Microencapsulation of Gaultheria procumbens essential oil using chitosan-cinnamic acid microgel: Improvement of antimicrobial activity, stability and mode of action

- Chitosan-cinnamic acid (Cs-Ci) microgel was prepared through cross-linking with EDC.
- Encapsulation of Gaultheria procumbens essential oil (GPEO) within Cs-Ci microgel.
- Antifungal and aflatoxin B1 inhibitory activity of microencapsulated GPEO.
- Elucidation of the antifungal mode of action of microencapsulated GPEO.
- Recommended Cs-Ci microgel as an encapsulating material for essential oils.

The present study was undertaken to investigate the efficacy of chitosan-cinnamic acid based microencapsulated Gaultheria procumbens L. essential oil (GPEO) against Aspergillus flavus (EC-03), aflatoxin B1 secretion and its mode of action. Scanning electron microscopy (SEM) and particle size analyzer analysis revealed that the microencapsulated GPEO exhibited an even spherical shape and particle size ranged between 7.00 and 90.0 μm. During chemical characterization (GC-MS), methyl salicylate (96.25%) was identified as the major component of GPEO. Microencapsulated GPEO exhibited strong antifungal and aflatoxin B1 suppressor activity than the uncapsulated GPEO and completely inhibited growth and toxin production at 1.00 μL/mL. The mode of action of microencapsulated GPEO was elucidated targeting ergosterol content in the cell membrane, the release of cellular ion contents and morphological alteration in A. flavus. The results demonstrate the potential of chitosan-based encapsulating material for the improvement of the antimicrobial efficacy as well as stability of GPEO.