FROM HARVESTING TO DISTILLATION – EFFECT OF ANALYTICAL PROCEDURES ON THE YIELD AND CHEMICAL COMPOSITION OF RHODODENDRON TOMENTOSUM (LEDUM PALUSTRE) ESSENTIAL OIL

Abstract: Rhododendron tomentosum possesses the anti-inflammatory, analgesic and antimicrobial properties, determined by the chemical composition of its essential oil. The effects of place (Miszewko, Lubichowo) and time of harvesting (June, November) as well as drying (air-drying, oven-drying, freeze-drying) and isolation (in Deryng, Clevenger and Likens-Nickerson apparatus) procedures on the yield and quality of R. tomentosum essential oil were studied. Ledol (8.1-14.4%), palustrol (6.9-13.0%) and γ-terpineol (8.5-9.1%) predominated in the plants collected from Miszewko, while γ-terpineol (11.8-22.2%), p-cymene (5.3-12.6%) and geranyl acetate (5.7-7.5%) prevailed in the biomass from Lubichowo. The shoots produced more volatiles in the flowering phase than in the end of the vegetation. Oven-drying at 30ºC with controlled air flow was suggested as the quick dehydration method. Hydrodistillation in Deryng and Clevenger apparatus resulted in comparatively high essential oil yield (about 1%). All studied drying and distillation methods did not influence significantly the general profile of R. tomentosum essential oil.