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Identification and validation of antimicrobial interventions for red meat carcasses processed in very small meat establishment

by Flowers, Sally Lucile.

Abstract (Summary)
Carcass decontamination strategies for very small meat plants (VSMP) were developed by systematic experimentation. First, a survey of VSMP in Pennsylvania, Washington and Idaho determined that knife trimming and cold water washing were the most common antimicrobial interventions in use. Secondly, red meat carcasses (n = 866) processed in VSMP in Pennsylvania, Washington, Idaho, and Texas were swabbed to determine prevalences of Salmonella spp., Campylobacter spp., and E. coli O157:H7 and enumerate hygiene indicators (mesophilic aerobic plate count, coliforms, and generic E. coli). Thirdly, manual water washes (various temperatures, pressures, drip times, applications, and distances) and chemical rinses at various concentrations (acetic acid, citric acid, lactic acid, peroxyacetic acid, aqueous ozone, sodium hypochlorite, chlorine dioxide, and acidified sodium chlorite) were applied in inoculation challenge studies to reduce bacteria on inoculated beef surfaces. While hot water (77°C) yielded log reductions of 2.7 to 5.1 CFU/cm iii 2, there were quality issues with this intervention. Relative antimicrobial effectiveness was determined: organic acids > peroxyacetic acid > chlorinated compounds > ozone. Using this information, individual and combined effectiveness of water washing and/or rinsing with an antimicrobial compound was measured in a laboratory setting. The effectiveness of a portable, pressurized stainless steel spray tank to apply a 2% lactic acid rinse was compared with a garden sprayer, retrofitted garden sprayer, and motorized backpack sprayer. The findings from these studies indicated that a manual warm water wash (54°C), followed by a 5 minute drip and 2% lactic acid rinse applied with a portable, pressurized steel tank, was the most effective multi-step antimicrobial carcass intervention (MSACI) with reductions of pathogens between 3.5 and 5.0 log CFU/cm2 and 3.8 to 8.9 log CFU/cm2 for hygiene indicators. Instructional materials were developed to train VSMP employees how to implement MSACI in their plants. Lastly, red meat carcasses (n = 747) were swabbed to generate a second microbiological baseline after MSACI implementation. The first and second baselines were statistically compared to validate the reduction in carcass hygiene indicators and prevalence of harmful pathogens. Overall, MSACI was deemed an effective and feasible method of improving the microbiological safety of carcasses processed in VSMP. iv
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School:Pennsylvania State University

School Location:USA - Pennsylvania

Source Type:Master's Thesis

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