Utilization of Aromatic Plants and Derived Products

Chapter 8 

Utilization of Aromatic Plants and Derived Products

INTRODUCTION

• Aromatic plants are plants that possess aromatic compounds, most of which are essential oils which are volatile in room temperature. These compounds are synthesized and stored in a special structure called gland, which is located in different parts of plant such as leaves, flowers, fruits, seeds, barks and roots. These essential oils can be extracted by various physical and chemical processes, such as steam distillation, maceration, expression, enfleurage and solvent extraction. They are mainly used as flavours and fragrances. However, from ancient times, these plants have been used as raw materials for cosmetics, pharmaceuticals, botanical pesticides, etc.

Importance of Aromatic Plants

Aromatic Plants can be divided into four groups based on how they are utilized, viz.

• As raw materials for essential oils extraction: This is the major use of aromatic plants and is the one dealt with in this paromatic plantser. 

• As spices: These are plants in which their nonleafy parts are used as a flavouring or seasoning. 

• As herbs: These are plants in which their leafy or soft flowering parts are used as a flavouring or seasoning. 

• Miscellaneous group: These are aromatic plants used in some ways other than the ones mentioned above, e.g., as medicines, cosmetics, dyes, air fresheners, disinfectants, botanical pesticides, herbal drinks/teas, pot pourri, insect repellents, etc. 

• People have made extensive use of aromatic plants from time immemorial. The Egyptian, the Persian and the Babylonian were known to grow and use aromatic plants in making perfumes and other scented waters from a distillation of rose petals and orange blossoms. Oriental people were also fond of aromatic plants. These aromatic  plants were grown in the palace compounds and used asraw materials to make perfumes, scented water and a dozen of other aromatic products.

 IMPACT OF INDUSTRIALIZATION

• The techniques of essential oils extraction from aromatic plants have been known for thousands of year. These essential oils have been used in home-made perfumes, scented water, traditional medicine, etc. These plants were normally grown in the backyard and collected for use whenever there was a need. With the advance of industrialization through large-scale production and modern facilities for processing and utilization, aromatic plants and their products have become very popular. However, as production costs become more and more expensive, it is necessary to come up with practical solution, i.e. the invention of synthetic compounds that are almost the same as natural materials. This has considerably reduced the use of natural flavour and fragrant materials.

Volatile Oil 

• A substance of oily consistency and feel, derived from a plant and containing the principle to which the odour and taste of the plant are due (essential oils), in contrast to a fatty oil, a volatile oil evaporates when exposed to the air and thus is capable of distillation It may also be obtained by expression or extraction as many volatile oils identical to or closely resembling the natural oils can be made synthetically. This is also known as ethereal oil.

• The essential oils industry was traditionally a cottage industry in India. Since 1974, a number of industrial companies have been established for large-scale production of essential oils, oleo resins and perfume. The essential oils from plants being produced in India include ajwain oil, cedar wood oil, celery oil, citronella oil, davana oil, eucalyptus oil, geranium oil, lavender oil, lemon grass oil, mentha oil, palmarosa oil, patchaouli rose oil, sandal wood oil, turpentine oil and vetiver oil. The manufacture of turpentine oiland resin from pine is a sizable and well-established industry in India having 10,000–25,000 tones annual production of the oil—α-pinine and δ-3-carene being two vital components produced from the oil. α-Ionone from lemongrass oil for perfumery and β-ionone for vitamin A synthesis are produced in India. Before 1960, menthol was not produced in India but the introduction of Japanese mint, Mentha arvensis and subsequent improvements therefore enabled India to produce over 500 tones of menthol, and now tops the world market in export of natural menthol. Although the production of major oils is highly organized as a number of developing countries have volatile oil rich flora not fully utilized or cultivated.

Essential Oils

• The chemical components of essential oils can be divided into two main categories: the hydrocarbon monoterpenes, diterpenes and sesquiterpenes, as well as some oxides, phenolics and sulphur- and nitrogen-containing material. Common terpenes include limonene, which occurs in most citrus oils and the antiseptic pine, found in pine and terpene oils. Important sesquterpenes include chamazulenes and farnesene, which occur in chamomile oil and which have been widely studied for anti-inflammatory and bactericidal properties.

• The extensive occurrence of ester in essential oils includes linalyl acetate, which is a component of bergamot and lavender, and geranyl acetate that is found in sweet marjoram. Other common esters are the bornyl, eugenyl and lavendulyl acetate. The characteristic fruity aromas of esters are claimed to have sedative and fungicidal properties. 

• Aldehydes are also clamed to have sedative properties, the most common being citralnellal and neral found in lemon scanted oils; citral also has antiseptic properties. Equally pungent to the aldehydes in many instances are the ketones, such as jasmone and funchone found in jasmine and fennel oil, respectively. Ketones, such as camphor, carnone, methone and pine comphone, found in many proprietary preparations are effective in upper respiratory tract complaints. However, some ketones are also among the more toxic components of essential oils, and are found in pennyroyal and buchu.

• The alcohol within essential oils is generally nontoxic. Commonly occurring terpene alcohols include citronellal found in rose, lemon and eucalyptus, also geramnial, bornenol, fornenesol, menthol, nerol and linalool occurring in rose wood and lavender. Alcohol has antiseptic and antiviral properties, and in aromatherapy, they are claimed to have an uplifting quality 

• A wide range of oxides occur in essential oils including ascaridol, bisabolol and bisaleolone oxides and linalool oxide from hyssop. The most important oxide, however, is cineole. Also known as eucalyptus oil, it occurs extensively in other oils such as bey laurel, rosemary and cajuput. It is used medicinally for its expectorant properties. Utilization of essential oils in different industries has been summarized.

Utilization of essential oils

Indian scenario

•  India is one of the few countries in the world having varied agro climatic zones suitable for the cultivation of a host of essential oils bearing plants. Due to increased awareness of health hazards associated with synthetic chemicals coupled with the increase coast of petroleum products, the use of essential oils has been gradually increasing. The consumers are showing increasing preference for natural material over the synthetic. During the last few years with the spurt in the production of essential oils, it is emerging as a potential agro-based industry in India. At present in India about 30% of the fine chemical used annually in perfumes and flavours come from essential oils. The total consumption of perfumery and flavourings material in India is abut 3,800 MT/annum valued at Rs. 100 crore. Food, dental, pharmaceutical flavours share is around 700 MT, and the rest represents perfumery. The estimated production of perfumery raw material is around 500 tones/annum valued at Rs. 400 crore. According to Trade Development Authority of India, the total production of fragrance excluding formulation for captive consumption by the user industry is about Rs. 120 crore/annum. A number of essential oils form palmarosa, citronella, ginger grass, basil, mint, lemon grass, eucalyptus, cedar wood, lavender oil, davana oil, celery seed oil, fennel and other oils have been widely used in a variety of products in India. Out of these the essential oils currently being produced in India are oil of citronella, lemongrass, basil, mint, sandalwood, palmarosa, eucalyptus, cedar wood, vetiver and geranium. Rose oil, lavender, davana oil, oil of khus and ginger grass are produced in small quantities. During last forty year, the importance of developing essential oils bearing plants is being increasingly realized. With the introduction of Japanese mint and subsequent improvement there upon, India produces 5,000 tones of menthol valued at Rs. 100 crore and is oneof the leading menthol-producing country. Presently, the areas under mint cultivation are estimated to be around 40,000 hectares, mainly in U.P., Punjab, Haryana and to some extent in Bihar and M.P. The export of essential oils during the year 1991–92 has been Rs. 53.6 crore as against Rs. 40 crore during the year 1990–91, thereby registering an increases of 37% over the last year. An amount of Rs. 61 crore has been saved in foreign exchange annually by means of production of certain oils of mint, aromatic grass, linalool, geranium, lavender and rose oil during 1991–92. With the increase in production of above essential oils, it would be possible for the country to save more valuable foreign exchange in the coming years.

• The magic items of export are ginger oil, sandal wood oil, lemon grass oil, jasmine oil and other essential oils. During the year 1991–92, export of sandalwood oil has registered a recorded figure of Rs. 13 crore compared to Rs. 6.2 crore during 1990–91. The major buyers of Indian essential oils being Russia, United States, France, UK, Netherlands, UAE, Saudi Arabia, Spain, Morocco, Germany, Australia, Pakistan, Korea, and Taiwan, etc. Similarly, citronella oil production has reached 500 tons when it was totally imported 55 years ago. Also jasmine and tuberose concentrate from south India have created a marks in world marked. Thus, an interesting scenario in the development of natural essential oils in India has enraged.

