Studies on Standardization of Activation Process of Persulfate for Decontamination against Food Pathogens

Abstract

The present investigation was carried out to standardize the activation process of sodium persulfate for its antimicrobial application against selected foodborne pathogens, namely Escherichia coli, Listeria monocytogenes and Salmonella typhimurium. In this study, sodium persulfate (PS) was activated using three approaches, viz., ferrous sulphate (FeSO₄), sodium hydroxide (NaOH) and ultraviolet-C (UV-C) radiation. Different concentrations of PS (30-90 mmol/L) and exposure times (1-5 min.) were tested to evaluate their efficiency. All activation methods produced a significant reduction in microbial counts (p < 0.0001), with inhibition generally increasing with concentration and treatment time. Complete inactivation was achieved in several cases, such as FeSO₄ activation at 50 mmol/L for 1 min. against E. coli and L. monocytogenes, and NaOH activation at 90 mmol/L for 3 min. against L. monocytogenes. In the case of S. typhimurium, complete inhibition was obtained at 30-40 mmol/L PS activated with FeSO₄ or NaOH. Although UV-C activation was effective, it required longer exposure times (45-60 min.) which limit its practical use. From the study, three optimized treatments were identified: PS activated with FeSO4 (50 mmol/L, 1 min.), PS activated with NaOH (50 mmol/L, 1 min.) and PS activated with NaOH (90 mmol/L, 3 min.). The results suggest that activated sodium persulfate could be considered a potential alternative to conventional chlorine-based sanitizers for microbial decontamination in fresh produce handling.