Fractionation of rosemary (Rosmarinus officinalis L.) essential oil using vacuum fractional distillation.

Rosemary essential oil has many compounds suitable for use in the food, cosmetics and pharmaceuticals industries. This study aimed to evaluate vacuum fractional distillation to separate and purify components of rosemary oil, also to observe the distillation patterns. The light terpenes (α-pinene, myrcene, camphene) were removed at the top of the column, while the oxygen containing components (verbenone, borneol, linalool, geraniol) remained at the bottom. The concentrations of some minor compounds increased more than ten times (borneol, geraniol) compared with the raw oil. There was no evidence of thermal degradation in any of the experiments. Therefore, vacuum fractional distillation may be an interesting process to upgrade rosemary essential oil. © Association of Food Scientists & Technologists (India) 2019.