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

Abstract

The hides of cattle are the source of Escherichia coli O157:H7 that contaminates beef carcasses during commercial beef processing. Therefore, effective interventions that reduce hide contamination should reduce subsequent carcass contamination. The first objective of this study was to identify the most effective reagents for decontamination of beef hides. Cattle hides draped over barrels were used for in vitro experiments to compare the efficacy of washes using 1.6% sodium hydroxide, 4% trisodium phosphate, 4% chlorofoam, or 4% phosphoric acid, each followed by a rinse step using either water or acidified (pH 7.0) chlorine at 200 or 500 ppm. All treatments using a water rinse reduced hide coliform counts by 1.5 to 2.5 log CFU/ 100 cm 2 . Compared with water rinses, 200 and 500 ppm acidified chlorine rinses increased efficacy by approximately 1.0 and 2.0 log CFU/100 cm 2 , respectively. Vacuuming of the treated areas to remove excess liquid improved hide cleanliness by an average of an additional 1.0 log CFU/100 cm 2 . The second objective was to evaluate the use of an on-line hide-wash cabinet that used a sodium hydroxide wash and a chlorinated (1 ppm) water rinse. Hides sampled before entering and after exiting the cabinet had aerobic plate counts and Enterobacteriaceae counts that were reduced by 2.1 and 3.4 log CFU/100 cm 2 , respectively, and the prevalence of E. coli O157 on hides was reduced from 44 to 17% when the cabinet was in use. Preevisceration carcass aerobic plate counts and Enterobacteriaceae counts were both reduced by 0.8 log CFU/100 cm 2 , and the prevalence of E. coli O157 on preevisceration carcasses was reduced from 17 to 2% when the cabinet was in use. These results support decontamination of hides as an effective means to reduce pathogen contamination of cattle carcasses during processing.Cattle hides are major sources of beef carcass contamination that occurs during processing (3,5,16). During the hide removal process, pathogens such as Escherichia coli O157:H7 and Salmonella are transferred from the hide, which carries high concentrations, to the carcass (1,3,5,16). The current hazard analysis and critical control point plans (25) implemented in most beef processing plants in the United States focus on decontamination of the carcass by a combination of intervention strategies, including steam vacuuming, acid rinses, steam, and hot water spray (11). Such antimicrobial interventions combined with strict hygiene practices have significantly improved the microbial quality of beef carcasses in processing plants (1-3, 10). However, occasional process failures result in higher levels of contamination that cannot be effectively removed with current carcass interventions.Processes that effectively clean the hides before hide removal are successful in lowering carcass microbial contamination (5, 16). In an evaluation of chemical dehairing,

Transportation and Lairage Environment Effects on Prevalence, Numbers, and Diversity of Escherichia coli O157:H7 on Hides and Carcasses of Beef Cattle at Processing

“…In a study done by , the carcass contamination rates during processing could not be accounted for by the fecal prevalence of Escherichia coli O157:H7, but could be accounted for by hide prevalence. Bosilevac et al (7,8) and Nou et al (20) extended these findings by demonstrating that antimicrobial interventions targeting cattle hides lead to drastic reductions in the rates of carcass contamination with E. coli O157:H7.Because hide is the main source of carcass contamination, it is crucial to minimize the amount of E. coli O157: H7 on cattle hides before slaughter. Cattle can shed E. coli O157:H7 in their feces at concentrations as high as 10 6 CFU/g (24).…”

“…The results of this study indicate that transport to and lairage at processing plants can lead to increases in the prevalence and degree of E. coli O157:H7 contamination on hides and the number of E. coli O157:H7 pulsed-field gel electrophoresis types associated with the animals. More study is needed to confirm the mechanism by which additional E. coli O157:H7 strains contaminate cattle hides during transport and lairage and to design interventions to prevent this contamination.Recent work has revealed that the major source of beef carcass contamination is cattle hides (4,7,8,20). In a study done by , the carcass contamination rates during processing could not be accounted for by the fecal prevalence of Escherichia coli O157:H7, but could be accounted for by hide prevalence.…”

“…Recent work has revealed that the major source of beef carcass contamination is cattle hides (4,7,8,20). In a study done by Barkocy-Gallagher et al (4), the carcass contamination rates during processing could not be accounted for by the fecal prevalence of Escherichia coli O157:H7, but could be accounted for by hide prevalence.…”

Escherichia coli verotoxigénica: modelo cuantitativo de exposición y escenarios de riesgos en canales bovinas en Argentina

“…En los frigoríficos de todo el mundo se realizan actividades sistemáticas dirigidas a reducir la carga de ECvt-SUH. Las más frecuentes, ya sea de forma individual o combinada, son la aspiración, la pasteurización por vapor y el lavado con soluciones orgánicas de ácido lác-tico, ácido peracético o ácido acético (35)(36)(37). Esta última técnica se destaca debido a su bajo costo, fácil aplicación e inocuidad para la salud pública (37).…”

“…Por otra parte, los ácidos orgánicos permiten reducir la carga de ECvt-SUH, pero no la frecuencia, es decir, si no se controla el número de animales que ingresan al faenado con ECvt-SUH en las heces, el impacto de esta medida sería limitado (36,37,49). La principal desventaja que podría generar el duchado de las canales con ácidos orgánicos son los cambios indeseables en el color de la carne: una mayor luminosidad y tonalidad e inferior índice de decoloración (50); esto favorece el rechazo por parte de los consumidores dada las exigencias en la cultura gastronómica del país (51).…”