Inhibitory activities of quaternary ammonium surfactants against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes inoculated on spinach leaves

Publication date: Available online 17 December 2018Source: LWTAuthor(s): Ji-Hoon Kang, Jun-Beom Park, Kyung Bin SongAbstractAntimicrobial activities of quaternary ammonium surfactants (QAS) have been reported, but the effects of various QAS on the disinfection of foodborne pathogens on fresh produce have not been compared. Thus, the objective of this study was to determine the most effective QAS to be used as a disinfectant for fresh produce to replace chlorine-based sanitizers through comparison of inhibitory activities of the various QAS (benzalkonium chloride, benzethonium chloride, cetylpyridinium chloride, cetyltrimethylammonium bromide, tetraethylammonium bromide) against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes inoculated on spinach leaves. Among the QAS used in this study, cetylpyridinium chloride (CPC) exhibited maximum inhibitory activity because of its high positive ζ–potential value (67.23 mV), resulting in 3.33, 3.28, and 4.54 log-reductions against E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively. The microbial count reductions by CPC were higher than those obtained by NaOCl treatment at 80 mg/L. The CPC treatment produced fewer injured cells than NaOCl treatment. In addition, CPC treatment did not alter the surface color and weight loss of spinach samples during storage. Thus, these results suggest that CPC could be used as an effective sanitizer to improve the microbial safety of spinach leaves.
Source: LWT Food Science and Technology - Category: Food Science Source Type: research