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In the present study, the effect of S-cyclodextrin (beta-CD) and 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the antioxidant activity and storage stability of the essential oils (EOs) from Lavandula viridis, Lavandula pedunculata subsp. Iusitanica 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-beta-CD (i.e., 1900 mu moI(TE)/g(EO)). Moreover, the antioxidant activity of the EO/HP-beta-CD complexes was found to be considerably stable over 30 days, at 4 degrees C, possibly due to the higher solubility of the modified beta-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.

Lavanders (Lavandula spp.) are aromatic plants with high industrial and commercial value, used in food industry, perfumery and pharmaceutical preparations. Micropropagation can be used for large-scale multiplication of essential oil producing plants thus avoiding an overexploitation of natural resources. This work aims to develop a reliable protocol for the in vitro propagation of Lavandula pedunculata and to evaluate the potential of these plants for essential oil production with industrial application. In vitro cultures were established on media with different concentrations of benzyladenine. Trichome morphology was examined by SEM and their secretion analyzed by histochemical tests. Essential oils were isolated by hydrodistillation and analyzed by GC and GC-MS. The essential oils and trichomes of in vitro plants were compared with those of field-growing plants. Best propagation rates were achieved with 0.25 mg/l BA. Rooting occurred without treatment with auxins thus preventing callus growth. Trichomes and essential oils of the in vitro propagated plants were similar to those of the parent plants. Two chemotypes were characterized: 1,8-cineole/camphor type and fenchone type. Since trichomes and essential oils of L. pedunculata micropropagated plantlets are identical to those produced by field-growing plants, in vitro cultures can be used for essential oil production without affecting natural resources. Moreover, the quality of the essential oils is assured and this protocol can be further applied to the propagation of selected chemotypes for industrial purposes.