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Essential oils, or volatile oils, are found in many different plants. These oils are different from fatty oils because they evaporate or volatilize on contact with the air and they possess a pleasant taste and strong aromatic odor. They are readily removed from plant tissues without any change in composition. Essential oils are very complex in their chemical nature. The two main groups are the hydrocarbon terpenes and the oxygenated and sulphured oils.
These oils do not have any obvious physiological significance for the plant. They may represent byproducts or metabolism rather than foods. The characteristic flavor and aroma that they impart are probably to some advantage in attracting insects and other animals, which play a role in pollination or in the dispersal of the fruits and seeds. When in high concentration, these same odors may serve to repel enemies of the plants. The oils may also have some antiseptic and bactericidal value. There is some evidence that they play an even more vital role as hydrogen donors in oxidoreduction reactions, as potential sources of energy, or in affecting transpiration and other physiological processes (Hill 1952).
All the distinctly aromatic plants contain essential oils. They occur in over 60 families and are especially typical of the Lauraceae, Myrtaceae, Umbelliferae, Labiatae and Compositae. The quantity of oil varies from a very small amount to as much as 1-2 percent. The oils are secreted by internal glands or in hair like structures. Sometimes, as in wintergreen and mustard, the oil is not present in the plant but develops only as the result of chemical action when the ground-up plant tissue is extracted with water. Almost any organ of a plant may be the source of the oil. Examples are flowers (rose), leaves (mint), fruits (lemon), bark (cinnamon), wood (cedar), root (ginger) or seeds (cardamom), and many resinous exudations as well.
These oils are extracted from the plant tissues in different ways depending on the quantity and stability of the compound. Three principal methods are: expression, distillation and extraction by solvents.
The history of civilization is directly connected with that of perfumes. Perfumes have been in widespread use since the earliest recorded times. The Egyptians and ancient Hebrews used them for both personal and religious purposes. They played an important role in the life of the Romans and Greeks, reaching such a high degree of specialization with the Greeks that a special perfume was required for each part of the body. Later Catherine de’ Medici knew as much about perfumes as she did about poisons. In the time of Queen Elizabeth a gift of rare perfumes was a definite way to win the royal favor, while the court of Louis XIV at Versailles had a particular perfume for each day of the year, the preparation of which was supervised by the king himself. In those days perfumes were of hygienic as well as aesthetic value for they acted as true antiseptics and deodorants and masked offensive odors at a time when bathing was infrequent. Perfumes have continued to be in great demand to the present day. The consumption of the natural products has gradually increased in spite of the many synthetic substitutes that chemists have placed on the market. Synthetics are not as long lasting as those obtained directly from the plants.
The most valuable perfumes are combinations of several essential oils. Frangipani, for example, contains sandalwood, sage, neroli, orris root, and musk, while one of the formulas for Eau de Cologne, which dates from 1709, calls for neroli, rosemary, lemon and bergamot dissolved in pure alcohol and aged. “The expert perfumer must be able to blend the several oils at his command as an orchestra leader combines the various instruments into a perfect whole” (Hill 1952).
Perfumes also contain fixatives, which are substances that are less volatile than the oils and which delay and so equalize evaporation. These may be of plant or animal origin. Musk, ambergris, and civet are frequently used for this purpose. Balsams and oleoresins, such as benzoin, styrax, and oak moss; essential oils with a low rate of evaporation like orris, patchouli, elary sage, and sandalwood; and various synthetic materials are also used.
Perfume plants are cultivated for the most part in areas bordering on the Mediterranean Sea and the Indian Ocean. Most of the natural perfumes are made in southern France in the region around Grasse and Cannes near the French Riviera. Here garden flowers are cultivated on a large scale, and from 10-12 billion pounds were being gathered annually by the mid 1950’s. These included over 5 million pounds of orange blossoms, over 4 million pounds of roses, 440 thousand pounds of jasmine and 330 thousand pounds of violets. Large quantities of tuberoses, cassie, jonquils, thyme, rosemary, lavender and geraniums are grown and many other fragrant species to a lesser degree. Flowers are also grown for the perfume industry to some extent in Reunion, North Africa, England and various European, Pacific and Asiatic areas. When supplies were reduced during World War II, the United States developed substitutes and initiated or increased the cultivation of several essential oil plants in Central America. Of the 75 essential oils regularly used in the industry only eight are normally produced in the Western Hemisphere, and only oil of petitgrain is of much importance.
