Green Synthesis of Magnesium Oxide Nanoparticles: Optimisation, Characterisation and Antibacterial Potential Against Listeria monocytogenes

Biogenic nanoparticles effectively control Listeria monocytogenes in food processing areas due to their biocompatibility and non-toxic nature towards the environment. In this study, we synthesised magnesium oxide nanoparticles (G-MgO NPs) using Syzygium cumini as the reducing and stabilising agent. The parameters affecting the green synthesis process, including pH, precursor concentration and volume, extract volume, and temperature, were optimised for G-MgO NPs. The spectroscopic and microscopic analyses were used to characterise the prepared G-MgO NPs. The UV-visible spectra absorbance at 291 nm indicates the formation of nanoparticles. Zeta potential illustrated that the G-MgO NPs surface charges were 12.4 ± 5.2 mV. FESEM results demonstrated a particulate size range of 36 ± 0.7 nm. FTIR spectra analysis showed the presence of magnesium oxide functional groups at 428 cm⁻¹, and EDX profiling identified the magnesium and oxygen elements in the nanoparticle composition. The zone of inhibition measured for Listeria monocytogenes ATCC 19118 was 11.6 ± 0.8 mm for 25 mg/mL and 13.8 ± 0.6 mm for 50 mg/mL. For Listeria monocytogenes ATCC 35152, it was 13.8 ± 0.0 mm for 25 mg/mL and 17.2 ± 0.0 mm for 50 mg/mL. In conclusion, monitoring the various sources of contamination with Listeria monocytogenes in food processing environments is an essential factor to achieve efficient control. Moreover, preliminary research indicates that G-MgO NPs can be applied as promising disinfectants in food safety due to their bactericidal Effect against Listeria monocytogenes.