Lavandin by-products development in a context of multifunctional agriculture: a case study in Tuscany

Hydrosols obtained during the steam distillation of essential oils have a much softer scent and lower toxicity to mammalians than the corresponding essential oils. They increasingly replace water in cosmetics and they are used also in the food factory for their antimicrobial and antioxidant properties. The main product from Lavandin (Lavandula x hybrida Balb. ex Ging.) consists in the essential oil obtained from flowering tops, and the corresponding hydrosol has been historically considered a by-product. However, there is an increasing interest in this natural derivative in terms of scien tific research and development of commercial products. Following this trend, hydrosols from Lavandin cultivated in a biodynamic farm in Tuscanu were obtained. Phytochemical profiles of the hydrosols obtained separately by the flowers and the styems, as well as the essential oils from the flowers, were acquired by GC-MS an ¹H-NMR analyses. Results indicated semi-quantitative differences between the major metabolites including linalool, 1,8-cineole, camphor, linalyl acetate, 4-terpineol, and borneol. Moreover, biological assays were also performed. In particular, germination tests of Raphanus sativus L. seeds showed that boyh Lavandin hydrosols and essential oils obtained from flowers completely inhibited the germination process; repellent activity against Tribolium confusum (Coleoptera Tenebrionidae) by the Area Preference Method showed a good repellency for both hydrosols extracts with RD₅₀ values of 3.6 and 3.3 μLcm⁻¹ for the flowers and stems, respectively. Within the farm, the development of further hydrosols from other plant species is in process and a dedicted manufacturing laboratory was implemented, allowing as well the development of specialised educational programs. The overall experience represents a valuable testimonial of multifunctional agriculture and applied research on medicinal and aromatic plants (MAPs), a favourable combination that could be better replicated under the new Italian regulation of this sector (DL 21 May 2018 n. 75).