A. Dobreva1*, M. Todorova2

1Institute for Roses and Aromatic Plants, Agricultural Academy, 6100 Kazanlak, Bulgaria
2Department of Plant Science, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 30June 2022; accepted for publication 4 August 2023)

Abstract. Bulgaria is known for its essential oils and medicinal plants, which occupy increasing parts in the agricultural areas. In recent years, the boom in lavender production has made our country the largest producer of lavender oil in the world. This intensified the scientific work with it and led to the creation of new lavender varieties and lines that are used in production. All research and tests on an industrial scale go through the laboratory distillation of small amounts of plant material to determine the quantity and quality of essential oil. In laboratory practice, micro-apparatus for water distillation is widely used, which does not reflect the real results for the yield and quality of the product. This necessitated the creation of a new laboratory device for determining the content of essential oil in raw materials with labile (rich in esters) oil by the application of steam distillation. The design of this apparatus mirrors industrial installations, thus the results it produces accurately simulate those of industrial production. Tests with herbal raw materials, like Lavandula angustifolia Mill., Salva sclarea L. and Helichrysum italicum (Roth) G. Don showed that the model is effective and applicable. The oils obtained by the new apparatus retained an ester content of 40.2%, 75.0% and 4.8%, respectively; these figures represent a significant improvement over previous methods.