of Clostridium botulinum nonproteolytic type B spores by high pressure processing at moderate to elevated high temperatures

The effect of high pressure and high temperature treatments at various process times on the inactivation of spores of Clostridium botulinum nonproteolytic type B strains, 2-B, 17-B, KA-P8-B, and KAP9-B, suspended in phosphate buffer (0.067M, pH7.0) and a crabmeat blend was investigated. Spores of KAP8-B were less resistant to high pressure treatment than the spores of 2-B, 17-13, and KAP9-B in both phosphate buffer and crabmeat blend. No survivors of initial counts (> 4.3 logunits) of KAP8-B spores were detected in these menstura after processing at 827MPa and 60 degrees C for 10min. The amount of inactivation of spores of 2-B, 17-B, and KAP9-B in phosphate buffer or crabmeat blend increased with the increase in processing time from 10 to 30min at 827MPa and 75 degrees C. Similar inactivation patterns were observed for these spores in both phosphate buffer and crabmeat blend. A reduction of > 6-logunits of 2-B, 17-B, and KAP9-B spores in phosphate buffer and crabmeat blend was observed at 827MPa and 75 degrees C for a processing time of between 20 and 30min. Crabmeat blend as a suspension menstrum provided no protection against inactivation of spores of 2-B, 17-B, and KAP9-B by high pressure processing. High temperature (> 95 degrees C) and lower pressure (620MPa) treatments for up to 10min were also found to inactivate 17-B spores in phosphate buffer. Spores of nonproteolytic type B strains, 2-B, 17-B, KAP8-B, and KAP9-B in phosphate buffer and crabmeat blend can be inactivated by a combination of high pressure and temperature treatments. (c) 2006 Elsevier Ltd. All rights reserved.