Development and characterization of geraniol-loaded polymeric nanoparticles with antimicrobial activity against foodborne bacterial pathogens

• Pluronic® F127 nanoparticles were loaded with essential oil component geraniol.
• Highly homogenous nanoparticles ranging from 26 nm to 412 nm could be prepared.
• Polymeric nature of NPs enabled geraniol release over 24 h at room temperature.
• Antimicrobial nanoparticles inhibited foodborne pathogens on spinach surfaces.

This study demonstrates the rose essential oil component (EOC) geraniol can be loaded into polymeric nanoparticles (NPs) with sustainable release profile. Geraniol-loaded NPs were prepared by flash nanoprecipitation and characterized for size, encapsulation efficiency, payload release during storage, inhibition of Escherichia coli O157:H7 and Salmonella enterica Typhimurium in vitro and on spinach surfaces, and NP-assisted transport of EOC into cellular membranes. Adjusting concentrations of stabilizing polymer, Pluronic® F-127, and geraniol produced NPs ranging in size from 26 to 412 nm. Antimicrobial NPs inhibited S. Typhimurium and E. coli O157:H7 growth at 0.25 and 0.2 wt.%, respectively. Geraniol-loaded NPs displayed sustained release with a time constant of 24 h, maintaining their anti-pathogenic properties over a prolonged time period. Pathogen reductions on treated spinach surfaces ranged from 0.3 to 4.2 log10 CFU/cm2. Antimicrobial NPs may be useful for post-harvest decontamination of foods such as fresh produce from cross-contaminating microbial pathogens.