Geraniol-Loaded Polymeric Nanoparticles Inhibit Enteric Pathogens on Spinach during Posttreatment Refrigerated and Temperature Abuse Storage

Antimicrobial-Loaded Polymeric Micelles Inhibit Enteric Bacterial Pathogens on Spinach Leaf Surfaces During Multiple Simulated Pathogen Contamination Events

“…We are not surprised by the observed differences in spinach decontamination outcomes for the GPN and HOCl treatments, given our previous published research on antimicrobial-loaded nanoparticles applied to decontaminate spinach (Perez-Lewis et al, 2018;Ruengvisesh et al, 2019a). Finally, the current study details the capability of the plant-derived antimicrobial geraniol, free and encapsulated within polymeric micelles, to reduce the numbers of inoculated E. coli O157:H7 and S. Typhimurium on spinach leaves during a simulated multicontamination spinach production and post-harvest handling scenario.…”

“…The current study sought to evaluate the produce surfacesanitizing utility of an innovative antimicrobial treatment composed of polymeric nanoparticles loaded with the PDA geraniol, as well as free geraniol and 200 ppm free chlorine, in a scenario involving multiple sequential spinach contamination events. In previous research, identically-prepared GPNs prevented growth of these organisms on spinach surfaces during refrigerated and temperature abuse storage, and showed capacity to inhibit pathogen growth when applied prior to pathogen inoculation (Perez-Lewis et al, 2018). Figure 2A depicts the size distribution of GPNs via DLS analysis, and indicates a mean particle size of 416.5 ± 77.9 nm.…”

“…The research data presented in the current manuscript were collected simultaneously with data already previously published by our group, wherein we identified multiple potential study limitations (Perez-Lewis et al, 2018). In addition to the potential study limits discussed in that report, there remain potential concerns over the financial costs of nano-particle formulation and preparation, and the demand for "clean" food ingredients used in food manufacturing that may limit produce industry adoption (Mora-Huertas et al, 2010;Blanco-Padilla et al, 2014).…”

“…One strategy to overcome these limitations of PDAs is to encapsulate them in a water-miscible system to facilitate their delivery to produce surfaces, potentially improving on observed antimicrobial effects (Yegin et al, 2016). The application of nanoparticles constructed of the tri-block co-polymer Pluronic F-127 loaded with the PDA geraniol (trans-3,7-Dimethyl-2,6-octadien-1-ol) inhibited the growth of E. coli O157:H7 and S. Typhimurium on spinach over 10 days of refrigerated storage, reducing pathogen numbers to non-detection within 5 days of experiment initiation (Perez-Lewis et al, 2018). Geraniol has been reported to exert antimicrobial activity against bacterial organisms through its impacts on membrane components, resulting from significant destabilization of membrane phospholipid arrangement and packing, as well as through formation of aggregates of lipids leading to increase leakage of solutes (Nowotarska et al, 2014).…”

Inhibition of bacterial human pathogens on tomato skin surfaces using eugenol‐loaded surfactant micelles during refrigerated and abuse storage

“…To selectively/differentially enumerate pathogens, samples were placed in stomacher bags and pummeled (230 rpm) with 99 ml sterile 0.1% (wt/vol) peptone diluent for 1.0 min. Surviving pathogens were serially diluted in 9.0 ml sterile 0.1% peptone diluent and then spread on surfaces of lactose‐sulfite‐phenol red‐rifampicin agar supplemented with 100.0 μg/ml rifampicin according to methods previously published (Perez, Lucia, Cisneros‐Zevallos, Castillo, & Taylor, ; Perez‐Lewis et al, ). The limit of detection for plating assays was 100 cfu/30 cm 2 (0.5 log 10 cfu/cm 2 ).…”