The efficacy of essential oil components loaded into montmorillonite against Aspergillus niger and Staphylococcus aureus

Abstract

Essential oil components (EOCs) are potent natural antimicrobial agents, but their high volatility and reactivity limit their potential applications. Here, we report the preparation of a series of nanomaterials containing EOCs (i.e., allyl isothiocyanate, carvacrol, cinnamaldehyde, diallyl disulphide, eugenol and thymol). The materials were prepared by simple adsorption of the EOCs onto a montmorillonite nanoclay. The antimicrobial activities of these materials were assessed against Aspergillus niger and Staphylococcus aureus as typical models of agricultural fungal pathogens and foodborne bacterial pathogens, respectively. In addition, the activities of the encapsulated EOCs were compared with those of the corresponding free forms with or without Tween‐80 in two types of assays: microdilution assays for determining the minimum inhibitory concentration (MIC) and agar‐based assays mimicking surface treatment. Enhanced antifungal activity of the encapsulated form was observed for all EOCs. In addition, against S. aureus, the MICs of all EOCs were remarkably lower in encapsulated form than in free form. These results indicate that EOCs encapsulated in low‐cost nanoclays have favourable potential as antimicrobials compared with the pure compounds.

Antibacterial Effect of Thymol Loaded SBA-15 Nanorods Incorporated in PCL Electrospun Fibers

“…These values were much lower than the ones previously found for free THY, obtaining MIC and MBC values of 0.2 and 0.3 mg/mL, respectively [30]. The increase of the antibacterial activity associated with encapsulation was previously reported for essential oil components loaded into montmorillonite [52]. The enhanced antibacterial activity was attributed to the slower evaporation rates of the encapsulated compounds.…”

Effect of Lemon Waste Natural Dye and Essential Oil Loaded into Laminar Nanoclays on Thermomechanical and Color Properties of Polyester Based Bionanocomposites

“…The preparation of MMT-essential oil powders with oregano, thyme and basil oils was reported showing a significant modification in the basal space of MMT clay and increased EO thermal stability with the EO adsorption [17,25]. Nanomaterials with different EO components were prepared by Bernardos et al [26] by adsorption onto a montmorillonite nanoclay, obtaining enhanced antifungal activity against Aspergillus niger and Staphylococcus aureus compared to the corresponding free forms. The biocidal efficiency of alginate-MMT/lemon EO films against two fungal and four bacterial strains was addressed by Hammoudi et al [27] for the potential use in antimicrobial food packaging applications.…”

Release of Cinnamaldehyde and Thymol from PLA/Tilapia Fish Gelatin-Sodium Alginate Bilayer Films to Liquid and Solid Food Simulants, and Japanese Sea Bass: A Comparative Study

“…The antibacterial activity of essential oils was primarily achieved by damaging the integrity of the bacterial cell membrane, increasing the permeability of the cell membrane, destabilizing the enzymes located in the cytoderm, and disrupting many cellular activities [ 1 ]. Especially, CI was reported to inhibit ATPase and disrupt the outer cell membrane; Ty can affect the permeability of the membrane and induce leakage of intracellular materials by disturbing the lipid fraction of bacterial plasma membranes [ 47 , 48 ].…”