Characterization of Rosewood and Cinnamon Cassia essential oil polymeric capsules: Stability, loading efficiency, release rate and antimicrobial properties

In this study, Rosewood and Cinnamon essential oils (EO) were encapsulated using Tween 80 and poly(butylene adipate-co-terephthalate) (PBAT) as wall material. Capsules were obtained after solvent evaporation and evaluated by Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), Loading Efficiency (LE), Release, and Antimicrobial tests. SEM results showed that capsules' morphology was spherical with dimensions in the micrometer scale. Rosewood capsules presented agglomeration effects, while Cinnamon showed fewer defects. TGA for capsules presented a thermal event associated with encapsulated EO, which shows that the encapsulation process was successful. The LE was 11 and 29 %wt, for Rosewood and Cinnamon capsules, respectively. Those results are associated with the physical and chemical properties of the EO main compounds and their interaction with PBAT chemical structure. Therefore, it can be concluded that the nature of EO impacts the capsules' stability and LE. The release mechanism was adjusted according to the Korsmeyer-Peppas model, which shows an EO obeys Fickian diffusion process. The antimicrobial test showed significant inhibition against Escherichia coli, Listeria monocytogenes, Salmonella enterica, and Staphylococcus aureus. The effectiveness observed against these microorganisms could be applied to extend shelf life of food products by its incorporation into edible or thin films with food contact.

Automated summary

In this study, Rosewood and Cinnamon essential oils were successfully encapsulated using Tween 80 and PBAT as wall material, and evaluated through various tests. The nature of the essential oils was found to significantly impact the stability and loading efficiency of the capsules, while the release mechanism followed Fickian diffusion. Additionally, the capsules showed promising antimicrobial activity against various microorganisms.