Some of the more important essential oils used in the manufacture of perfumes are as follows:
<bot808> Apricot (Prunus armeniaca L.) (fruit; perfumes; medicines) [Manchuria]
This is valuable oil that is also called Attar of Roses. It has been one of the most favorite perfumes either in combination with other oils or alone. Bulgaria supplied most the commercial supply in the 20th Century. The damask rose, Rosa damascena, was the main source. By the mid 1900’s over 12,000 acres on the southern slopes of the Balkans were devoted to its cultivation. The harvest period covers about three weeks during May-June. Flowers are picked in the early morning just as they are opening and are distilled immediately. In the beginning of this industry peasant farmers utilized their own primitive stills, but this gave way to larger modern distilleries. The oil is colorless at first but gradually turns a yellowish or greenish color. More than 20,000 lbs of the flowers are required to make one pound of the essence, which was valued at $200.00 in 1952. Very little pure Otto reaches the markets because it is almost always diluted with geranium or palmarosa oil or geraniol, which also have a rose like odor. Otto of Roses is also manufactured in France, Italy, North Africa, Asia Minor and India. In France the cabbage rose, R. centifolia was used and the perfume was obtained both by hot and cold enfleurage as well as by distillation. Large quantities of rose water are also made. This consists mainly of the water left after distillation, which still contains some of the essence. Dissolving a small amount of Otto in water sometimes makes it.
Pelargonium spp. leaves yield an essential oil after distillation. Geranium oil is widely used as an adulterant of or a substitute for Otto of Roses in making perfumes and soap. Pelargonium graveolens is most frequently grown especially in Algeria and Reunion and to a lesser extent in southern France and Spain. Cultural experiments have been made in Florida, Texas and California with P. odoratissimum, the rose geranium. The plants are easy to propagate from slips and are productive for 5-6 years after reaching maturity. They must be grown in minimum frost areas. A good grade of oil is obtained from the leaves of this species.
A very valuable oil in the perfume industry, it is added to almost every perfume. The name translates as “flower of flowers.” The ylang-ylang tree is an Eastern Asiatic species, Canaya odorata. Its yellowish-green, bell shaped flowers have an exceedingly delicate and evanescent fragrance. The oil is also known as Canaga Oil and is derived by simple distillation or extraction from the petals of fully opened blossoms. Most production was originally in The Philippines, but later French colonies in the Indian Ocean dominated the cultivation. This tree grows wild or cultivated in various parts of Southern Asia and the East Indies. The oil first arrived in Europe around 1864 and since that time it has been in great demand despite its high cost.
Flowers of the sweet acacia, Acacia farnesiana, yield an essential oil that is almost as valuable as Ylang-Ylang or Otto of Roses. It is a thorny small tree of the West Indies, but has spread to many tropical and subtropical areas. It is extensively cultivated in southern France, Algeria, Egypt, Syria and India as a source of perfume. The oil is removed from the petals by maceration with cocoa butter or coconut oil, or by extraction. It is similar to the odor of violets and is widely used for sachets, powders and pomades.
This oil, obtained from orange blossoms, is extensively used in blends and for mixing with synthetic perfumes. True oil of neroli, or Neroli Bigarade, is distilled from flowers of the bitter orange, Citrus aurantium. Neroli Portugal is from the sweet orange, Citrus sinensis. Leading production has been in southern France, surrounding Mediterranean areas and in the West Indies, particularly in Haiti.
