Publications

Nanostructures have a great potential in the area of food packaging. This study aims to determine the antimicrobial efficacy for zinc oxide (ZnO) nanoparticles (Nps), compared to bulk ZnO powder. ZnO Nps were synthesized using; co-precipitation and high-speed ball milling method. The synthesized powders were characterized by X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet-Visible Absorption Spectroscopy (UV). All data revealed the formation of pure nano-sized ZnO. ZnO Nps showed notable size and concentration-dependent antimicrobial effects. In comparison to nanosuspension, the antimicrobial activity of bulk ZnO was almost negligible, a strong significant difference was noticed between the antimicrobial activity of the bulk and that of prepared Nps (p<0.05). ZnO Nps exhibited a privileged ability to suppress the growth of foodborne pathogens in culture media and milk samples. Among the bacterial strains tested, Gram-positive bacteria were more sensitive to ZnO nano-treatments. The examination of DNA of Bacillus subtilis treated with ZnO Nps using gel electrophoresis, displayed a reduction in band size but the absence of DNA fragmentation. Transmission Electron Microscope illustrated remarkable damages in the cell wall and cytoplasmic membrane of Bacillus subtilis cell structure upon exposure to ZnO Nps.