91E-2 |
Inactivation of Clostridium botulinum nonproteolytic type B spores in a model buffer or food system by high pressure processing |
N. R. REDDY1, H. M. Solomon2, R. C. Tetzloff3, V. M. Balasubramaniam3, and E. J. Rhodehamel4. (1) National Center for Food Safety and Technology/Food and Drug Adminstration, 6502 S. Archer Road, Summit-Argo, IL 60501, (2) Food and Drug Administration, 200 C Street, SW, Washington, DC 20204, (3) National Center for Food Safety and Technology/illinois Institute of Technology, 6502 S. Archer Road, Summit-Argo, IL 60501, (4) Cryovac/Sealed Air Corp., 100 Rogers Bridge Road, Bldg.A, Duncan, SC 29334 Use of high pressure processing (HPP) to inactivate microorganisms in foods and food ingredients without a decrease in product quality has received renewed interest. There is very little information available on the resistance of C. botulinum spores subjected to HPP treatments. Effect of HPP on inactivation of nonproteolytic type B C. botulinum spores in model phosphate buffer and crabmeat blend was studied. Nine mL of phosphate buffer (0.067M, pH7.0) or crabmeat blend (1:1 with sterile water) and 1.0mL (1.0 x106-7 spores/mL) of spores of individual strains of C. botulinum (2-B, 17-B, KAP8-B and KAP9-B) were placed in sterile, high barrier film pouches and heat sealed. Two of these pouches were heat sealed inside a large high barrier film bag. The packages were subjected to different temperatures (35 to 75oC) at a pressure of 827 MPa for up to 30 min using a Quintus Model QFP-6 High Pressure Food Processor. Surviving viable spores in processed samples were enumerated by 5-tube Most Probable Number (MPN) method after incubation at 26oC for 3 days. End point toxin was determined and confirmed. Tubes with no growth were covered with sterile vasper and mineral oil and incubated at 22oC for 4 months. Spores of KAP8-B were less resistant to HPP treatment than the spores of 2-B, 17-B, and KAP9-B in phosphate buffer and crabmeat blend. Complete inactivation (over 4-log reduction) of spores of KAP8-B in both systems was obtained by processing at 827 MPa and 60oC for 10 min. Inactivation of spores of 2-B, 17-B, and KAP9-B in either systems increased with processing time (from 10 to 30 min) at 827 MPa and 75oC. An increase of processing time from 15 to 20 min at these high pressure/temperature levels resulted in more than 5-log reduction of 2-B, 17-B, and KAP9-B spores in either systems. HPP technology can be used for inactivation of spores of nonproteolytic type B in phosphate buffer system or crabmeat blend.
Session 91E, Nonthermal Processing: Nonthermal processing of foods
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