Bergamot essential oil is a cold-pressed

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...

produced by cells inside the rind of a

bergamot orange ''Citrus bergamia'', the bergamot orange (pronounced ), is a fragrant citrus fruit the size of an orange, with a yellow or green color similar to a lime, depending on ripeness. Genetic research into the ancestral origins of extant citrus cultiv ...

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

. It is a common

flavoring A flavoring (or flavouring), also known as flavor (or flavour) or flavorant, is a food additive used to improve the taste or smell of food. It changes the perceptual impression of food as determined primarily by the chemoreceptors of the gusta ...

and top note in perfumes. The scent of bergamot essential oil is similar to a sweet light orange peel oil with a floral note.

Production

The '' sfumatura'' or slow-folding process was the traditional technique for manually extracting the bergamot oil. By more modern methods, the oil is extracted mechanically with machines called peelers, which scrape the outside of the fruit under running water to get an

emulsion An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Althoug ...

channeled into centrifuges for separating the essence from the water. The rinds of 100 bergamot oranges yield about of bergamot oil.

Uses

Bergamot essential oil has been used in

cosmetics Cosmetics are constituted mixtures of chemical compounds derived from either natural sources, or synthetically created ones. Cosmetics have various purposes. Those designed for personal care and skin care can be used to cleanse or protect ...

aromatherapy Aromatherapy is based on the usage of aromatic materials including essential oils and other aroma compounds, with claims for improving psychological and physical well-being. It is offered as a complementary therapy or as a form of alternative m ...

, and as a flavoring in food and beverages. Its citrus scent makes it a natural flavoring and deodorizing agent. The volatile oils of the

are described as flavoring agents in the USP

Food Chemicals Codex The Food Chemicals Codex (FCC) is a collection of internationally recognized standards for the purity and identity of food ingredients. Scope The FCC features more than 1,250 monographs, including food-grade chemicals, processing aids, foods (suc ...

and are generally recognized as safe for human consumption by the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

. For example,

Earl Grey tea Earl Grey tea is a tea blend which has been flavoured with oil of bergamot. The rind's fragrant oil is added to black tea to give Earl Grey its unique taste. Traditionally, Earl Grey was made from black teas such as Chinese keemun, and there ...

is a type of

black tea Black tea, also translated to red tea in various East Asian languages, is a type of tea that is more oxidized than oolong, yellow, white and green teas. Black tea is generally stronger in flavour than other teas. All five types are made from ...

that may contain bergamot essential oil as a flavoring agent. Historically, bergamot essential oil was an ingredient in

Eau de Cologne Eau de Cologne (; German: ''Kölnisch Wasser'' ; meaning "Water from Cologne"), or simply cologne, is a perfume originating from Cologne, Germany. Originally mixed by Johann Maria Farina (Giovanni Maria Farina) in 1709, it has since come to be a ge ...

, a perfume originally concocted by

Johann Maria Farina Johann Maria Farina 1685–1766 Giovanni Maria Farina (born 8 December 1685, Santa Maria Maggiore; Germanized name: Johann Maria Farina, Francized: Jean Marie Farina – 25 November 1766, Cologne) was an Italian-born perfumier in German ...

at the beginning of the

18th century The 18th century lasted from January 1, 1701 ( MDCCI) to December 31, 1800 ( MDCCC). During the 18th century, elements of Enlightenment thinking culminated in the American, French, and Haitian Revolutions. During the century, slave trad ...

. The first record of bergamot oil used as a fragrance in perfume is from 1714, found in the Farina Archive in

Cologne Cologne ( ; german: Köln ; ksh, Kölle ) is the largest city of the German western States of Germany, state of North Rhine-Westphalia (NRW) and the List of cities in Germany by population, fourth-most populous city of Germany with 1.1 m ...

Constituents

A clear liquid (sometimes there is a deposit consisting of waxes) in color from green to greenish yellow, bergamot essential oil consists of a volatile fraction (average 95%) and a non-volatile fraction (5% or residual). Chemically, it is a complex mixture of many classes of organic substances, particularly in the volatile fraction, including

terpenes Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n > 1. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predominantly by plants, particularly conifers. Terpenes ar ...

esters In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are ...

alcohols In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl () functional group bound to a saturated carbon atom. The term ''alcohol'' originally referred to the primary alcohol ethanol (ethyl alcohol), which is ...

and

aldehydes In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group ...