Other essential oils are also derived from Oranges and used in making perfumes. The leaves and twigs and sometimes immature fruits, supply Petitgrain Oil. This adds a pleasant bouquet to scents, cosmetics and soap. Paraguay has been the main producer. Bitter or sweet oranges are used and the oil is extracted by distillation. Oil of Orange is obtained by expressing the ripe orange peel, but it results in an inferior grade.
This is greenish oil that is expressed from the rind of the bergamot (Citrus aurantium subsp. bergamia). It has a soft sweet odor and has been widely used in the United States for adding scent to toilet soaps and in mixed perfumes. Italy and Sicily have been the chief exporters.
Rhizomes of Iris pallida, I. florentina and allied species contain an essential oil that has the odor of violets. Tincture of Orrisroot has been used to adulterate pure extract of violets and the powdered root is the basis of violet powder. Cultivation is in Southern Europe, Iran and northern India. Italian orrisroot is superior to other sources. The rhizomes are peeled and dried in the sun, and the odor gradually develops. Orris is also used as a flavoring substance.
The roots of Calamus are the sweet and aromatic rhizomes of the sweet flag, Acorus calamus. It is a common plant of marshy ground in Europe, Asia and America. In powdered form Calamus is used for sachet and toilet powders, while the distilled oil is used in making perfumes. It has also been used for medicinal and flavoring purposes. The candied root was once a popular confection.
Several important essential oils are derived from grasses and used in the perfume industry. The genus Cymbopogon (formerly Andropogon) is especially rich in perfume species.
The oil is distilled from the leaves of Cymbopogon nardus. Java and Sri-Lanka have produced most of the world supply. The pale-yellow oil is inexpensive and used for making soaps and perfumes and as an insect repellent. The oil contains 80-90 percent geraniol, and is therefore an important substitute for Otto of Roses. Citronella was also introduced into Central America where a considerable industry developed in Guatemala and Honduras with over 4,500 acres under cultivation by 1952. The crop is harvested by hand. Cutting stimulates growth and a new crop is available in three months. The oil is extracted by steam distillation.
Leaves of Cymbopogon citratus yield reddish-yellow oil with a strong odor and taste of lemons upon distillation. There is a very high content of citral in the leaves (70-80%). It is used in soaps and medicine. Citral is extensively used in perfumes, bath salts, cosmetics and toilet soaps and as a food flavoring. It is also the source of the aromatic substances known as ionones, which have many uses. One of the ionones is required in the synthesis of Vitamin A; another is the raw material for synthetic violet.
Lemon grass is common in the eastern tropics and is cultivated in Sri-Lanka, East Africa, India, the Congo and Madagascar. It was successfully introduced in the Western Hemisphere where large quantities of the oil were exported from Haiti, Brazil, Guatemala, El Salvador and other Neotropical areas.
These are nearly identical oils that have been used as adulterants of Otto of Roses. They contain a high amount of Geraniol. Cymbopogon martinii and related species are cultivated in India as a source and have been exported in large quantities.
The roots and rhizomes of the khuskhus plant, Vetiveria zizanioides, supply this oil. It is a native of Bengal and India, but has been grown throughout the tropics and subtropics. The roots have a very sweet scent and are made into mats, fans, screens, awnings, sunshades, baskets, sachet bags and pillows. The leaves are odorless. The plant was introduced into the West Indies and Louisiana and is widely used as an ornamental plant. It has escaped cultivation and become naturalized in many areas. On distillation the roots yield oil that is similar to citronella and which has been used for making expensive perfumes, soaps and in medicine. It is one of the best fixatives.
Leaves of Pimenta racemosa yield oil on distillation, which is used in perfumery and in the preparation of bay rum. The plant is native to the West Indies where the industry is located. Originally the leaves were distilled in rum and water, but now the oil is dissolved in alcohol and various aromatic substances are mixed in. Bay rum has soothing and antiseptic properties.
