Encapsulation of volatile oils with antimicrobial activity in chitosan-βCD molecular inclusion complexes by spray drying

Abstract

Binary and ternary molecular inclusion complexes (MICs) of beta-cyclodextrin (βCD - binary), and chitosan-βCD (ternary) loaded with Lippia sidoides (LS) and Syzygium aromaticum (SA) volatile oils (VOs—pure and in 1:1 mixtures) were engineered by a modified slurry method followed by spray drying. Eugenol and Thymol, the major constituents of SA and LS VOs, were successfully retained in MICs, showing good values of the encapsulation efficiency (EE), molar ratio (MR), and VOs load (DL). EEs were higher for the pure VOs (68.7 ± 1.6 to 86.1 ± 4.0% w/w) compared to their mixtures (37.8 ± 1.4 to 65.9 ± 2.4% w/w). The chitosan addition increased the Thymol’s EE, while for Eugenol, an opposite effect was exhibited. The MICs formed showed slight changes in the volatiles' composition, evidencing a selective encapsulation of the VOs constituents. The effects of processing conditions on moisture content, water activity, and particle size were negligible. The reported results suggest the feasibility of the complexation protocols proposed to manufacture novel binary and ternary complexes of βCD and chitosan.