15D-15 |
Cetylpyridinium chloride for control of Escherichia coli 0157:H7 on the surfaces of chopped lettuce |
M. E. JANES1, B. Lungu2, K. C. Wiggins2, and M. G. Johnson2. (1) Food Science, Univeristy of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72764, (2) Food Science, University of Arkansas, 2650 N. Young Ave., Faytteville, AR 72704 There is a growing concern for the potential health risk associated with consumption of minimally processed raw produce contaminated with enterohemorrhagic Esherichia coli 0157:H7 (EHEC). New rinsing solutions need to be developed to control this pathogen on raw fresh produce. Our study was conducted to determine the concentrations of cetylpyridinium chloride (CPC) in combination with pH that will lead to effective removal/destruction of EHEC from the surfaces of chopped lettuce and if biofilm formation by EHEC reduces the effectiveness of CPC. Chopped lettuce samples (25 g) were inoculated with 1 ml of decimally diluted 16 h broth cultures of EHEC for 1 min to yield about 6.6 log CFU/g. The lettuce samples were treated with different concentrations (0.05, 0.1 0.2, 0.4, 0.6, 0.8, and 1%) and pH (3.0 to 9.0) solutions of CPC. Lettuce samples were rinsed in the CPC solutions for 1 min, rinsed with water for 1 min, and then CFU/g of EHEC were determined. Alternatively, EHEC cells were inoculated onto chopped lettuce and allowed to grow at 25°ĘC for 0 to 4 days or at 8°ĘC for 0 to 8 days before rinsing with CPC as above. CPC at 0.05% at a pH of 6 or 7 reduced EHEC counts by 2.0 log CFU/g while the other CPC-pH solutions caused only about 1.5 log CFU/g reductions. EHEC was reduced to non-detectable levels with 0.8% to 1.0% of CPC. A 0.05% CPC treatment gave significant reductions of pre-adapted EHEC counts at both 25 and 8°ĘC compared to controls, about 2 logs at 25°ĘC and 2 to 3 logs at 8°ĘC over 4 to 8 days. Our results suggest that the use of a CPC rinsing solution may provide raw produce processors with a control measure to help reduce EHEC on the surfaces of chopped lettuce.
Session 15D, Food Microbiology: Fruits and vegetables
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