What is "Citrus Reticulata Peel Oil" and what is its purpose?

The Citrus reticulata Blanco , or mandarin tree, is a species belonging to the Rutaceae family. It is a non-hybrid variety originating from China, cultivated for millennia for its fruit. The mandarin owes its name to its colour, reminiscent of the silk robes worn by the Mandarins, high-ranking officials of the Chinese Empire. The mandarin tree only arrived in Europe, particularly in Provence, around 1800, four hundred years after the orange, thanks to the Portuguese. It is now widely cultivated in the warm and sunny areas of the planet, especially around the Mediterranean (Algeria, Morocco, Spain, etc...).

Unlike many essential oils that are obtained through hydrodistillation, mandarin essence is extracted by first cold pressing of the pericarps of fresh fruits (zests). This process allows the preservation of the fruit's constituents, namely terpenes, such as limonene, the gamma-terpinene and linalool, aldehydes, including citronellal, citral and decanal, flavonoids and esters.

There are different types of mandarin essential oils: green, yellow, or red. Contrary to what we might think, these are not three different species of mandarin. There is only one, the Citrus reticulata Blanco. The difference lies in the degree of fruit maturity at the time of essential oil extraction and therefore the harvest period. Indeed, during the autumn, the mandarin is rich in chlorophyll, its pericarp is then green. As winter approaches, the chlorophyll gradually disappears and the mandarin takes on an orange colour, passing through yellow. They all have the same properties and uses ; the difference is in their colour, but also in their scent : the yellow mandarin has a softer, sweeter smell, while the green mandarin is more tangy.

When applied topically, mandarin essential oil is recognised for its properties purifying. By balancing sebum production, it prevents the appearance of skin imperfections, including blackheads and acne spots. The presence of monoterpenes also makes it an active ingredient against inflammation, which helps to soothe redness and tightness.

When applied to hair, "Citrus Reticulata Peel Oil" is used to "detoxify" the hair. Once purified, the hair fibres regain their flexibility and shine. It also soothes irritated scalps prone to itching.

Furthermore, the essential oil of mandarin acts as a fragrance agent in numerous formulations. It is particularly used to mask the odours of certain unpleasant active ingredients, or simply, to provide a touch of freshness to the formulas.

Although beneficial in many respects, mandarin essence has some contraindications. It notably contains allergenic molecules (limonene and, to a lesser extent, linalool) that can cause irritations and itching. Furthermore, it is contraindicated for children under six years of age. Topical use in a diluted form is possible for pregnant women over 4 months, upon medical advice. Being photosensitising, its use in the sun and/or before exposure should be avoided.

Note : It is advisable to test the essential oil before using it (two drops in the crook of the elbow for at least 24 hours to ensure that there is no reaction).

This plant extract is present in two treatments from the Racines range: the nutrition shampoo with a biolipid complex and camellia oil, and the hair repair mask with biomimetic ceramides and avocado oil. These two treatments repair and deeply nourish the hair fibre, smoothing and filling the hair's cuticles.

• PALAZZOL E. & al. Current and potential use of citrus essential oils. Current Organic Chemistry (2013).