Frankincense



Frankincense (also known as olibanum, לבונה, اللبان al-libān or البخور al-bakhūr) is an aromatic resin used in incense and perfumes, obtained from trees of the genus Boswellia in the family Burseraceae, particularly Boswellia sacra (syn. B. bhaw-dajiana), B. carterii, B. frereana, B. serrata (B. thurifera, Indian frankincense), and B. papyrifera. The word is from Old French franc encens ('high-quality incense').

There are five main species of Boswellia that produce true frankincense. Resin from each of the five is available in various grades, which depend on the time of harvesting. The resin is hand-sorted for quality.

Etymology
The English word frankincense derives from the Old French expression franc encens, meaning "high-quality incense". The word in Old French meant "noble" or "pure".

A popular folk etymology suggests a connection with the Franks (and often in particular Frankish Crusaders), who reintroduced the spice to Western Europe during the Middle Ages, but the word itself comes from the expression.

Description


Frankincense is tapped from the scraggly but hardy trees by striping (slashing the bark) and letting the exuded resin bleed out and harden. The hardened streaks of resin are called tears. Several species and varieties of frankincense trees each produce a slightly different type of resin. Differences in soil and climate create even more diversity of the resin, even within the same species.

Boswellia sacra trees are considered unusual for their ability to grow in environments so unforgiving that they sometimes grow out of solid rock. The initial means of attachment to the rock is unknown, but is accomplished by a bulbous disk-like swelling of the trunk. This growth prevents violent storms from detaching the tree. This feature is slight or absent in trees that grow in rocky soil or gravel.

The trees start producing resin at about eight to 10 years old. Tapping is done two to three times a year with the final taps producing the best tears due to their higher aromatic terpene, sesquiterpene and diterpene content. Generally speaking, the more opaque resins are the best quality. Fine resin is produced in Somalia, from which the Roman Catholic Church purchases most of its stock.

Recent studies indicate that frankincense tree populations are declining, partly due to over-exploitation. Heavily tapped trees produce seeds that germinate at only 16% while seeds of trees that had not been tapped germinate at more than 80%. In addition, burning, grazing, and attacks by the longhorn beetle have reduced the tree population. Conversion (clearing) of frankincense woodlands to agriculture is also a major threat.

Chemical composition


These are some of the chemical compounds present in frankincense: See the following references for a comprehensive overview of the chemical compounds in different frankincense species.
 * acid resin (6%), soluble in alcohol and having the formula C20H32O4
 * gum (similar to gum arabic) 30–36%
 * 3-acetyl-beta-boswellic acid (Boswellia sacra)
 * alpha-boswellic acid (Boswellia sacra)
 * incensole acetate, C21H34O3
 * phellandrene

History


Frankincense has been traded on the Arabian Peninsula for more than 6,000 years. Its use was characteristic in religious rites throughout Mesopotamia and the Eastern Mediterranean from the earliest antiquity.

Frankincense was reintroduced to Europe by Frankish Crusaders, although its name refers to its quality, not to the Franks themselves. Though it is better known as "frankincense" to westerners, the resin is also known as olibanum, or in Arabic al-lubān (, roughly translated: "that which results from milking"), a reference to the milky sap tapped from the Boswellia tree.

The Greek historian Herodotus was familiar with frankincense and knew it was harvested from trees in Southern Arabia. He reported that the gum was dangerous to harvest because of venomous snakes that lived in the trees. He goes on to describe the method used by the Arabs to get around this problem, that being the burning of the gum of the styrax tree whose smoke would drive the snakes away. Theophrastus mentions the resin, as does Pliny the Elder in his Naturalis Historia.

Southern Arabia was a major exporter of frankincense in antiquity, with some of it being traded as far as China. The 13th-century Chinese writer and customs inspector Zhao Rugua wrote on the origin of frankincense, and of its being traded to China:

"Ruxiang or xunluxiang comes from the three Dashi [Arab] countries of Murbat (Maloba), Shihr (Shihe), and Dhofar (Nufa), from the depths of the remotest mountains. The tree which yields this drug may generally be compared to the pine tree. Its trunk is notched with a hatchet, upon which the resin flows out, and, when hardened, turns into incense, which is gathered and made into lumps. It is transported on elephants to the Dashi (on the coast), who then load it upon their ships to exchange it for other commodities in Sanfoqi. This is the reason why it is commonly collected at and known as a product of Sanfoqi."

