Antibacterial Effects of Zinc Oxide Nanoparticle and Ginger Oil Nanoemulsion in Fish Fillet Keeping Quality

In the current study, the antibacterial effect of zinc oxide nanoparticles (ZnO NPs) and ginger oil nanoemulsion (GNE) were determined by their application on experimentally inoculated fish fillet with nearly 4 log10 CFU/g Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in separately treated groups and were kept in a refrigeration condition (4±1oC). For investigation of their antibacterial potential, ZnO NPs and GNE were used in concentrations of 12 mM and 5.0%, respectively either alone or in combination with each other. Characterizations results of the used nanomaterials revealed that the size of ZnO NPs and GNE were 20 and 17.94 nm, respectively. Regarding with their antibacterial effect, different investigated treatments inhibited significant antibacterial effect against S. aureus and E. coli through inhibition of their multiplication significantly in comparison with control group. Results revealed that the combination treated groups (ZnO NPs + GNE) showed higher reduction % than the other treated groups that strongly proved the synergistic effect of their combination against foodborne bacteria. In addition, extended organoleptic acceptability and shelf-life, consequently, of the treated fish fillet samples were recorded in comparing with the control untreated groups. Moreover, over longer time exposure, treated groups with GNE showed longer organoleptic acceptability criteria than that treated with ZnO NPs. Furthermore, S. aureus showed higher resistance potential against the used nanomaterials than E. coli. Through the recorded results, ZnO NPs and GNE showed potent antibacterial effects against S. aureus and E. coli fish borne bacteria; therefore, it is strongly recommended to be used as food additive; whereas, environmental safety and residue potential still need more investigations.