91-5 |
Effectiveness of acidified sodium chlorite in reducing Escherichia coli O157:H7 and Staphylococcus aureus on Beef Briskets |
M. N. HAJMEER1, J. L. Marsden2, D. Y. C. Fung2, G. A. Milliken3, and G. K. Kemp4. (1) Dept. of Population Health & Reproduction, Univ. of California, Davis, School of Veterinary Medicine, 1 Shields Ave., Davis, CA 95616, (2) Dept. of Animal Sciences & Industry, Kansas State Univ., 264 Weber Hall, Manhattan, KS 66506, (3) Dept. of Statistics, Kansas State Univ., 101 Dickens, Manhattan, KS 66506, (4) Alcide Corp., 8561 154th Ave. N.E., Redmond, WA 98052 Antimicrobial decontamination methods are valuable techniques for reducing potential foodborne pathogens on carcasses and meat products. This study evaluated the effectiveness of acidified sodium chlorite (ASC) and sodium chloride (NaCl) in reducing Escherichia coli O157:H7 and Staphylococcus aureus on fresh beef briskets. Meat samples (n=78; 26 per replication), each ~3.81´5.08´2.53cm, were randomly separated into two groups; one inoculated with a cocktail of 5 strains of E. coli O157:H7 and the other with 5 strains of S. aureus (~5 log10 CFU/cm2). Inoculated samples were rinsed with 0.1% ASC, 25% NaCl, or plain tap water (WW) using an automated spray washer at 4 exposure times (10, 15, 30, and 60 sec) delivering 2.3L of solution per min at a pressure of 419kPa. Control samples (NT) also were included. Following each treatment, microbial reductions were determined by plating E. coli O157:H7 samples on Tryptic Soy agar (TSA), MacConkey Sorbitol agar (MSA), and a combination of TSA/MSA medium. S. aureus samples were plated on TSA, Baired-Parker agar (BP), and TSA/BP combination. Plates were incubated at 35 ēC for 24h and enumerated. Statistically, it was found that WW, NaCl, and ASC reduced (p<0.05) E. coli O157:H7 compared to the NT for all exposure times and media type. Increasing WW or NaCl exposure time did not improve removal of E. coli O157:H7, however, extended exposure to ASC increased reduction. For S. aureus, WW did not reduce counts from NT for all times and media types (p<0.05). NaCl was effective only for a 60 sec exposure time, and ASC reduced counts below NT for all spray times and with all media types (p<0.05). Generally, ASC outperformed both WW and NaCl as a decontamination agent for E. coli O157:H7 and S. aureus.
Session 91, Acidified sodium chlorite - an antimicrobial intervention for the food industry
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