Kinetics of distillation of essential oil from comminuted ripe juniper (Juniperus communis L.) berries

The distillation of essential oil from comminuted ripe berries of Juniperus communis L. (juniper oil) was studied at different hydrodistillation rates. The distillation of juniper consisted of an initial, fast oil distillation followed by a slow oil distillation. Based on this mechanism, the kinetics of juniper oil distillation were described using a two-parameter model of unsteady-state diffusion through the plant material. The hydrodistillation rate and berries-to-water ratio were shown to affect the distillation rate, process duration, yield, composition and physical properties of the juniper oil. Both the fast distillation rate and the yield of juniper oil increased with increasing hydrodistillation rate. The fast oil distillation rate increased and the oil yield decreased somewhat with increasing berries-to-water ratio. The amount of alpha-pinene decreased and the amount of myrcene increased with increasing hydrodistillation rate.