2 Learning outcomesEssential oils are the concentrated extracts of volatile, non-water-soluble aroma compounds from plants.Essential oils are widely used in perfumes, cosmetic products, cleaning products and as flavourings in foods.
3 Learning outcomes Essential oils are mixtures of organic compounds. Terpenes are the key components in most essential oils.
4 The history of essential oils The benefits of essential oils have been recognised for thousands of years.Their use is described in the New Testament of the Bible.They were used in anointing rituals and in healing the sick.
5 The history of essential oils The ancient Egyptians used essential oils for embalming, religious rites and medicinal purposes.King Tut’s tomb was found to contain 50 jars of essential oil when it was opened in 1922.
6 Modern uses Cosmetics Cleaning Flavours Dentistry Essential oils AdhesivesPerfumesInsectrepellentsMedical
7 What are essential oils? ‘Essential’ refers to the fact that the oil carries the distinctive essence (scent) of the plant.Concentrated, volatile, non-water soluble aroma compounds extracted from plants.Contain no artificial substances, unlike perfumes and fragrance oils.
8 Essential oils – composition Essential oils are mixtures of organic compounds.Terpenes are the key components of all essential oils.
9 Essential oils – chemistry The distinctive character of an essential oil can be attributed to the functional group present in its key molecule.Esters, aldehydes, ketones and alcohols are all found in essential oils.
10 Essential oils – perfume The ester linalyl acetate is found in the essential oil lavender.This ester is often added to perfumes.
11 Essential oils – cleaning The essential oil known as lemon oil contains the terpene d-limonene.It is known for its ability to act as a natural solvent and a cleanser.
12 Hospital cleanersCertain essential oils kill bacteria and fungi (including MRSA and E. coli) within 2 minutes of contact.Essential oils are blended into soaps and shampoos used in hospitals to eradicate deadly ‘super bugs’.
13 Essential oils – cosmetics The essential oil geraniol is added to some cosmetics to balance and revitalise the skin.
14 Essential oil – cold sores Melissa oil contains the terpene citral, which is used to combat cold sores.
15 Essential oils – toothpaste The essential oil thymol has antiseptic properties.
16 Steam distillationSteam distillation is one of the methods used to extract essential oils from plants.Steam passes over the plant and extracts the essential oil.The mixture evaporates and passes into the condenser.The essential oil vapour is chilled and collected.
18 Essential oils – summary Concentrated extracts of volatile, non-water-soluble aroma compounds from plants.Widely used in perfumes, cosmetics, cleaning products and flavourings.Mixtures of organic compounds.Terpenes are the key components of most essential oils.