Purpose: The purpose of this study was to validate the effectiveness of peroxyacetic acid (PAA) for use in on-line (OLR) and off-line (OFLR) reprocessing to reduce microbial populations on contaminated poultry carcasses.
Methods: In-plant trials were conducted on eighty carcasses identified by USDA FSIS as visually contaminated (VCO) and visually non-contaminated (VCL). Carcasses were processed through the plant’s normal OLR or OFLR processing system containing PAA (25-100 ppm). Carcass samples were rinsed (1 min, 400 ml buffered peptone water); rinsates pH neutralized with sodium thiosulfate, and analyzed for generic E. coli, aerobic bacteria (APC), Salmonella, and Campylobacter. Microbiological data were analyzed using Minitab Two-Sample t-Test and means separated using Tukey’s method (α = 0.05).
Results: Findings demonstrate that PAA is an effective OLR and OFLR antimicrobial treatment to reduce APC, E. coli, Salmonella spp., and Campylobacter mean populations on poultry. APC and E. coli counts were significantly reduced (P < 0.05) from 4.5 ± 0.3 to 4.0 ± 0.4 and 3.1 ± 0.6 to 2.4 ± 0.8 log CFU/ml, respectively, on VCL carcasses and from 4.4 ± 0.5 to 3.3 ± 0.7 and 3.1 ± 0.8 to 2.4 ± 0.8 log CFU/ml on VCO carcasses through OLR treatment. Salmonella and Campylobacter were also reduced on carcasses treated on-line and off-line with PAA. Interestingly, E. coli and APC mean counts (VCO) measured at OFLR were surprisingly similar to those for OLR considering trials were conducted several months apart. This suggests that OLR systems treated with PAA could be suitable for reprocessing heavily contaminated carcasses eliminating required OFLR.
Significance: These data and application parameters can be used to support and validate PAA as an OLR and OFLR antimicrobial permitted for organic and export poultry products.