ABSTRACT
Patchouli is an aromatic species belonging to the Lamiaceae family that has essential oil with high commercial value to the hygiene, cosmetic and perfume industries. Considering its volatile characteristics and storage structures in different organs of aromatic plants, the determination of drying methods is extremely important and can affect both the yield and the composition of the essential oil. This work aimed to evaluate the content and composition of the patchouli essential oil after drying it in different periodin an oven and at room temperature. The trial was carried out in February 2011 at an experimental design completely randomized in 2X6 factorial scheme, corresponding to two drying methods (oven at 65˚C and room temperature) and six periods of essential oil extraction after harvest (0, 2, 4, 6, 8, and 10 days after harvest), with three replications. The essential oil was extracted by hydrodistillation in a Clevenger apparatus and the essential oil components were analyzed by gas chromatography coupled to mass spectrometry. There was significant interaction among the methods and drying times for both the content as well as for the composition of essential oil. The drying of the plants for two days in an oven at 65˚C increased the essential oil content; after this period, there was a significant reduction. For the leaves that dried at room temperature, their contentof essential oil was superior at the fourth and sixth days after the harvest. When comparing the methods, the drying in the oven was more efficient, with the oil content being significantly higher after two days of drying. After this period, however, there was a drastic reduction in the essential oil content, lower than the one observed in all periods when the leaves dried at room temperature. The different methods and drying periods also altered the essential oil`s composition. Although drying in oven at 65˚ for two days did not result in reduction of the contents of patchoulol and pogostol, higher contents were observed after six or eight days of drying. When drying was carried out at room temperature, no change in relative content of both components was observed.
Keywords
Pogostemoncablin (Blanco) Benth; Lamiaceae; drying; secondary metabolism; patchoulol; aromatic plants
