Evaluation of antimicrobial activity of magnesium oxide nanocomposite film in combination with ε-poly-L-lysine against Foodborne pathogens in vacuum packaged beef

Background: The aim of this study was to evaluate the antimicrobial activity of magnesium oxide nanocomposite (MgO NC) film based on Low-density polyethylene (LDPE) alone or in combination with three concentrations of ε-poly-L-lysine (500, 1000 and 2000 µg/ml) on Escherichia coli O157:H7 and Listeria monocytogenes in culture media and fresh beef. Methods: MgO NC film were prepared by melt mixing LDPE and MgO nanoparticle in the extruder. For in vitro antibacterial analysis, the MgO NC film alone or in combination with polylysine were evaluated in tryptic soy broth for 5 days at 37 °C. For in vivo analysis, beef samples were inoculated with the selected bacteria and packaged in MgO NC film under vacuum and stored at 4 °C and evaluated for up to 20 days. Results: Polylysine had an antibacterial effect against E. coli and L. monocytogenes in TSB. But MgO NC film had a bacteriostatic effect only against E. coli. MgO NC film inhibited the growth of E. coli on the surface of beef samples. Pollysine at concentrations of 500 µg/ml or more showed inhibitory activity against E. coli and L. monocytogenes in beef samples. No additional reduction was observed by combining the different concentrations of polylysine with MgO NC film.Conclusions: Polylysine at all concentrations had an inhibitory effect on E. coli and L. monocytogenes in the culture medium and beef. Although the migration of MgO nanoparticle from the film to beef was very low, but as it has little antimicrobial effect, it is not recommended as a suitable package for improving the safety of raw beef.

Magnesium oxide incorporated electrospun membranes inhibit bacterial infections and promote healing process of infected wounds

Bacterial infections cause serious secondary damages to wounds and hinder wound healing processes. We prepared magnesium oxide (MgO) nanoparticle-incorporated nanofibrous membranes by electrospinning and investigated their potential for wound dressing...

Preparation and Synergistic Effect of Chitosan/Sodium Phytate/MgO Nanoparticle Fire-Retardant Coatings on Wood Substrate through Layer-By-Layer Self-Assembly

Fire-retardant chitosan/sodium phytate/MgO nanoparticle (CH/SP/nano-MgO) coatings were loaded on a wood substrate via electrostatic layer-by-layer self-assembly and characterized by scanning electron microscopy and energy-dispersive spectrometry. The flammability and thermal degradation of the original wood and wood samples treated with chitosan, chitosan/sodium phytate, chitosan/sodium phytate/MgO nanoparticles were studied by limiting oxygen index (LOI), exposure combustion experiments and thermogravimetric analysis (TGA), respectively. The CH/SP/nano-MgO coating served as an intumescent fire-retardant system that created a physical protection cover and exhibited the best fire retardant performance. The LOI value was 30.2% and required approximately 16–17 s to self-extinguish when exposed to air. The TGA curves also showed that char formation protected the wood from combustion.