Peroxyacetic Acid as a Low-Dose, pH-Stable Alternative to Sodium Hypochlorite for Pathogen Reduction and Flavor Control in Fresh Vegetable Disinfection

Foodborne illness from fresh vegetables remains a major concern. Sodium hypochlorite (SH), the most widely used disinfectant, poses health risks due to persistent residues and harmful disinfection byproducts. Although peroxyacetic acid (PAA) was approved as a food disinfectant in Korea in 2018, its bactericidal efficacy and impact on vegetable flavor under industrial conditions have not been systematically evaluated. In this study, we evaluated and compared the bactericidal efficacy of PAA and SH against <i>Escherichia coli</i>, <i>Salmonella</i> Typhimurium, and <i>Staphylococcus aureus</i> on lettuce (<i>Lactuca sativa</i>) and paprika (<i>Capsicum annuum</i>), and assessed flavor impact using electronic nose technology. The results demonstrated that 60-80 ppm PAA achieved rapid and potent pathogen reduction. Specifically, treatment with 60 ppm PAA for 2 min reduced all three pathogens on lettuce to below detection limits (>6.0 log₁₀ CFU/g reduction), whereas 40 ppm PAA for 2 min eliminated <i>E. coli</i> and <i>S.</i> Typhimurium on paprika, and 60 ppm PAA for 30 s eradicated <i>S. aureus</i>. PAA exhibited significantly stronger bactericidal activity than SH at lower concentrations, with 60 ppm PAA being equivalent in efficacy to 200-300 ppm of SH. Notably, PAA maintained consistent performance across pH 3-9 while avoiding the disinfection byproducts (DBPs) risks associated with SH. Electronic nose analysis indicated concentration-dependent flavor alterations, though effects were negligible at ≤60 ppm compared with 80 ppm. These findings establish PAA as an effective and environmentally compatible alternative to SH for industrial vegetable disinfection, enhancing food safety while minimizing sensory compromise.