A study published in the Journal of Food Science shows that nanoparticles may be effective at inhibiting some pathogens. For the study, zinc oxide quantam dots (ZnO QDs), nanoparticles of purified powdered ZnO, were evaluated for antimicrobial activity against Listeria monocytogenes, Salmonella Enteritidis, and E. coli O157:H7. The ZnO QDs were utilized as a powder, bound in a polystyrene film (ZnO-PS), or suspended in a polyvinylprolidone gel (ZnO-PVP). Bacteria cultures were inoculated into culture media or liquid egg white (LEW) and incubated at 22°C.
The inhibitory efficacies of ZnO QDs were concentration-dependent and also related to type of application. ZnO powder and ZnO-PVP showed significant antimicrobial activities against all three pathogens in growth media and LEW. No antimicrobial activities of ZnO-PS film were observed.