Isolation of rosemary oil: Comparison between hydrodistillation and supercritical CO₂ extraction

Abstract

Abstract Rosemary leaf oil was isolated by a supercritical fluid extraction (SFE) procedure coupled to a fractional separation following the extraction stage. The oil produced was compared with rosemary oil isolated by hydrodistillation. Chemical analysis revealed that, although roughly the same compounds were extracted, the two oils possessed a widely different percentage composition. Qualitative aroma testing showed that the oil obtained by SFE using CO 2 showed a fragrance that better resembled that of the rosemary leaves used for the isolation of the oil.