Lavender perfumes are very old and were used by the Romans in their baths. It is still one of the most important scents. The true lavender plant, Lavandula officinalis, is native to Southern Europe, where it occurs on dry, barren soil. It is a low shrub with terminal spikes of very fragrant bluish flowers. There are many horticultural forms and hybrids occur. Lavender is grown in southern France at altitudes of 1500-1800 ft. Large amounts are also raised in England. Lavender has a clean odor and the dried flowers are used in sachets and for scenting chests and drawers. The oil is important in the manufacture of Eau de Cologne and other perfumes and is also used in soaps, cosmetics and medicine as a mild stimulant. Lavender water, a mixture of the oil in water and alcohol, is popular in England (Yardley brand).
<bot461> Wild Lavender (Lavandula officinalis Chaix.) [S. Europe], north coast Jamaica
This lavender, Lavandula latifolia, is coarser and yields an inferior grade of oil. It can be grown at lower altitudes than true lavender and is extensively cultivated in France and Spain. It is used in perfumes and cosmetics and to flavor meat sauces known as aspic.
One of the most popular perfumes is made from violets. Blue and pur0le double varieties of Viola odorata, native to Europe, are grown mainly in the vicinity of Nice. Solvents or maceration with hot fats extracts the oil. It occurs in such minute amounts that 15 tons of flowers are required to obtain only one pound of oil. Genuine violet perfume is rare and expensive, and it has been almost entirely replaced by synthetic products derived from ionone.
A highly esteemed perfume, jasmine is cultivated in southern France and surrounding areas. The main source is Jasminum officinarum var. grandiflorum, which is usually grafted on a less desirable variety. The flowers are picked as soon as they are open and the oil is extracted by enfleurage.
There are thousands of horticultural varieties of carnation all derived from Dianthus caryophyllus, a species of southern Europe, Northern Africa and tropical Asia. The most conspicuous blossoms and color give the least odor. Therefore, for the perfume industry varieties with less conspicuous blossoms are used. Solvents extract the oil. Synthetic carnation oil predominates in world markets.
Rosemary, Rosmarinus officinalis, is a native of the Mediterranean region. It has long been a favored sweet-scented plant and has been important in the folklore of many countries. It is one of the least expensive and most refreshing odors. The plant is a small evergreen shrub that is cultivated in Europe and the United States. The oil is extracted by distillation of the leaves and fresh flowering tops or by extraction. It is used in Eau de Cologne, toilet soap and medicine. The leaves are valuable as a spice.
Hyacinthus orientalis is native to Western Asia and Asia Minor. It was introduced into Europe in the 16th Century where it was grown as an ornamental plant especially in The Netherlands. It is also a familiar species in North America. Hyacinths are grown for perfume in southern France. The odor is heavy, sweet and quite overpowering. Solvents are used to obtain the oil, which is generally greatly diluted.
Oak Moss, also called Mousse de Chene, is a valuable addition to the raw materials of the perfume industry. It comprises various lichens that grow on the bark of trees. The main sources are European species of Ramelina and Evernia, particularly R. calicaris, E. furfuracea and E. prunastri. These lichens contain oleoresins that are extracted by means of solvents. After they have been collected, the lichens are dried. Then the perfume develops in storage. Oak moss not only has a heavy, penetrating odor and blends well, but also has a high fixative value. It is an essential element in lavender perfumes and soap and in the better grades of cosmetics.
Several sources of this very aromatic substance occur. Mexican linloe is distilled from wood chips of two species, Bursera penicillata and B. glabrifolia. Cayenne linaloe or Bois de Rose is derived from Aniba panurensis of the Guianas, while Brazilian Bois de Rose is from A. rosacodora var. amazonia, a tree in the lower Amazon basin. The product is widely used in perfumes, soaps, and cosmetics and for flavoring of foods and beverages.
The oil is obtained by distillation from the wood of Santalum album and related species. The tree grows wild in India and other parts of Southeastern Asia and is cultivated in many other areas. The oil is used throughout the Orient as a perfume and also in medicine. It is an excellent fixative and is used in blends. The sweet-scented wood is made into chests and boxes. Demand for sandalwood has been very great, resulting in the eradication of the species in many areas. Several substitutes have been used.
This oil is obtained from the flesh leaves and young buds of Pogostemon cablin. The plant is a small shrub that grows wild in Southeastern Asia and is cultivated in China. The leaves are fermented in piles and are then distilled. The dark-brown oil has a powerful odor, resembling that of sandalwood. It is one of the best fixatives for heavy perfumes. It is also used in soaps, tobacco and hair tonics. It imparts the characteristic odor to cashmere shawls, which are shipped in patchouli-scented containers.
This oil constitutes one of the most famous perfumes of India and other oriental countries. It is obtained from Michelia champaca, a large tree of the eastern tropics. The conspicuous yellow flowers are very fragrant and are frequently worn by the natives. The oil is removed from the flowers by maceration or extraction and rivals ylang-ylang in its delicious fragrance.
Misc Perfume Sources
Some of the gum resins, mainly frankincense and myrrh, have been used in perfumery for thousands of years.
Other garden flowers that are cultivated for their perfume include Heliotrope (Heliotropium arborescensj), Lily of the Valley (Convallaria majalis), Jonquil (Narcissus jonquilla), Mignonette (Reseda odorata), Narcissus (Narcissus tazetta), Clary Sage (Salvia sclarea) and Tuberrose (Polianthes tuberosa).
Oils from caraway, anise, cassia, cinnamon, clove, peppermint, lemon, thyme wintergreen and zedoary have also been used in the perfume industry, but these are discussed under other categories.
<bot787> Red Coondoo (Mimusops elengi L.) (fruit; dysentery treatment; perfumes; paint oil) [India]
<bot745> Makrut Lime (Kaffir Lime) (Citrus hystrix DC) (fruit; perfumes) [Sunda Islands]
Camphor is an important essential that is used in industry. Commercial camphor, called camphor gum, consists of tough, white translucent masses or granules with a penetrating odor and pungent aromatic taste. It is solid at room temperature, thus bearing the same relation to the other essential oils that vegetable fats do to the fatty oils. It volatilizes very slowly.
The oil is obtained by distillation of the wood of the camphor tree, Cinnamomum camphora, and native to China, Taiwan and Japan. This is a very tall and striking tree with shiny, dark evergreen leaves. The tree has been widely introduced into tropical and subtropical regions, mainly as an ornamental plant. The camphor industry is centered in Taiwan. Earlier crude methods of obtaining camphor were very destructive and the existence of the tree was threatened. Finally only trees 50 years of age or older were used and every stages in the process was carefully regulated. The wood is reduced to chips or ground to a fine powder and the leaves are also ground up. This is then distilled with steam for several hours and the crude camphor crystallizes on the walls of the still. This is removed and must be purified before it is ready for market. Synthetic camphor from pinene, a turpentine derivative, gradually dominated the market.
The principal use of camphor has been in the manufacture of celluloid and various nitrocellulose compounds. It also has a wide range of medicinal uses, both internally and externally. It is also used in perfumery.
Borneo camphor, obtained from Dryobalanops aromatica of the east Indies, has been used as a substitute.
Cedarwood oil, along with clove and bergamot oils, is one of several of the essential oils have a high refractive index and are valuable as clearing agents in the preparation of permanent microscopic mounts and for use with oill-immersion lenses. This inexpensive oil is obtained by steam distillation from the heartwood of the eastern red cedar, Juniperus virginiana, and related species. Wood chips, sawdust, waste from the lead pencil and other industries, old stumps, roots and even fence rails have been utilized. Cedarwood oil is also used in perfumery, soaps, deodorants, liniments, cleaning and polishing preparations and as an adulterant of expensive sandalwood and geranium oils. It has insecticidal properties and is used as a moth repellent and in fly sprays.
Essential oils are also useful as solvents for paints and varnishes. The most important of these is oil of turpentine. Various other oils, mainly eucalyptus oil from Eucalyptus dives, are employed in the flotation process for the separation of minerals from their ores. Still other volatile oils have been used in the preparation of cleaning materials and other industrial purposes.