The fresh scents of a garden in summer or the tropical fragrant of an equatorial rain forest are caused by minute droplets of oily liquid produced by plants. These essential oils, together with synthetically produced scents, form the basis of the perfume industry.
Why plants produce essential oils is uncertain. Some may attract insects, and therefore increase the chance of pollination: others may be designed to ward off parasites or marauding animals. Of the many thousands of plants in the world, only about 200 produce the range of essential oils from which perfumeries create their fragrances.
Some perfumes contain as many 100 different oils, others have only a few. But they all share three elements: a ‘top note’, consisting of the move volatile ingredients which create the immediate effect; a ‘middle note’, which modifies the initial impression and is intended to give the perfume body; and a ‘base note’, which persists longest and leaves a lingering impression.
The ancient Greeks and Romans produced fragrant ointments by immersing flowers, leaves and roots in fatty oils, usually animal fat or olive oil, which drew out their scents. Both men and women wore these ointments, but even then they were expensive and only the rich could afford them. When Cleopatra went to greet Mark Antony she drenched the purple sails of her barge with perfume, seeking to impress him.
St Luke tells the story of a woman, identified by some scholars as Mary Magdalene, who poured ointment onto the feet of Jesus in the house of a Pharisee. The ointment would almost certainly have contained spikenard, aromatic oil obtained from the Indian valerian tree.
It was the Arabs who first used the technique of distillation to extract essential oils, and a similar process is still used today. Flowers or leaves of the scented plant are chopped or crushed, then heated with steam to force the volatile oils to vaporize. The vapour passes through a chilled glass tube which causes the oils to condense. The amount produced from most plants is very low, usually less than one-thousandth of the total material collected. But its fragrance is so intense that even diluted a hundredfold it is still overpowering.
Distillation cannot always be used because there are some fragrances that spoil if they are heated. In Grasse, the perfume centre of Provence in southern France, a technique known as enfleurage is still used for these delicate oils. Flowers are laid out in frames on layers of highly purified tallow and lard. Left in a cool dark room for between one and three days, the fat absorbs the oil from the flowers, producing a material called pomade. The unwanted fat is removed by adding alcohol, leaving just the oils in the alcohol solution, ready to be blended.
Perfume oils are often produced in remote areas by family businesses whose methods have not changed for hundreds of years. Bulgaria still produces 70 per cent of the world’s rose oil. In the valleys under the Balkan Mountains the rose-pickers gather when it is still dark. The petals have to be picked before dawn to ensure that they keep their fragrance. It takes more than 2000 petals to make every grain of the precious oil.
In many places oils are often produced at the rate of only a few tons a year. The oils are bought by brokers who sell them to exporters, and finally to the perfumeries, who compose their own fragrances, a technique which is a difficult and delicate art.
Some perfumes are floral in character, dominated by scents such as rose or gardenia. Others are oriental, herbal or spicy, containing oils of cinnamon from China, Burma and Sri Lanka, or nutmeg from Indonesia or the West Indies. Men’s aftershave often contains spicy, woody or leathery accents.
To increase the lasting power of the perfumes, fixatives are used. Formerly these came from exotic animal products – ambergris, from the intestines of the sperm whale; musk, from a gland of the male musk deer; civet, a secretion of the civet cat; and castoreum (or castor) from the gland of a beaver. However, fixatives are now chemically synthesized.
Once a fragrance has been composed from as little as 20-30 oils or as many as 300, it is sold in a variety of forms. Toilet water or cologne generally contains from 2 to 6 per cent perfume, dissolved in alcohol. Perfumes are much stronger, containing 10 to 25 per cent, again in alcohol solution.
Not all perfumes are made in traditional ways. Chemists, having analyzed the substances that produce the scents, can re-create them synthetically. The results are used in millions of applications where conventional perfumes would be too expensive – for things like polishes, air fresheners, disinfectants and shampoos.
Picture Credit : Google
