How Is Tea Tree Essential Oil Produced?

The tea tree, also called melaleuca with alternate leaves, is a shrub native to New Caledonia and Madagascar. The main producing country today is Australia.

The leaves of tea-tree were known in Europe thanks to the English navigator James COOK who found some in the islands of the New Zealand archipelago during his journey. The aborigines used them to make a refreshing drink that they called tea. This is how, as real tea was missing, James COOK's crew ended up appreciating tea-tree leaf-based infusions.

Moreover, they also observed that the natives used this plant, and more particularly the leaves, to make poultices and treat infections. Nevertheless, it was only in 1922 that the antiseptic and antibacterial properties of the plant were demonstrated by the chemist Arthur DE RAMAN PENFOLD. At the beginning of the Second World War, the essential oil of tea tree was added to each medicine kit in the army and the Australian navy because of its anti-infectious virtues.

The tea tree and the tea plant are often confused: the tea plant belongs to the Theaceae family and comes from Asia, while the tea tree belongs to the Myrtaceae family and is native to Australia.

Tea tree essential oil is the result of a steam distillation (hydrodistillation). The set-up consists of a distillation flask/tank, a condenser and a thermometer.

1. The sample for extraction is prepared by cutting the leaves and young twigs into small pieces.

2. The plant material is then added to a flask and immersed in several liters of distilled water.

3. Then, the installation is closed so that it is airtight and the process starts at a temperature of 250°C. The procedure then lasts 4 to 5 hours.

4. The oil is collected in a separating funnel and stored in a cool, dry place.

The percentage of oil extracted is calculated by the following formula:

Essential oil yield % = Volume of oil extracted/Fresh weight of plant material (g) × 100.

Applying this formula, the yield is as follows: 100 kg of tea tree leaves are required to harvest 1 to 2 liters of tea tree essential oil. Organoleptically, it is a clear colorless to pale yellow liquid with a woody smell. It contains mainly monoterpenols (about 45% of terpinen-4-ol) and monoterpenes (gamma-terpinene, alpha terpinene, limonene). These compounds are at the origin of its purifying and cleansing properties.