, and for the non-volatile fraction, oxygenated

heterocyclic compound A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...

s as

coumarins Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by a lactone-like chain , forming a second six-membered h ...

and

furanocoumarin The furanocoumarins, or furocoumarins, are a class of organic chemical compounds produced by a variety of plants. Most of the plant species found to contain furanocoumarins belong to a handful of plant families. The families Apiaceae and Rutacea ...

Volatile fraction

The main compounds in the oil are

limonene Limonene is a colorless liquid aliphatic hydrocarbon classified as a cyclic monoterpene, and is the major component in the oil of citrus fruit peels. The -isomer, occurring more commonly in nature as the fragrance of oranges, is a flavoring ag ...

linalyl acetate Linalyl acetate, an organic compound, is the acetate ester of linalool. phytochemical found in many flowers and spice plants. It is one of the principal components of the essential oils of bergamot and lavender. It often occurs together with ...

linalool Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of ...

, γ-

terpinene The terpinenes are a group of isomeric hydrocarbons that are classified as monoterpenes. They each have the same molecular formula and carbon framework, but they differ in the position of carbon-carbon double bonds. α-Terpinene has been isolate ...

and β-pinene, and in smaller quantities

geranial Citral is an acyclic monoterpene aldehyde, and being a monoterpene, it is made of two isoprene units. Citral is a collective term which covers two geometric isomers that have their own separate names; the ''E''-isomer is named geranial (''trans' ...

and β- bisabolene.

Non-volatile fraction

The main non-volatile compounds are coumarins (

citropten Citropten is a natural organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), ...

, 5-geranyloxy-7-methoxycoumarin) and furanocoumarins (

bergapten Bergapten (5-methoxypsoralen) is a naturally-occurring organic chemical compound produced by numerous plant species, especially from the carrot family Apiaceae and the citrus family Rutaceae. For example, bergapten has been extracted from 24 ...

bergamottin Bergamottin (5-geranoxypsoralen) is a natural furanocoumarin found in the pulp of pomelos and grapefruits. It is also found in the peel and pulp of the bergamot orange, from which it was first isolated and from which its name is derived. Chemis ...

Adulteration

Comparison_of_bergamot_oils_using_GC-MS_analysis_with_enantiomeric_column

The bergamot essential oil is particularly subject to

adulteration An adulterant is caused by the act of adulteration, a practice of secretly mixing a substance with another. Typical substances that are adulterated include but are not limited to food, cosmetics, pharmaceuticals, fuel, or other chemicals, that ...

being an essential oil produced in relatively small quantities. Generally adulteration is to "cut" the oil, i.e. adding distilled essences of poor quality and low cost, for example of

bitter orange Bitter orange, Seville orange, bigarade orange, or marmalade orange is the citrus tree ''Citrus'' × ''aurantium'' and its fruit. It is native to Southeast Asia and has been spread by humans to many parts of the world. It is probably a cross bet ...

and bergamot mint and/or mixtures of terpenes, natural or synthetic, or "reconstruct" the essence from synthetic chemicals, coloring it with

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to a ...

. Worldwide, each year, around three thousand tonnes of declared essence of bergamot are marketed, while the genuine essence of bergamot produced annually amounts to no more than one hundred tons. Natural source analysis based on the

Carbon-14 Carbon-14, C-14, or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and coll ...

method can identify adulterated essences by detecting synthetic chemicals manufactured from petroleum that are used to mimic the chemical profile of bergamot oil and other essential oils.

Gas chromatography Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, ...

with columns having a chiral stationary phase allows analyzing mixtures of

enantiomer In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical ant ...

s. The analysis of the enantiomeric distribution of various compounds, such as linalyl acetate and linalool, allows the characterization of the bergamot oil according to the manufacturing process and allows for the detection of possible adulteration. The combined use of isotope ratio mass spectrometry and SNIF-NMR (Site-Specific Natural Isotope Fractionation-Nuclear Magnetic Resonance) allows discovering adulteration otherwise undetectable even allowing for the identification of the geographical origin of the essential oil. The GC-C-IRMS (Gas Chromatography-Combustion – Isotope Ratio Mass Spectrometer) technique, the most recently used, allows obtaining similar results.

Reference analytical values

Analytical values take as reference for genuinity evaluation of bergamot essential oil by the '' Experimental Station for the Industry of the Essential oils and Citrus products'', in

Reggio Calabria Reggio di Calabria ( scn, label= Southern Calabrian, Riggiu; el, label= Calabrian Greek, Ρήγι, Rìji), usually referred to as Reggio Calabria, or simply Reggio by its inhabitants, is the largest city in Calabria. It has an estimated popul ...

