Gorka pomorandža

The tree and its fruit

The bitter orange, also called sour orange, Seville orange or bigarade orange, is the hybrid citrus tree species 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 a cross between the pomelo, Citrus maxima, and the wild type mandarin orange, Citrus reticulata. The peel of Citrus aurantium is thick, richer in pectin than sweet orange peel, and holds more essential oil than the peel of other Citrus species. The tree is generally used as a rootstock, and it resists several viral diseases and tolerates cold. The raw pulp is not usually eaten. The Seville orange is used to make British orange marmalade, being higher in pectin than the sweet orange and therefore giving a better set and a higher yield.

One tree, several oils

Neroli is distilled from the blossoms of the tree, and petitgrain from its leaves and sometimes the twigs and branches. Petitgrain bigarade oil is distilled from the same botanical species as neroli and bitter orange essential oil, yet it has a unique aroma of its own. Neroli oil smells sweet, honeyed and somewhat metallic, with green and spicy facets. Tunisia, Morocco and Egypt are the leading producers of neroli. The main regions of production of petitgrain are Paraguay and France. Distillation of the flowers gives orange blossom water at 99.9% and neroli oil at only 0.1% of the distillation products.

Chemistry

In a study of trees growing in Northern Greece, the peel oil was made up almost entirely of monoterpene hydrocarbons (98.30%), mainly limonene. In that study the main compounds of the peel oil were limonene (94.67%), myrcene (2.00%), linalool (0.76%), β-pinene (0.62%) and α-pinene (0.53%). In a Tunisian study, limonene was the major volatile compound of the peel, at 90%. In Italian peel, monoterpene hydrocarbons made up 72.5% and oxygenated monoterpenes 7%, with limonene the major component at 66%. Petitgrain bigarade oil contains linalyl acetate (45%) and linalool (20%) among its main components.

Uses in food and drink

In many countries an oil is pressed from the fresh peel of ripe fruit and used in ice creams, puddings, sweets, soft and alcoholic drinks, and pharmaceuticals.

Safety and storage

Bitter orange oil carries a low risk of phototoxicity, while neroli and petitgrain oils are not phototoxic. Bitter orange oil was neither irritating nor sensitizing to 25 volunteers when tested at 10%. The oil is kept in a cool, dry place in tightly sealed containers, protected from heat and light.