89A-19 |
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T. M. DUPARD, M. E. Janes, and J. W. Bell. Dept. of Food Science, Louisiana State Univ. Agricultural Center, 111 Food Science Bldg., Baton Rouge, LA 70803-4200 Listeria monocytogenes (Lm) is currently a major pathogen of concern for the seafood industry. Seafood products that have contributed Lm outbreaks include cold-smoked trout, shrimp, and smoked mussels. Cetylpyridinium Chloride (CPC) has been shown to have antimicrobial effects in decontaminating raw produce and poultry. Our study was conducted to determine the concentration of CPC that will lead to effective removal/destruction of Lm from the surfaces of shelled raw and cooked shrimp. Raw and cooked shrimp with shells (5 g) were dipped into a 24h culture of Lm (decimally diluted in PBS) for 1 min to yield about 7.0 Log CFU/g then placed under a laminar flow hood for 1 hour to allow the bacteria to attach. The shrimp samples were treated with different concentrations of CPC (0.05, 0.1, 0.2, 0.4, 0.6, 0.8, or 1.0%) solutions for 1 min, with or without a water rinse for 1 min, and then CFU/g of Lm determined on Oxford selective media. All CPC concentrations with a water rinse reduced Lm counts on the surface of cooked shrimp by about 2.5 Log CFU/g. Conversely, without a water rinse Lm counts on the surface of cooked shrimp were reduced 3 Log CFU/g with 0.1, 0.2 or 0.4% CPC, 5 Log CFU/g with 0.6% CPC, 6 Log CFU/g with 0.8% CPC and 7.0 Log CFU/g with 1.0% CPC. CPC at 0.05, 0.1, 0.2, or 0.4% without a water rinse and all CPC concentrations tested with a water rinse reduced Lm counts on the surface of raw shrimp by about 2.5 Log CFU/g. At 0.6, 0.8, 1.0% CPC without a water rinse Lm counts were reduced on the surface of raw shrimp by 3.0 Log CFU/g. These results indicate the potential of cetylpyridinium chloride as a washing solution to eliminate or reduce Lm on the surfaces of shrimp.
Session 89A, Aquatic Food Products: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |