Бергамот

Bergamot, Citrus bergamia, is a fragrant citrus fruit the size of an orange, yellow or green in colour depending on ripeness. It is defined as a hybrid of bitter orange and lemon and belongs to the Rutaceae family. The trees have big dark green ovate leaves similar to those of lemon, star-shaped white flowers and round yellow fruits. The fruit turns from green to yellow as it ripens, with a sour, bitter pulp.

Origin and production

The bergamot is a citrus fruit grown mostly in Mediterranean areas. Production is on large scale in the Ionian Sea coastal areas of the province of Reggio di Calabria in Italy. Ninety per cent of the world's production of bergamot oil is sourced from crop to factory in Calabria. Three cultivars are traditionally grown: Feminello, Fantastico and Castagnaro. Bergamot is also grown in southern France and the Ivory Coast for the essential oil, and in Antalya in southern Turkey for its marmalade. Around 1,300 smallholder farmers in Calabria work on the bergamot trees. Harvesting begins with the arrival of cold days at the end of November and usually ends around the end of February. It takes four to five years for a bergamot tree to bear fruit, with each tree producing around 100 kilograms per year, and two trees to produce a single kilogram of essential oil.

Chemistry

Bergamot essential oil consists of a volatile fraction (average 95%) and a non-volatile fraction (5% or residual). It is a complex mixture of many classes of organic substances, particularly in the volatile fraction, including terpenes, esters, alcohols and aldehydes. The non-volatile fraction holds oxygenated heterocyclic compounds such as coumarins and furanocoumarins. The main volatile components are limonene (30–45%), linalyl acetate (22–36%), linalool (3–15%), γ-terpinene (6–10%) and β-pinene (4.5–9%). The (−) enantiomer makes up 99.3 to 99.7% of the linalool and 99.4 to 99.7% of the linalyl acetate. Of the limonene, 97.4 to 98.4% is the (+) enantiomer. Bergapten, found in the non-volatile residue, is present at 1800 to 3800 mg/kg.

Phototoxicity and FCF

Bergamot essential oil contains a significant amount of bergapten, a phototoxic substance that gets its name from the bergamot orange. Bergapten is a linear furanocoumarin derived from psoralen, often found in plants associated with phytophotodermatitis. Bergamot essential oil has a higher concentration of bergapten than any other Citrus-based essential oil. When the oil is applied directly to the skin in a patch test and followed by exposure to ultraviolet light, a concentration-dependent phototoxic effect is observed. If the oil is twice rectified, and therefore bergapten-free, no phototoxic response is observed. The oil also contains a significant amount of bergamottin, one of two furanocoumarins believed to be responsible for a number of grapefruit-drug interactions. IFRA recommends that leave-on skin products be limited to 0.4% bergamot oil. This is more restrictive than for any other Citrus-based essential oil.

Uses

Bergamot essential oil has been used in cosmetics, aromatherapy, and as a flavoring in food and beverages. An essence extracted from the aromatic skin of the fruit flavours Earl Grey and Lady Grey teas, as well as confectionery. The pharmaceutical industry uses it to absorb the unpleasant smells of medicinal products and for its antiseptic and antibacterial properties. Clinical studies of its therapeutic applications focus exclusively on aromatherapy and suggest that its use can help reduce anxiety and stress.

Quality control

Adulteration with cheaper products such as oil of rosewood and bergamot mint has been a problem for consumers. To protect the reputation of their produce, the Italian government introduced tight controls, including testing and certificates of purity. The Experimental Station for Essential Oil and Citrus By-Products in Reggio di Calabria is the quality control body for the essential oil Bergamotto di Reggio Calabria DOP.