Essence itself have two kind, one natural essence that produce from plant and the others is synthetic essence that can be produced from chemical reaction. Synthetic essence often prohibited use for food because this essence type can cause cancer.
Most odorous substances used in perfumery come under three beadings:
- essential oils
- synthetic or semi-synthetic chemicals
Essential oils may be defined as volatile, odoriferous oils of vegetable origin. A distinction should be made, however, between natural flower oils obtained by effleurage or solvent extraction and essential oils recovered by distillation. Distilled oils may lack some component which is not volatile enough or which is lost during distillation. Two notable examples of this are rose oil, in which phenyl ethyl alcohol is lost to the watery portion of the distillate, and orange flower oil, in which the distillated oil contains but a very small proportion of methyl antbranilate, whereas the extracted flower oil may contain as much as one sixth of this constituent.