8016-36-2

Olibanum is a gum resin secreted by several Boswellia species that grow extensively from South Arabia to Somaliland. The small trees or shrubs yield an exudate after incisions are made on the bark; it consists of a milky liquid that hardens into small, yellowish droplets commercially known as incense tears. The tears are sorted; the most valuable quality (white tears) is sold as burning incense, while the less valuable qualities (powder and fragments) are used in flavors and perfumes because of their more reasonable cost. The part used is the gum resin exudate.

Olibanum oil and olibanum resinoid are obtained from frankincense, which is a gum resin collected from the bark of the tree Boswellia carteri Birdw. or Boswellia frereana Birdw. (Burseraceae) growing in Arabia and Somalia. The resinoid is produced by solvent extraction, and steam distillation gives the oil, which is a pale yellow, slightly viscous liquid with a balsamic odor and a faint lemon note.
d²⁵₂₅ 0.862–0.889; n²⁰_D 1.4650–1.4820; α²⁰_D ?15 ° to +35 °; solubility: 1 vol in 6 vol of 90% ethanol, solutions occasionally opalescent; acid number: max. 4.0; ester number: 4–40.
Various qualities are commercially available. Their compositions may vary considerably because they are prepared from the resins of different Boswellia species. Main constituents of the oil are monoterpene hydrocarbons.
Olibanumoil and resinoid are used in oriental-type perfumes, the resinoid especially for its good fixative properties.

The oil, obtained by steam distillation of the trees B. carterii Birdw. and other Boswellia species, has a balsamic, slightly citrine odor.

It is a pale-yellow liquid. It is soluble in most fixed oils and with a slight haze in mineral oil. It is insoluble in propylene glycol and glycerin.

Extractives and their physically modified derivatives. Boswellia, Burseraceae.