Extraction of volatile oils

basic methods of extraction of volatile oils

1. EXTRACTION OF VOLATILE OILS

2. Volatile oil production can be divided into 3 major ways. 1.Distillation 2.Solvent Extraction 3.Mechanical expression

3. 1.Distillation a) Distillation by water: It is applied to plants which are not injured upon boiling. Crude drug is introduced into the distillation chamber along with water and subjected to heat below 40 C . A mixture of oil and water is obtained as a distillate which is collected in a flask. Distillation plant for small amounts in the laboratory we can do it by using a set made of glass called a “ Clevenger type apparatus”.

4. b) Steam distillation : For substances which are usually injured by direct heat . Dried drug ground and covered with layer of water. Steam is passes through mixture , steam is generated by another chamber and piped into container having drug. The vapour contain vol. oils are introduced in condensing chamber cooled and collected.

5. 2.Solvent Extraction: a) solvent extraction  By soaking the plant in pure solvent . Filter the solvent soaked the plant out . Evaporative distillation at low temperatures under pressure. The rest of the concrete washed with alcohol several times to remove other contaminants out.

6. b ) Enfleurage method: is used for extraction of delicate perfumes . In this method , layer of fat is spread over a glass plate and flower petal are placed over fat layer which absorbs v.o . The exchausted petals are replaced by fresh petals . This process continues till the fatty layer is saturated volatile principle which are then extracted with lipid solvent this process can be done either hot or cold condition. c) Supercritical Fluid Extraction (SFE)

7. Expression: Expression can be used with plants such as orange peel, lemon oil glands. This method does not require heat. Ecuelle Method Ecuelle method is used for the extraction of citrus oils where oils cells in rind are ruptured mechanically using pointed projections by twisting raw material over them in clockwise direction either mechanically or manually.