Cyclodextrins enhance the antioxidant activity of essential oils from three Lamiaceae species.

In the present study, the effect of β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) on the antioxidant activity and storage stability of the essential oils (EOs) from Lavandula viridis , Lavandula pedunculata subsp. lusitanica and Thymus lotocephalus (Lamiaceae) was investigated. The presence of both cyclodextrins (CDs) was found to produce a remarkable enhancement on the antioxidant activity as assessed by the oxygen radical absorbance capacity (ORAC) assay. The highest free radical-scavenging effect was observed in the EO from T. lotocephalus , particularly at the highest concentration of HP-β-CD (i.e., 1900 μmol TE /g EO ). Moreover, the antioxidant activity of the EO/HP - β-CD complexes was found to be considerably stable over 30 days, at 4 °C, possibly due to the higher solubility of the modified β-CD. The results obtained suggest that these systems can be a very interesting alternative as a natural source of antioxidants for different applications such as in the food preservation field. [ABSTRACT FROM AUTHOR]