Effect of Packaging Systems and Pressure Fluids on Inactivation of Clostridium botulinum Spores by Combined High Pressure and Thermal Processing

Several studies have been published on the inactivation of bacterial spores by using high pressure processing in combination with heat. None of the studies investigated the effect of the packaging system or the pressurizing fluid on spore inactivation. The objective of this study was to select and validate an appropriate packaging system and pressure transfer fluid for inactivation of Clostridium botulinum spores by using high pressure processing in combination with thermal processing. Inactivation of spores packaged in three packaging systems (plastic pouches, cryovials, and transfer pipettes) was measured in two pressure test systems (laboratory-scale and pilot-scale) at 700 MPa and >105 degree C. Total destruction (>6.6-log reduction) of the spores packaged in the graduated tube part of transfer pipettes was obtained after processing for up to 10 min at 118 degree C and 700 MPa in both pressure test systems, compared with the spores packaged either in plastic pouches or cryovials. Reduction of spores packaged in plastic pouches was lowest (