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P2-204 Pressure-assisted Thermal D-values of Nonproteolytic Clostridium botulinum Types B and F

Monday, July 27, 2015
Exhibit Hall (Oregon Convention Center)
Travis Morrissey , U.S. Food and Drug Administration , Bedford Park , IL
Viviana Loeza , Institute for Food Safety and Health , Bedford Park , IL
Lindsay Halik , Institute for Food Safety and Health , Bedford Park , IL
Eduardo Patazca , Illinois Institute of Technol./IFSH , Bedford Park , IL
Rukma Reddy , U.S. Food and Drug Administration , Bedford Park , IL
Guy Skinner , U.S. Food and Drug Administration , Bedford Park , IL
Kristin Schill , U. S. Food and Drug Administration , Bedford Park , IL
John Larkin , Food Protection and Defense Institute , St. Paul , MN
Introduction: The impact of High Pressure Processing (HPP) on the inactivation of non-proteolytic spores of Clostridium botulinum is important in extended shelf life chilled low-acid foods. Three most resistant strains (Ham-B, Kap 9-B, and 610-F) were selected after screening 17 non-proteolytic of C. botulinum strains (8 type B, 7 type E, and 2 type F) for inactivation kinetics.

Purpose: Study the inactivation kinetics of resistant non-proteolytic C. botulinum type B and F strains (Ham-B, Kap 9-B, and 610-F) spores suspended ACES buffer (0.05 M, pH 7.0) using high pressure processing.

Methods: Spores of non-proteolytic C. botulinum strains, Ham-B, Kap 9-B and 610-F were prepared using biphasic media and diluted in ACES buffer (0.05 M, pH 7) to 105-106 CFU/ml and placed into a modified sterile transfer pipette, heat-sealed and subjected to a combination of temperatures (80-91°C) and high pressures (600-750 MPa) in a laboratory- scale high pressure test system. Survivors in the processed samples were determined by 5-tube MPN method using TPGY broth after incubation for 3 months.

Results: Pressure-assisted thermal D-values (min) of Ham-B, Kap 9-B, and 610-F decreased as the process temperature increased from 80 to 91°C with any pressure combination. Highest log reductions (> 5.0) of spores of Ham-B, Kap 9-B, and 610-F occurred at the highest temperature and pressure combination (91°C and 750 MPa) tested. Pressure-assisted thermal D-values at 91°C and 600 MPa for Ham-B, Kap 9-B, and 610-F were 2.39, 2.96, and 2.45 min, respectively. D-values of Ham-B, Kap 9-B, and 610-F decreased to < 1.0 min as the pressure increased from 600 to 750 MPa at this temperature.

Significance: The results indicate that high pressure processing in combination with high temperature can be used to inactivate C. botulinum spores in less time than thermal processing alone.

Back to: Poster Session 2 – Laboratory and Detection Methods; Meat, Poultry and Eggs; Dairy and Beverages; Food Law and Regulation; General Microbiology; Modeling and Risk Assessment
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