Inactivation of Clostridium botulinum type A spores by high-pressure processing at elevated temperatures.
The effects of high-pressure treatments at various temperature-time combinations on the inactivation of spores of Clostridium botulinum type A strains 62-A and BS-A in phosphate buffer (0.067 M, pH 7.0) and in a crabmeat blend were investigated. The log unit reduction of strain 62-A spores increased significantly as the processing pressure increased from 417 to 827 MPa (from 60,000 to 120,000 lb/in2) at 75 degrees C. The reduction of BS-A and 62-A spores in either medium increased as processing temperatures increased from 60 to 75 degrees C and processing times increased from 5 to 15 or 20 min at a maximum pressure of 827 MPa. Approximately 2- and 3-log reductions of BS-A and 62-A spores, respectively, in phosphate buffer were obtained at the maximum pressure-maximum temperature combination of 827 MPa and 75 degrees C for a processing time of 20 min. Processing for 15 min at the maximum pressure-maximum temperature combination resulted in maximum reductions of 3.2 and 2.7 log units for BS-A and 62-A spores, respectively, in the crabmeat blend. Results obtained in this study indicate that the crabmeat blend did not protect BS-A and 62-A spores against inactivation by high-pressure processing.
Reddy
N R
NR
U.S. Food and Drug Administration, National Center for Food Safety and Technology, 6502 South Archer Road, Summit-Argo, Illinois 60501, USA. rukma.reddy@cfsan.fda.gov
Solomon
H M
HM
Tetzloff
R C
RC
Rhodehamel
E J
EJ
D000818:Animals; D003386:Brachyura; D003014:Clostridium botulinum / Q000254:growth & development / Q000502:physiology*; D003257:Consumer Product Safety; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D006358:Hot Temperature; D011312:Pressure; D017747:Seafood / Q000382:microbiology*; D013171:Spores, Bacterial / Q000254:growth & development