Assessing beef hide interventions as a means to reduce carcass contamination

Abstract

Food safety is a critical issue for beef harvest operations. There are multiple interventions available for treating carcasses; however, this project was designed to evaluate an intervention capable of reducing bacterial counts on the hide prior to opening in order to minimize carcass contamination. In Trial I, fresh beef hides (n = 12) were cut into sections and assigned to serve as either clipped (hair trimmed) or non-clipped sections. Sections were inoculated with a bovine fecal slurry and sampled following a water wash. Treatments (distilled water, isopropyl alcohol, 3% hydrogen peroxide, 2% L-lactic acid, 1% cetylpyridinium chloride (CPC), and 10% Povidone-iodine) then were applied to each section and sampled for aerobic plate counts (APCs), coliform, and Escherichia coli counts. Within clipped samples, 1% CPC and 3% hydrogen peroxide caused the greatest reductions in aerobic plate counts, and 1% CPC, 2% L-lactic acid, and 3% hydrogen peroxide showed among the greatest reductions in coliform counts. In Trial II, beef carcasses with hides on were sampled initially and clipped, and then antimicrobials (2% L-lactic acid, 3% hydrogen peroxide, and 1% CPC) were applied before sampling again for APC, coliform, and E. coli counts. This procedure was replicated in Trial II utilizing a non-pathogenic E. coli Type I indicator strain transformed to produce a green fluorescing protein (GFP). In Trial II, though few differences existed between antimicrobial treatments, all three (1% CPC, 2% L-lactic acid, and 3% hydrogen peroxide) resulted in approximately a 2-log10 CFU/100-cm2GFP reduction when applied to clipped hide surfaces in the brisket region of the carcass. In Trial III, 1% CPC produced the greatest reduction on the hide surface for APCs. In Trial IV clipped beef hide sections were sampled initially and then antimicrobials (2% L-lactic acid, 3% hydrogen peroxide, and 1% CPC) were applied before sampling again to determine reduction. Trial IV also involved the use of the E. coli GFP indicator strain. In Trial IV, non-clipped samples had a mean reduction of 2.8 log10 CFU/100 cm2, and clipped samples had a mean reduction of 2.2 log10 CFU/100 cm2. Within the antimicrobials tested, 1% CPC and 3% hydrogen peroxide produced the greatest reductions.