Reduction of bacterial load on broiler carcasses using low volume fluidic nozzles in combination with 60oC water at 450 psi pressure

Authors: Cosby, Douglas; MCLNTYRE, MICHEAL - Spraying Systems, Inc; DEVOLL, JOSH - Spraying Systems, Inc; JORDAN, AARON - Spraying Systems, Inc; Garrish, Johnna; Berrang, Mark; McMillan, Elizabeth

Submitted to: Poultry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/18/2024
Publication Date: 1/26/2024
Citation: Cosby, D.E., Mclntyre, M.D., Devoll, J., Jordan, A., Garrish, J.K., Berrang, M.E., Mcmillan, E.A. 2024. Reduction of bacterial load on broiler carcasses using low volume fluidic nozzles in combination with 60oC water at 450 psi pressure. Poultry. 3(1):15-25. https://doi.org/10.3390/poultry3010002.
DOI: https://doi.org/10.3390/poultry3010002

Interpretive Summary: Regulations in the poultry processing industry are continually changing and becoming more stringent. Poultry producers need to find ways to reduce the levels of human enteropathogenic bacteria on the final carcass or cut-up parts sold to the consumer. Current strategies focus on chemical antimicrobial interventions in the evisceration portion of the plants. This study details the development and pilot plant testing of a wash cabinet for use in the slaughter side of the plant for the reduction of total bacteria on the carcasses before the carcasses enter the evisceration side. The cabinet was tested at three sites, immediate prior to the scald tank, immediately after the scald tank and immediately after the picker/defeathering equipment. The highest level of reduction was seen when the wash cabinet was placed immediately before the scald tank. An average of2.5 log10 cfu/mL of total aerobic bacteria and 2.21 log10 cfu/mL of Campylobacter spp. were removed from the carcasses. Removal of these bacteria from the carcasses prior to entering the evisceration side of the plant should decrease the final number of bacteria on carcasses and allow the other intervention strategies to function better.

Technical 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 chill. 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 (60oC) 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 (N=20), placed into individual sterile sample bags, placed into insulated containers, and transported to the U.S. National Poultry Research Center Pilot Plant within 30 minutes of collection. Carcasses were hung in standard shackles and sampled pre-wash with pre-moistened, cellulose swabs along the keel of the sternum of each breast, three wipes per breast swab. All carcasses were washed with 60oC water at 450 psi at a line speed of 52 birds/minute. Post-wash breast sponge samples were collected identical to the pre-wash swabs. Ten mL of buffered peptone water was added to sample bags containing sponges, and sponges were stomached for 60 s. Total aerobic count (TAC), Enterobacteriaceae (ENT) and E. coli (EC) were enumerated by plating serial dilutions of the sponge rinsate on the appropriate PetriFilm® cards. All PetriFilm® cards were incubated at 37oC for 24 + 2 h. Samples were processed for Campylobacter species using the Tempo® CAM protocol. Four replications (N=60) were conducted on separate dates. Paired t-tests were used to compare numbers recovered from breast samples 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/mL (cfu/mL) of TA, 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 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 for TA, Ent, and EC Petrifilm, respectively and a 0.86 cfu/mL 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. This reduction should decrease the bacterial load of the carcasses and therefore increase the efficacy of other interventions used in processing plant to reduce the total number of bacteria on the finished carcass.