, Italy.

Toxicity

The

phototoxic Phototoxicity, also called photoirritation, is a chemically induced skin irritation, requiring light, that does not involve the immune system. It is a type of photosensitivity. The skin response resembles an exaggerated sunburn. The involved chemi ...

effects of bergamot essential oil have been known for more than a century. In 1925, Rosenthal coined the term "Berloque dermatitis" (from the French word "breloque" meaning trinket or charm) to describe the pendant-like streaks of pigmentation observed on the neck, face, and arms of patients. Cited in Alikhan 2016. He was unaware that, in 1916, Freund had correctly observed that these pigmentation effects were due to sun exposure after the use of

, a perfume infused with bergamot oil. Cited in McGovern and Barkley 2000, section&nbs
Phytophotodermatitis
Use of bergamot

oil, followed by exposure to

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...

light (either sunlight or a

tanning bed Indoor tanning involves using a device that emits ultraviolet radiation to produce a cosmetic tan. Typically found in tanning salons, gyms, spas, hotels, and sporting facilities, and less often in private residences, the most common device is a ho ...

), has been reported to cause

phytophotodermatitis Phytophotodermatitis, also known as berloque dermatitis or margarita photodermatitis, is a cutaneous phototoxic inflammatory reaction resulting from contact with a light-sensitizing botanical agent followed by exposure to ultraviolet light (from ...

, Cited i
CIR 2013
a serious skin inflammation indicated by painful

erythema Erythema (from the Greek , meaning red) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not assoc ...

and bullae on exposed areas of the skin. In one case, six drops of bergamot aromatherapy oil in a bath followed by 20–30 minutes exposure of ultraviolet light from a tanning bed caused a severe burn-like reaction. Cited i
CIR 2013
Epikutanni-test

Bergamot essential oil contains a significant amount of

, a phototoxic substance that gets its name from the

. Bergapten, a linear

derived from

psoralen Psoralen (also called psoralene) is the parent compound in a family of naturally occurring organic compounds known as the linear furanocoumarins. It is structurally related to coumarin by the addition of a fused furan ring, and may be considered a ...

, is often found in plants associated with phytophotodermatitis. Note that bergamot essential oil has a higher concentration of bergapten (3000–3600 mg/kg) than any other ''Citrus''-based essential oil. When bergamot essential oil is applied directly to the skin via a patch test, followed by exposure to

light, a concentration-dependent

effect is observed. However, if the oil is twice rectified (and therefore bergapten-free), no phototoxic response is observed. Cited i
CIR 2013
The International Fragrance Association (IFRA) restricts the use of bergamot essential oil due to its phototoxic effects. Specifically, IFRA recommends that leave-on skin products be limited to 0.4% bergamot oil, which is more restrictive than any other ''Citrus''-based essential oil. Although generally recognized as safe for human consumption, bergamot essential oil contains a significant amount of

, one of two furanocoumarins believed to be responsible for a number of

grapefruit–drug interactions Some fruit juices and fruits can interact with numerous drugs, in many cases causing adverse effects. The effect is most studied with grapefruit and grapefruit juice, but similar effects have been observed with certain other citrus fruits. The ...

. In one case study, a patient who consumed four liters of Earl Grey tea per day suffered

paresthesia Paresthesia is an abnormal sensation of the skin (tingling, pricking, chilling, burning, numbness) with no apparent physical cause. Paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes. Paresthesias ar ...

fasciculation A fasciculation, or muscle twitch, is a spontaneous, involuntary muscle contraction and relaxation, involving fine muscle fibers. They are common, with as many as 70% of people experiencing them. They can be benign, or associated with more serio ...

s and muscle cramps.

Notes

Bibliography

* * * *Alp Kunkar and Ennio Kunkar, "Bergamotto e le sue essenze", Edizioni A Z *A. Kunkar, C. Kunkar: Supercritical CO2 extraction of bergamot oil from peel ; Int. Cong. Medicinal plants and essential oils- Anadolu üniversıtesi-Eskişehir Turkey

External links

* *{{cite web, last=Committee on Herbal Medicinal Products (HMPC), title=List of references supporting the assessment of Citrus bergamia Risso et Poiteau, aetheroleum Final, url=http://www.ema.europa.eu/docs/en_GB/document_library/Herbal_-_List_of_references_supporting_the_assessment_report/2012/08/WC500131464.pdf, publisher= European Medicines Agency (EMA), date= 22 May 2012, access-date=7 April 2014 Essential oils