Essential oils are volatile and oil-like mixtures obtained from plants by water or water vapor distillation, which are liquid at room temperature, with strong odor. These essential oils in plants are called essential oils or ethereal oils, since they can evaporate even at room temperature if exposed. It is also known as essential oil because of its fragrance. With these properties, essential oils are used in perfumery.

Plants containing essential oil are grown in hot regions. Therefore, the Mediterranean region in our country is the richest region in terms of plants with essential oil.

Essential oils are obtained from the essential oil bearing parts of plants, usually by distillation. The method applied is closely related to the characteristics of the plant. In general, the following methods are used: water distillation method, water and steam distillation method and direct steam distillation method. The water distillation method is preferred for plants which are more dried and do not deteriorate when boiled. The method of water and steam distillation is preferred if dry or fresh plants deteriorate when heated. Direct steam distillation is a method used only for fresh plants.

The amount of essential oil is generally 1-2 in plants. In the food industry, essential oils are used as flavorings in food products. Essential oils in spices give food taste and odor as well as have a protective effect on foods.

In the scope of chemical food analysis, the amount of essential oil in spices is determined by authorized laboratories. During these studies, the standards published by local and foreign organizations are complied with. The standard is based on:

• TS EN ISO 6571 Spices, condiments and medicinal plants - Determination of essential oil content (hydrodistillation method)