**2. Methods of essential oils extraction**

Several methods of EOs extraction have been previously described. This diversity is due to the plant material variety and the sensitivity of their constituents. The choice of mode depends on the nature and the plant material parts, the physicochemical characteristics of EOs, as well as the extract uses. In this chapter, we will present some techniques for the EOs extraction.

#### **2.1 Distillation by steam entrainment**

At the Sylvo-Pastoral Resources laboratory in Tabraka, the technique consists of distilling 10 to 15 kg of plant material in the alembic with 10 L of water separated by a grid in a still (**Figure 1**). The distillation temperature is 100°C. The operation leads to the release of water vapor, which plays a dual role: (i) release of the plant essence

*Phytochemistry, Medicinal Uses, and Beneficial Nutritional Effects of Essential Oils DOI: http://dx.doi.org/10.5772/intechopen.112696*

**Figure 1.**

*Extraction of essential oils from Pinus halepensis needles by steam distillation. A: Water filling up to separation grid level; B: Introduction of plant material in the alembic. C: Complete assembly.*

and (ii) transport of the oil, which condenses during cooling. The obtained liquid contains a fraction of essential oil and another of floral water. These two constituents are separated by the difference in density.
