89E-8 |
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M. M. SALAMEH, S. A. Ibrahim, and C. W. Seo. Food Science & Nutrition Program, North Carolina A&T State Univ., Dept. of Human Environment & Family Sciences, 171-B Carver Hall, Greensboro, NC 27411-1064 Since Escherichia coli O157:H7 was first identified as foodborne pathogen in 1982, there has been a growing demand for practical and efficient intervention method to eliminate this and other food pathogens from our food supply. The objective of this research was to determine the effectiveness of caffeine on inactivation of E. coli O157:H7 in brain heart infusion (BHI) broth. Overnight samples of five E. coli O157:H7 strains of (E0019, F4546, H1730, 944 and Cider) were used in this study. These strains were individually inoculated at an initial inoculum level of 2 log CFU/ml into BHI broth containing caffeine with different concentrations (0.00, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, and 2.00%) of caffeine. Samples were then incubated at 37o C for 24 h. Bacterial growth was monitored at different time intervals by measuring turbidity at 610nm using a spectrophotometer. Results revealed that the addition of caffeine inhibited the growth of E. coli O157:H7. Significant growth inhibition was observed with concentration levels 0.50%. Further concentrations of caffeine continue to cause further growth reduction of E. coli. The pattern of growth inhibition by caffeine level (0 to 2%) was similar among all strains of E. coli O157:H7 used in this study. When caffeine concentrations increased in broth, growth inhibition was significantly increased among all tested strains (P < 0.0001). These results indicate that caffeine has the potential as an antimicrobial agent for the treatment of E. coli O157:H7 infection and should be investigated further as a food additive to increase biosafety of consumable food products.
Session 89E, Food Microbiology: Pathogens
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |