*5.4. Complexation*

Encapsulation by complexation usually refers to the applied use of oligosaccharides such as cyclodextrins, specifically β-cyclodextrin, which are often used to encapsulate low polar substances such as essential oils. β-cyclodextrin, a cone-shaped molecule, comprises a network of compounds with 7 D-glucose α-1,4 glycosidic bonds. This structure allows essential oils to dissolve well in water and aids in fixing low-polarity substances and controlling evaporation [121]. The inclusion complex is said to increase the stability of the essential oils, particularly when exposed to sunlight [122].

## *5.5. Ionic Gelation*

Essential oil encapsulation using the ionic gelation technique uses charged polymers with essential oils to form the solution. It is then moulded by dripping it into a crosslinking solution. Sodium alginate is a low-cost polymer often used to encapsulate essential oils due to its biocompatibility and biodegradability [123]. This alginate microsphere provides a protective structure from environmental factors such as volatilisation or oxidation. As for food, it facilitates the mobility of the essential oil into the animal digestive system [124].