Quality


Frankincense comes in many types, and its quality is based on color, purity, aroma, age, and shape. Silver and Hojari are generally considered the highest grades of frankincense.

Currently, two dissertations describe how to identify a few olibanum species according to specific secondary metabolism products.

Production
Thousands of tons of frankincense are traded every year to be used in religious ceremonies as incense in thuribles and by makers of perfumes, natural medicines, and essential oils. It can be inhaled or applied to the skin for its supposed health benefits. Most frankincense comes from North Africa and India, but also in Oman, Yemen, and western Africa.

In Somaliland, a self-governing region northwest of Somalia that is not recognized by foreign governments, frankincense is harvested in the Sanaag and Bari regions: mountains lying at the northwest of Erigavo; El Afweyn District; Cal Madow mountain range, a westerly escarpment that runs parallel to the coast; Cal Miskeed, including Hantaara and Habeeno plateau and a middle segment of the frankincense-growing escarpment; Karkaar mountains or eastern escarpment, which lies at the eastern fringe of the frankinscence escarpment. In Dhofar, Oman, frankincense species grow north of Salalah and were traded in the ancient coastal city of Sumhuram, now Khor Rori.

Ecological status
In 1998, the International Union for Conservation of Nature (IUCN) warned that one of the primary frankincense species, Boswellia sacra, is "near threatened". Frankincense trees are not covered by the Convention on International Trade in Endangered Species of Wild Fauna and Flora, but experts argue that Boswellia species meet the criteria for protection. In a 2006 study, an ecologist at Wageningen University & Research claimed that, by the late-1990s, Boswellia papyrifera trees in Eritrea were becoming hard to find. In 2019, a new paper predicted a 50% reduction in Boswellia papyrifera within the next two decades. This species, found mainly in Ethiopia, Eritrea, and Sudan, accounts for about two-thirds of global frankincense production. The paper warns that all Boswellia species are threatened by habitat loss and overexploitation. Most Boswellia grow in harsh, arid regions beset by poverty and conflict. Harvesting and selling the tree's resin is one of the only sources of income for the inhabitants, resulting in overtapping.

Uses
Frankincense is used in perfumery and aromatherapy. It is also an ingredient that is sometimes used in skincare. The essential oil is obtained by steam distillation of the dry resin. Some of the smells of the frankincense smoke are products of pyrolysis.

In Chinese medicine, it (ru xiang) along with myrrh (mo yao) have anti-bacterial properties as well as blood-moving uses. It can be used topically or orally. The Egyptians cleansed body cavities in the mummification process with frankincense and natron. In Persian medicine, it is used for diabetes, gastritis and stomach ulcer.

Frankincense is used in many Christian churches, including the Eastern Orthodox, Oriental Orthodox, and Catholic churches. According to the Biblical text of Matthew 2:11, gold, frankincense, and myrrh were among the gifts to Jesus by the biblical magi "from out of the East." Christian and Islamic Abrahamic faiths have all used frankincense mixed with oils to anoint newborn infants, initiates and members entering into new phases of their spiritual lives.

The spread of Christianity depressed the market for frankincense during the 4th century AD. Desertification made the caravan routes across the Rub' al-Khali ("Empty Quarter") of the Arabian Peninsula more difficult.

Essential oil
The essential oil of frankincense is produced by steam distillation of the tree resin. The oil's chemical components are 75% monoterpenes, sesquiterpenes, monoterpenoles, sesquiterpenols and ketones. Contrary to some commercial claims, steam distilled frankincense oils do not contain the insufficiently volatile boswellic acids (triterpenoids), although they may be present in solvent extractions. The chemistry of the essential oil is mainly monoterpenes and sesquiterpenes, such as alpha-pinene, Limonene, alpha-Thujene, and beta-Pinene with small amounts of diterpenoid components being the upper limit in terms of molecular weight.

Perfume
Olibanum is characterised by a balsamic-spicy, slightly lemon, fragrance of incense, with a conifer-like undertone. It is used in the perfume, cosmetic and pharmaceutical industries.