The development of efficient, eco-friendly antimicrobial agents for air purification and disinfection addresses public health issues connected to preventing airborne pathogens. Herein, the antimicrobial activity of a nanoemulsion (control, 5%, 10%, and 15%) containing neem and lavender oils with polycaprolactone (PCL) was investigated against airborne bacteria, including Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Various parameters such as the physicochemical properties of the nanoemulsion, pH, droplet size, the polydispersity index (PDI), the minimum inhibitory concentration (MIC), the minimum bacterial concentration (MBC), and the color measurement of the emulsion have been evaluated and optimized. Our results showed that the antimicrobial activity of PCL combined with neem and lavender oil was found to be the highest MIC and MBC against all tested bacteria. The droplet sizes for lavender oil are 21.86–115.15 nm, the droplet sizes for neem oil are 23.92–119.15 nm, and their combination is 25.97–50.22 nm. The range of pH and viscosity of nanoemulsions of various concentrations was found to be 5.8 to 6.6 pH and 0.372 to 2.101 cP. This study highlights the potential of nanotechnology in harnessing the antimicrobial properties of natural essential oils, paving the way for innovative and sustainable solutions in the fight against bacterial contamination.

In this study, the effects of gamma radiation on the decontamination of fungus, physicochemi-cal properties, and molecular analysis of Aspergillus spp. of common spices for storage were evaluated. After being irradiated with gamma doses of 0, 2, 4, and 6 kGy and sealed in glass vials, the spices were stored at room temperature for 180 days. Among the tested spice samples, chili, turmeric, and black pepper powder showed the highest presence of fungal contamination compared to cumin, coriander, garlic, and ginger samples. Microscopy was used to identify a total of 48 isolates, of which 11 were Mucor, 25 were Penicillium, and 12 were Aspergillus. By polymerase chain reaction (PCR) amplification and sequencing of the internal transcribed spacer (ITS) region, a total of 12 Aspergillus genera were identified among them: 5 in black pepper and 7 in red chili. The gamma radiation also reduced the number of microbes compared to the control group. The best gamma radiation doses were found to kill the organ-isms in the studied spices. These were 6 kGy for red chili, 4 kGy for turmeric and black pepper, and 2 kGy for cumin, coriander, garlic, and ginger. Measurements of the physicochemical parameters were not significantly impacted by the 180-day exposure to gamma radiation; however, the number of fungi drastically decreased. Gamma radiation has been explored as an effective method for decontaminating spices, offering a promising solution for ensuring food safety and quality.