About Lesson
Solvent extraction
- Based on extraction of the volatile oil from the plant material with a suitable solvent
- The method of solvent extraction process recovers almost all the oils and leaves behind only 0.5% to 0.7% residual oil in the raw material
- Useful for delicate flower oils that are present in very small amount and are not easily obtained by distillation or expression and are that are easily decomposed by heat.
Methods of solvent extraction
- According to the nature of the solvent used, three types are distinguished:
- Volatile solvent extraction
- Solvents used: petroleum ether & n-hexane
- Extraction (“percolation” or “maceration” at room temperature, “continuous hot extraction” in a Soxhlet apparatus at constant temperature).
- Solvent removal (distillation under reduced pressure)
- Non-volatile solvent extraction
- based on the liposolubility of volatile oils
- Used for Preparation of natural flower oils producing the finest perfumes.
- Supercritical fluid extraction
- Supercritical fluids provide a higher solubility of the components of the volatile oil, as well as improved mass-transfer rates.
- Moreover, the manipulation of parameters as temperature and pressure leads to the extraction of different components.