Cyclodextrins for Essential Oils Applications
Résumé
here is a growing interest for the aromatic and biological properties of essential oils, as alternatives to synthetic chemicals. Nonetheless, essential oils and their components are poorly soluble in water, and are highly sensitive to degradation and evaporation. Encapsulation in cyclodextrins can reduce these drawbacks and improve the properties of essential oils. Cyclodextrins are non-toxic cyclic oligosaccharides obtained by enzymatic degradation of starch. Cyclodextrins inclusion complexes find applications in the food, pharmaceutical and cosmetic industries.
This chapter reviews encapsulation of essential oils in cyclodextrins. The strength of binding between cyclodextrins and essential oils components covers a wide range of formation constants with values ranging from 13 to 166,338 M−1. The encapsulation in cyclodextrins increases the aqueous solubility of essential oils up to 16-fold and reduces oil photodegradation rates up to 44-fold, while ensuring gradual release of oils. This chapter also discusses the effect of encapsulation on biological activities such as antimicrobial and antioxidant properties of essential oils. Biological effects depend on the nature and concentrations of essential oils and cyclodextrin, the tested microorganism, and other factors. Emerging cyclodextrin-based approaches for textiles and nanofibers are also discussed.