Lemon Peel Oil

Lemon peel oil, usually simply called lemon oil, is the essential oil of the rind of the lemon fruit. Next to sweet orange oil it is the most important citrus oil, used widely in flavours and in perfumery; it smells fresh and strongly of lemon, and its main component is limonene. It is one of the citrus peel oils.

Type

Essential oil

Botanical name

Citrus limon

Other names

lemon oil

The fruit

The lemon is a small evergreen tree, a hybrid citrus, usually with sharp thorns on its twigs; it bears bright yellow fruits with a tart, acidic taste, and it may have originated in northern India. The oil comes from the coloured outer layer of the rind.

How the oil is made

Most lemon oil is pressed from the peel, by hand or by machine, either after the juice has been removed or before. Steam-distilled lemon oil is also sold. Some of it comes from the producers of concentrated lemon juice; it is of little importance for flavours and perfumes.

Composition

Limonene is usually 48 to 70% of lemon oil, and the citral components geranial and neral can reach about 2.9% and 1.5%, much more than in mandarin and related citrus oils. Other major components are beta-pinene, gamma-terpinene and alpha-pinene; the steam-distilled oil has a similar main composition.

Scent and uses

Pressed lemon oil has a light, fresh and sweet scent, truly reminiscent of the ripe peel, but it does not last long. Steam-distilled lemon oil smells softer, sweeter and less sharply zesty, and in a blend lemon oil is a top note with a strong initial scent.

In perfumery pressed lemon oil gives a refreshing, sweet-fruity note and is an important ingredient of the classic citrus colognes; it blends well with other citrus oils and with lavender, lavandin, petitgrain and neroli. It is widely used in flavours, and its masking effect is familiar from lemon served with fish: the peel oil covers the fishy smell. In aromatherapy the scent is described as energising and uplifting, and it is diffused to clear a room of cigarette smoke and other unpleasant smells.

Quality and storage

In the 1960s pressed lemon oil was frequently adulterated with distilled lemon oil, lemon terpenes, limonene, citral and other materials. Isotope analysis can reveal, for example, citral from lemongrass added to lemon oil.

Kept dark, cool, dry and with little air in the container, lemon oil can be stored for years without losing its fresh scent. Limonene oxidises easily, especially in warmth, and the oxidation products make the oil smell less fresh and raise the risk of a skin allergy.

Safety

Pressed lemon oil is phototoxic: on skin exposed to sunlight it can cause a reaction. At most 2% is recommended on the skin. Steam-distilled lemon oil is not phototoxic. Lemon oil of either kind should not be used on the skin once it has oxidised, and it may irritate the skin in some people.