APPLICATION OF ACIDIC CALCIUM SULFATE AND ε-POLYLYSINE TO PRE-RIGOR BEEF ROUNDS FOR REDUCTION OF PATHOGENS

Abstract

ABSTRACT This study evaluated the effectiveness of warm solutions of acidic calcium sulfate (ACS), lactic acid (LA), ε-polylysine (EPL), ACS plus EPL and sterile distilled water (W) applied to the surface of fresh, pre-rigor beef rounds for reducing Salmonella Typhimurium, Escherichia coli O157:H7 and Listeria monocytogenes applied as a cocktail at a level of 6.4 log cfu/ 50 cm2. All treatments were applied for 15 to 20 s using a stainless steel spray cabinet at 50–55C under a constant pressure. Sequential application of warm ACS, followed by EPL significantly reduced inoculated levels of S. Typhimurium, E. coli O157:H7 and L. monocytogenes, with an extended effect over seven storage days. This combination was more effective than single treatments of ACS, LA, EPL or W alone. From these results, it appears that a sequential application of ACS and EPL could be a better strategy for pathogen reduction in meat plants than a single decontamination treatment. PRACTICAL APPLICATIONS A sequential application by spray of acidified calcium sulfate (ACS) followed by ε-polylysine (EPL) reduced pathogens on pre-rigor beef rounds more effectively than a single treatment of ACS, EPL, lactic acid or water. This indicates that multiple interventions can be a better strategy for pathogen reduction than single treatments, and could also provide a more “fail-safe” pathogen reduction strategy. It also appears that combinations of antimicrobial agents that have different modes of action for suppressing pathogen growth, and the sequential application of different decontamination sprays are significant factors for obtaining greater reductions in pathogen numbers on beef carcasses at slaughter.