Otimização do processo de obtenção do óleo essencial de folhas frescas e secas, de Capim-annoni-2 (Eragrostis plana Nees) por hidrodestilação

Abstract

Essential oils are volatile substances, usually a complex mixture of hydrocarbons, terpenes, alcohols and carbonyl compounds, which has been studied over the last years with the aim of identifying new chemicals and apply them in industry. In the process of obtaining essential oils regarded as the method of application and greater economic feasibility is hydrodistillation. The Eragrostis Plana Nees is a poaceae, tropical, perennial, summer, with attributes of invasive plant accidentally introduced in Brazil. The objective of the study was to optimize the extraction process of essential oil of fresh and dried leaves of Eragrostis Plana Nees, via hydrodistillation and evaluate its chemical composition. The plant material (leaves) was collected at the Experimental Station of UTFPR - Campus Pato Branco. The sheets were dried at room temperature for different time periods. There was a 24 factorial design of experiments proposed, taking into account four variables (drying time, amount of biomass, extraction time and size of biomass), the samples were subjected to hydrodistillation with a Clevenger apparatus, being centrifuged and the hidrolact essential oil obtained analyzed by GC/MS. It was found that the drying time was the only significant variable in the process, and, after 24 hours of drying, obtain the best yield of essential oil. Regarding the composition of the oil showed that the main compounds found in the essential oil of Eragrostis plana Nees were: 2-6-di-terc-butil – hidróxi-4-metil-benzeno (15,50%), 1,6,7,8-tetrahidro-1,6-dimetil-4-oxo - 4H-pirido [1,2-a] - pirimidina-3-carboxamida (16,02%) and 2,4-bis-(terc-butil)-6-metil – fenol (16,75%).