Reduction of Escherichia coli O157:H7 and Salmonella Typhimurium on Beef Carcass Surfaces Using Acidified Sodium Chlorite

Abstract

The efficacy of a phosphoric acid-activated acidified sodium chloride (PASC) spray and a citric acid-activated acidified sodium chlorite (CASC) spray applied at room temperature (22.4 to 24.7 degrees C) in combination with a water wash was compared with that of a water wash only treatment for reduction of Escherichia coli O157:H7 and Salmonella Typhimurium inoculated onto various hot-boned individual beef carcass surface regions (inside round, outside round, brisket, flank, and clod). Initial counts of 5.5 and 5.4 log CFU/cm2 were obtained after inoculation with E. coli O157:H7 and Salmonella Typhimurium, respectively. Initial numbers for both pathogens were reduced by 3.8 to 3.9 log cycles by water wash followed by PASC spray and by 4.5 to 4.6 log cycles by water wash followed by CASC spray. The sprays consisted of applying 140 ml of the appropriate sanitizing solution for 10 s at 69 kPa. Corresponding reduction values obtained by water wash alone were 2.3 log. The performance of CASC appeared to be consistently better than that of PASC. In general, no effect of the carcass surface region was observed on the log reductions for either pathogen, except for the inside round, which consistently had lower reductions. Both PASC and CASC were capable of effectively reducing pathogens spread to areas beyond the initial contaminated area of the cuts to levels close to or below the counting method detection limit (0.5 log CFU/cm2). However, 30 to 50% of the carcasses treated by these antimicrobial solutions still yielded countable colonies. Results of this study indicate that acidified sodium chlorite sprays are effective for decontaminating beef carcass surfaces.

Development and Evaluation of an On-Line Hide Decontamination Procedure for Use in a Commercial Beef Processing Plant

“…Treatment of beef trim with 200 and 1,000 ppm acidified chlorine has been described (20,23). Others have reported using 1,200 ppm acidified chlorine to treat carcass surfaces (8). The bacterial reductions in these studies were consistently greater than 2.0 log CFU/g for E. coli and greater than 1.0 log CFU/g for APC.…”

“…Acidified chlorine was chosen because it is a commonly used sanitizing agent and antimicrobial. Used alone, acidified chlorine reduces contamination levels of beef trim and carcasses (8,20). The acidified chlorine used as a rinse in our experiments was prepared at calculated concentrations of 200 and 500 ppm.…”

Antimicrobial Activity and Stability of Weakly Acidified Chlorous Acid Water

“…This sanitizer, acidified sodium chlorite ASC; Ecolab Inc., Minnesota, USA , has been approved by the Food and Drug Administration of the United States for use on poultry, red meats, seafood, and raw agricultural commodities Anonymous, 1998;Federal Register, 1999 . ASC is a broad-spectrum antiseptic Castillo et al, 1999;Hajmeer et al, 2004 that can be easily prepared by mixing a NaClO 2 solution with organic acids that are generally recognized to be safe, such as citric acid and phosphate. Although NaClO 2 alone shows only weak antimicrobial activity at neutral or a l k a l i n e c o n d i t i o n s , u p o n s t ro n g a c i d i f i c a t i o n antimicrobial chlorite HClO 2 is generated Kobayashi et al, 1989 .…”

Application of Acidified Sodium Chlorite Prewashing Treatment to Improve the Food Hygiene of Lightly Fermented Vegetables

“…To reduce the risk of food poisoning caused by lightly fermented vegetables, effective sanitizing of the raw produce may be required. Washing raw produce with sodium-chlorinated water (NaClO) is the most commonly used method to remove pathogens from surfaces of vegetables 11 . Many experimental studies have been performed to evaluate the effectiveness of sodium chlorinated water, acidic electrolyzed water or other sanitizers for sanitation of pathogenic bacteria on the surface of vegetables 4,[27][28][29][30]32,49 .…”