Invitro decontamination effect of zinc oxide nanoparticles (ZnO-NPs) on important foodborne pathogens

Abstract

Zinc oxide (ZnO) has been used for many years in the pharmaceutical, cosmetic, paint, textile, and foodindustries for coating surfaces, absorbing UV rays and due to its antimicrobial properties in nanoscale, it has beenidentified as an important chemical for decontamination. Zinc can be found in many foods as well and its alloweddaily intake for adults has been reported as 8-11 mg. Zinc Oxide Nanoparticles (ZnO-NPs) are generally regarded assafe (GRAS) for it being stable under hard processing conditions. Compared to organic acids, ZnO-NPs have betterdurability, selectivity, and heat resistance. In the present study, it was aimed to understand the decontaminationeffect of ZnO-NPs on S. enteritidis, S. typhimurium, S. aureus, L. monocytogenes, and E. coli O157 to develop novel,safe decontamination agents for the food industry. For this purpose, <50 µ ZnO-NPs were added into Tryptic SoyBroth in 20 mMolar final concentration for the understanding of the antimicrobial effect. After inoculation of thepathogens, a counting procedure was performed using the Tryptic Soy Agar by the pour on plate method at 0, 1st,2nd, 4th, 6th, 8th, 12th, and 24th hours. As a result, S. enteritidis and S. aureus 3 Log CFU/mL, S. typhimurium and E. coliO157 4 Log CFU/mL, L. monocytogenes 2 Log CFU/mL decreased in 24 hours.