Essential oils are also known as Ethereal or Volatile oils. They are odouriferous bodies of an oily nature derived from Vegetable sources. In India following essential oils are produced. Essential oils are produced in various internal and external glands of certain flowers, leaves, barks, wood and roots. Chemically these oils are mixtures, usually very complex, of terpenses, sesqui terpenes, their oxygenated derivatives, and other aromatic compounds. Many contain 20 to 30 constituents covering the entire range of organic materials.
Aromatic does not have the usual chemical meaning in the essential oil business. An aromatic chemical in this case, is any compound that has specific, useful odour. As old as the industry itself is the question of whether the plant gets any specific benefit from its essential oils. PROCESSES FOR EXTRACTION OF ESSENTIAL OIL.
Almost all essential oils
from various sources are extracted by distillation method. There are three types of distillation methods namely :-
1 Water distillation.
2 Water & Steam distillation.
3 Direct steam distillation.