Comparative study of water volume and distillation time on Cananga essential oil profiles resulted from hydrodistillation and steam-water distillation by cohobation method

Abstract

This research aimed to investigate the effect of water volume and duration on two kinds of distillation methods, hydrodistillation and steam-water distillation, in a cohobation process. Essential oil profiles, including volatile compounds content, refraction indexes, and essential oil yields, were investigated. The essential oils were obtained from the flowers of Cananga odorata distilled in a modified kettle which can either be set as a steamer pot or just as a standard pan/boiler using cohobation method. Both distillation methods resulted in different yield and component trending of Cananga oils. The volume of water was varied into three conditions (15 L; 20 L; 25 L) on both distillation methods to optimize distillation since the water was required to extract essential oils continuously in a cohobation scheme. Two hours hydrodistillation of 1.5 kg Cananga flowers resulted in an optimum Cananga oil yield using 25 L of water (0.411 %). At the same time, steam- water distillation did not significantly influence the variation of the water amount in the kettle (0.289-0.383%). The effect of duration time of distillation on the Cananga oil’s profiles has also been investigated. Both distillation processes required seven hours of distillation to obtain more than 0.05% of Cananga oil in every hour of distillation. Both distillation trends showed a similar curve, representing an increase of essential oil production at the beginning of distillation up to three hours processes which then decline gradually in the next hour into the last seven hours of distillation. All Cananga oil products from both distillation methods have met the quality standard requirement for SNI 06-3949-1005 regarding refractive index value, color, and odor. Volatile components of Cananga oils obtained from both distillation methods were similar, including geranyl acetate, trans-caryophyllene, a-humulene, a-farnesene, benzyl benzoate, and germacrene-D, except for linalool which is only found in Cananga oil from steam-water distillation. However, Cananga oils from the hydrodistillation method showed better yield and quality than those from steam-water distillation in terms of oxygenated compounds and ester content.