Salmonella Reduction and Transfer Potential during Simulated Postchill Immersion of Chicken Thighs in Peroxyacetic Acid

This study evaluated whether peroxyacetic acid (PAA) could reduce Salmonella on inoculated chicken thighs and prevent its transfer to adjacent noninoculated parts under simulated postchill tank conditions. Bone-in, skin-on chicken thighs were surface inoculated with either a high (ca. 7 log CFU/ml) or low (ca. 4 log CFU/ml) concentration of a five-serovar Salmonella enterica cocktail. One inoculated thigh was immersed for 30 s alongside five noninoculated thighs in solutions containing either 540 ppm of PAA or chilled water, with organic matter levels of 1.5 or 3.0%. PAA treatment achieved significant reductions in Salmonella counts on inoculated samples (1.55 to 2.26 log CFU/ml rinsate), regardless of organic matter level or inoculum concentration. In contrast, water controls yielded ≤0.91 log CFU/ml reductions. However, all noninoculated thighs tested positive for Salmonella by enrichment after treatment, confirming the potential for cross-contamination across all conditions, even when PAA was present. Chemical oxygen demand and total nitrogen increased after treatment, consistent with organic matter accumulation during processing. Although PAA is effective for quantitative Salmonella reduction on contaminated parts, it does not prevent pathogen transfer during shortterm immersion. This underscores the need to reevaluate immersion-based antimicrobial strategies and implement additional preventive measures to mitigate residual crosscontamination risks in poultry processing.