β-Cyclodextrin inclusion complexes of combined Moroccan Rosmarinus officinalis, Lavandula angustifolia and Citrus aurantium volatile oil: production optimization and release kinetics in food models

A combined volatile oil (VO) was extracted from Rosmarinus officinalis, Lavandula angustifolia and Citrus aurantium by simultaneous hydro- and steam-distillation, and encapsulated in beta-cyclodextrin by co-precipitation. Response surface methodology (RSM) was used to optimize microencapsulation conditions. The variable recovered powder, VO retention degree, and inclusion efficiency were investigated based on two factors: solid-to-liquid and liquid-to-liquid (ethanol/water) ratios. The responses were influenced by the concentration of ethanol in the reaction mixture and the amount of VO used. VO release from the inclusion complexes was investigated in 10% ethanol and in 3% acetic acid. The obtained data were fitted to the first-order Korsmeyer-Peppas, Higuchi, and Peppas-Sahlin models. The Higuchi model gave the fittest approach for the VO release profile in both cases, showing that the release mechanism was controlled by Fickian diffusion.

Automated summary

A combined volatile oil from Rosmarinus officinalis, Lavandula angustifolia and Citrus aurantium was encapsulated in beta-cyclodextrin using co-precipitation method. Response surface methodology was applied to optimize microencapsulation conditions and investigate the variables affecting the encapsulation process. The release of volatile oil from the inclusion complexes was studied using different solutions. The Higuchi model provided the best fit for the release profile, indicating Fickian diffusion as the predominant mechanism of release.