Influence of drying air temperature on the essential oil content from melaleuca alternifolia cheel.

The purpose of the present study is to evaluate the influence of drying air temperature on the essential oil content of sliced Melaleuca alternifólia Cheel. Three samples were taken randomly from each treatment and analyzed when still fresh in order to determine the moisture and essential oil contents. The samples were then cooled in the B.O.D at 2 °C till completion of the drying process. For the application of drying tests, an updraft fixed-bed dryer was used equipped with a liquefied petroleum gas (LPG) burner to heat up the drying air. The air velocity was 0.5 0.03 ms and the relative humidity at the dryer entrance was 65%. The drying air temperatures were 40, 50, 60, 70 and 80°C. Three replications of the drying tests were done; where 500 g of the sliced plant cut into 5 cm thick layers were used. The essential oil was extracted in three hours by means of a hydro-distillation method. No statistical differences were detected between the drying treatments; however, when compared to the fresh plant, a reduction of 18.19% in oil content was observed as compared to the dried samples under different temperatures.