18D-20 |
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A. MOHAN, Department of Food Science, The Pennsylvania State Univesity, 119 Borland Laboratory, University Park, PA 16802 and C. E. Sizer, III, National Center for Food Safety & Technology, Illinois Institute of Technology, IIT Moffett Campus, 6502 S. Archer Rd., Summit-Argo, IL 60501-1923. JUSTIFICATION Antimicrobials play a major role in effective control of food borne pathogens and spoilage microorganisms. They are generally used to inactivate target microorganisms on the food contact surfaces, food service equipment and food packaging. Some species of bacteria are capable of adapting to hostile conditions by forming thick outer films and/or chemically resistant spore coat. OBJECTIVE Our study explored the microbial inactivation and mechanism of radical induced inactivation of resistant bacterial spores using electron spin resonance spectroscopy. The objective of this study was to determine the kinetics for the inactivation and mechanism of surface-active radicals involved in the inactivation by using electron spin resonance spectroscopy. METHOD Inactivation of Bacillus subtilis spores (ATCC 9372) was studied using peroxyacetic acid, with octanoic acid sanitizer, under a range of conditions between 50 to 700C temperature at different time intervals. Kinetic tests were performed to determine the effects of peroxyacetic acid, on B. subtilis spores under dry and wet conditions. Peroxycetic acid and other component ingredients were used for capturing the active radicals using a spin trap. RESULTS Studies showed 4-5 logs of reduction at 1% concentration. At 2% concentration of peroxyacetic acid, at 50° C temperature, complete inactivation was achieved. In order to understand the chemical reactions involved in spore inactivation, electron spin resonance was used to determine the free radicals generated by the sporicidal agent. SIGNIFICANCE This study revealed that peroxyacetic acid at 2% concentration level generates a combination of hydroxyl, hydroperoxyl and super oxide radicals. These reactive species have been shown to be very effective biocides for bacterial spores. This information has practical application in the food/dairy industry for sanitation and disinfection. Our study suggests a major application for the development of antimicrobials using peracetic acid in combination with hydrogen peroxide and surfactants, which could be a potent lethal agent for most forms of bacterial spores.
Session 18D, Food Microbiology: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |