Comparison of antibacterial and antioxidant potentials of pure and nanoemulsified Nepeta pogonosperma essential oil

Abstract

The current study aimed to investigate the antiradical and antibacterial potential of pure and its nanoemulsified (NNE) Nepeta pogonosperma essential oil (PNE). Antimicrobial activity of the essential oil against two Gram‐positive (E. faecalis and B. cereus) and two Gram‐negative (M. catarrhalis and K. pneumonia) food‐related pathogens during 60‐day storage was investigated based on disc diffusion, minimum inhibition concentration (MIC), and minimum bactericidal concentration (MBC). The chemical compounds of Nepeta essential oil were estimated by GC/MS. The physical properties of the nanoemulsion including polydispersity index (PDI), mean particle diameter, and viscosity were also determined. 4aα,7α,7aβ‐Nepetalactone (46.31%), 1,8‐cineole (23.13%), and (Z)‐α‐bisabolene (4.01%) were the main compounds of this essential oil. The Nepeta nanoemulsion had a mean droplet diameter of 254.07 nm, PDI of 0.281, and viscosity of 0.887 cP. NNE had stability for up to 60 days. The PNE showed a higher IC50 value than NNE (p < .05). During storage, the antiradical performance of both PNE and NNE was decreased (p < .05). However, emulsification was successful to control this decreasing trend. E. faecalis was the most susceptible bacteria to PNE and NNE, while the lowest inhibition zone was obtained for K. pneumoniae. At the first time, the antibacterial effect of PNE was more than NNE. However, over time nanoemulsion became more successful in maintaining its antibacterial effect. Overall, the incorporation of Nepeta pogonosperma essential oil into a nanoemulsion system can be a promising system to maintain the bioactivity of the essential oil for a longer time.

Effects of Cuminum cyminum L. essential oil and its nanoemulsion on oxidative stability and microbial growth in mayonnaise during storage

“…The stronger antioxidant activity of the essential oil nanoemulsions can be related to the smaller size, greater solubility, and better permeability of droplets than essential oil emulsions; as a result, more free radicals are involved by the scavenging effects of essential oil nanoemulsions. Moreover, the pure essential oil is not able to dissolve in aqueous systems (Dhifi et al, 2016), which reduces its antioxidant activity compared with the nanoemulsion essential oil (Sharifi & Sharifi, 2023). However, nanoemulsions can dissolve in aqueous systems, which leads to the efficient release of activated compounds; subsequently, they can more effectively scavenge radicals (Lou et al, 2017).…”

“…Droplet size and microstructure of CEONIn general, reducing the particle size leads to an increase in the surface area of particles(Csicsák et al, 2023), especially at the nanoscale. Reducing the average size of essential oil droplets in the nanoemulsion system increases the availability of bioactive compounds and as a result, the antioxidant and antimicrobial properties of the nanoemulsion compared with pure essential oil(Sharifi & Sharifi, 2023). Therefore, nanoemulsion particles with a size smaller than 100 nm are more suitable for greater utilization of their antimicrobial and antioxidant properties(McClements & Li, 2010).…”

Effect of Apple Pomace Powder Addition on the Physicochemical Properties of Oily Cakes and Ranking Samples by Delphi Fuzzy Approach

“…Plants are considered as valuable natural sources that have got a great attention in food industry due to their antioxidant potentials [1]. In food industry, diferent fruits and vegetables are processed to produce various value-added products.…”