Green synthesis of ZnO nanoparticles using Mentha piperita (Peppermint) extract and evaluation of their antimicrobial potential against Listeria monocytogenes

Nanoparticles have emerged as vital units in the realm of food processing and preservation. This study aims at the utilization of Mentha piperita for the green synthesis of zinc oxide nanoparticles. The peppermint plant, a hybrid of water mint and spearmint, was selected for its ready availability and widespread recognition for its medicinal properties. Moreover, zinc oxide is known for its antimicrobial attributes. Green synthesis of zinc oxide nanoparticles was done using zinc acetate and peppermint extract. Characterization of nanoparticles was done by UV-Visible Spectrophotometry, SEM, and EDX techniques. Confirmation of nanoparticles was achieved through distinct color change and the peak in UV-Vis at 350 nm. SEM results also confirmed the size of zinc oxide nanoparticles around 85.4 nm and were spherical in shape. The purity of the nanoparticles was confirmed by EDX showing 100% abundance of zinc and oxygen. Subsequently, antimicrobial activity of the nanoparticles was checked against multidrug-resistant L. monocytogenes strains, and it was found to be effective with an inhibition zone ranging from 30 to 35 mm. A five-week food testing procedure revealed that ZnO nanoparticles effectively inhibited foodborne pathogens with a delayed visual deterioration of tomatoes. This research signifies a promising stride in the application of zinc oxide nanoparticles in the realm of food safety and antimicrobial intervention.