Variação no rendimento e composição química do óleo essencial de folhas de atroveran (Ocimum selloi Benth.) inteiras e moídas sob condições de armazenamento

Abstract

Besides genetic and environmental characteristics, the cultivation and processing systems of medicinal plants are important factors in the product final quality. Among such factors, storage has been scarcely studied regarding medicinal plant conservation. The aim of this work was to study the effect of storage time on essential oil yield and chemical composition in the dry matter of whole and powdered Ocimum selloi leaves. The experiment consisted of two fragmentation treatments (whole and powdered leaf) and five storage times (0, 3, 6, 9, and 12 months). Dry leaves were packed in plastic bags, which were sealed and stored in a dry and dark place. The essential oil was extracted by hydrodistillation in modified Clevenger-type device and the chemical composition was analyzed through gas chromatography using a flame ionization detector attached to a mass spectrometer (GC-MS-FID). There was an accentuated reduction in the essential oil yield of powdered and whole leaves stored over one year, but the essential oil yield of whole leaves was significantly higher than that of powdered ones. In general, the major compound methyl-chavicol was higher in whole leaves than in powdered ones and decreased over the storage time. The fragmentation type and the storage time decisively interfere in O. selloi essential oil yield and composition.