Extração e avaliação do óleo essencial de eucalipto de corte da espécie E. Grandis cultivado na região oeste do Paraná

Abstract

Eucalyptus has different applications, from the trunk to the leaves, being used mainly as firewood, with wood being the most used in industries in the agricultural sector, for the production of thermal energy. Eucalyptus is chosen as a source of wood for firewood due to its rapid growth and for being a great producer of biomass. Thus, this study aims to evaluate the physical-chemical properties and the quality of the essential oil extracted from the leaves of E. grandis, cultivated for the use of wood, in the western region of Paraná. Essential oil can be extracted from the sustainable reuse of leaves, collected during growth or felling of trees for use in wood. The essential oil extraction was performed by hydrodistillation, in a Clevenger apparatus, from dry and green leaves, at different times (60, 90 and 120 min). In order to identify some of the physical-chemical properties of the oils obtained, the refractive index and the absolute density were determined. Analysis by Gas Chromatography with Flame Ionization Detector (GC/FID) was also carried out to characterize the chemical composition of the product obtained. With regard to the yield of extractions, the values were higher for extractions with longer duration and lower moisture content in the leaves, but different data were obtained from those found in the literature, with the best yield obtained from extractions with dry leaves, containing only 10.8% moisture and performing 120 min of extraction (1.63%). For the density determination analysis and refractive index, the values obtained are similar to the data found in the literature, being 0.910 g cm-3 and 1.4756 for the essential oil obtained from fresh leaves, and 0.908 g cm-3 and 1.4739 for the essential oil obtained from dried leaves, respectively. From the chromatographic analyses, using the GC/FID technique, α-pinene (82.1 % in area for the essential oil obtained from dry leaves and 78.9 % in area for essential oil obtained from fresh leaves, both with 120 min of extraction) and 1,8-cineol (11.9 % in area for essential oil obtained from dried leaves and 12.7 % in area for the essential oil obtained from fresh leaves, both with 120 min of extraction).