Reduction of Bacterial Load on Broiler Carcasses Using Low-Volume Fluidic Nozzles in Combination with 60 °C Water at 450 Psi Pressure

Abstract

With the changing regulations in poultry processing, increased pressure is placed on integrators to reduce the number of human enteropathogenic bacteria on the final carcass and/or parts. Reducing the total number of bacteria on broiler carcasses before entering the evisceration side of the processing plant is projected to reduce the number of bacteria on the carcasses after chilling. This study was designed to evaluate the efficacy of a prototype wash cabinet using low volume, fluidic nozzles in combination with high pressure (450 psi) and hot water (60 °C) to remove bacteria from pre-scald, post-scald, or post picked carcasses. Carcasses (n = 5) from each location were obtained from a commercial processing plant, placed into individual sterile sample bags, placed into an insulated container, and transported to the U.S. National Poultry Research Center Pilot Plant within 30 min of collection. Carcasses were hung in standard shackles and sampled pre-wash with pre-moistened, cellulose swabs. All carcasses were washed in the prototype wash cabinet with 60 °C water at 450 psi at a line speed of 52 birds/minute on 15.24 cm centered shackles. Post-wash breast sponge samples were collected identical to pre-wash swabs. Buffered peptone water (BPW) was added, sponges stomached and serially diluted before plating onto total aerobic count (TAC), Enterobacteriaceae (ENT) and Escherichia. coli (EC) Petrifilm® cards. All PetriFilm® cards were incubated at 37 °C for 24 ± 2 h. After incubation, bacterial counts were recorded and converted to log10 CFU/swab. Samples were processed for Campylobacter species using the Tempo® CAM protocol. Four replications were conducted on separate dates. Paired t-tests were used to compare numbers recovered from breast swabs collected before and after the wash cabinet, significance reported at p < 0.05. Pre-scald samples had significant reductions of 2.50, 2.01, and 1.73 log10 colony-forming units/carcass (CFU/carcass) for TAC, Ent, and EC Petrifilm®, respectively, and a 2.21 CFU/mL reduction of Campylobacter species using Tempo® CAM. Post-scald, there were significant reductions of 2.09, 1.23, and 0.90 CFU/carcass for TA, Ent, and EC Petrifilm®, respectively, and a 1.14 CFU/mL reduction of Campylobacter species using Tempo® CAM. Post-pick, significant reductions of 0.73, 1.53, and 0.99 CFU/carcass for TA, Ent, and EC Petrifilm®, respectively, and a 0.86 CFU/carcass reduction of Campylobacter species using Tempo® CAM were reported. These data indicate that hot water at high pressure can reduce total bacterial load on carcasses and reduce pathogenic bacteria on carcasses prior to evisceration.