World scenario

• India ranks 26th in import and 14th in respect of export in world in the trade of essential oils. United States, France and Germany are the top three countries in the world in the trade of essential oils. India holds around 7% of import and 1.1% of export. The values of export from India during 1991–92 to three major countries like United States, France and Germany have been to the tune of Rs. 21.2 crore with major share going to United States (Rs. 8.2 crore) and France (Rs. 7.39 crore).

• The world trade in essential oils and its product is vast, and the oils of major importance are aniseed, citronella, clove, geranium, lemon grass, peppermint oil, patchouli, sandalwood, vetiver, mint oil, lemongrass and palmorosa,

Future demand

• Approximately 90% of the present requirement of essential oils in the country is met by the indigenous production and 10% from import. In 1950, the production was hardly 7,580 tones, which has since been rising to 8,000 tones. This has been both vertical and horizontal growth in the production of essential oils. Peppermint, spearmint and other mint oil constitute 68% of total volume of production of essential oils in the country. Other important varieties which constitute 28% of the total production are basil oil, citronella oil, eucalypts oil, lemongrass, palmorosa, and sandalwood and vitever oil. The annual growth rate of pharmaceutical industry in terms of volume and value is expected to be between 11% and 13% in the next five years. The other important sector showing rapid expansion is the processed food industry particularly ice cream and confectionery items. Fragrance finds use in toiletries and personal care products. Volume wise toiletries constitute 90% of all these products. The annual production of toiletries has been estimated by Toilet Makers Association from 3.5 lakh tones in 1991 to 4.8 lakh tones in 1995, at an annual growth rate of 8%. The requirement of essential oils by consumer industries under fragrances, flavour and aroma chemicals are 60%, 20% and 20%, respectively.

• The association of essential oils manufactures estimated growth in export value from Rs. 50 corer in 1991–92 to Rs. 125 corer in 1995–96. India ranks 14th in the world export trade, and its share being at an average 0.6–0.8% of the total. These are an ample room for penetration into the foreign market especially to the newly developing countries of the middle and for east. 

Export of major essential oils from India

• Mentha arvensis and mint oil, cedar wood oil, clove oil, eucalyptus oil, tuberose concentrate, palmarosa oil, patchouli oil, sandalwood oil, lemongrass oil, davana oil, coriander oil, dill oil, spearmint oil, rose oil, Mentha piperita, jasmine concentrate, Jasmine oil. 

TOXOCITY OF ESSENTIAL OILS 

• With the latest therapeutic trend towards aromatherapy and excessive use of essential oils under the labels of natural products, the knowledge of toxicity of essential oils has become important to avoid their abusive use.

• As a general rule, the acute toxicity of essential oils by the oral route is low or very low; e.g. many of the oils used have an LD50 between 2 and 5g/kg body weight (e.g. anise, eucalyptus and clove) and for most of them greater than 5 g/kg body weight (e.g. chamomile, citronella, lavender, marjoram and vetiver). Other oils have further low LD50 between 1 and 2 g/kg for sweet basil, taragon, hyssop (1.5 g/kg), savoury (1.37 g/kg), sassafras (1.9 g/kg), winter green (0.9–3.25 g/kg), chenopodium (0.25 g/kg), thuja (0.83 g/kg), pennyroyl (0.4 g/kg) and mustard oil (0.34 g/kg).

• A review of the available literature shows that serious accident involves the young children, due to the ingestion of oils such as clove (eugenol) eucalyptus, pennyroyl (pulegone), winter green (methyl salicylate deadly) and parsley (apiole) in large quantity.

• The chronic toxicity of essential oils is also not well known at least for uses, such as aromatherapy as well as for any other route of administration as the doses in which they are used are too low for chronic toxicity.

• At present in India about 30% of the fine chemicals used annually in perfumes and flavour are obtained from essential oils. The total consumption of perfumery andflavouring materials in India is about 4,800 metric tonne/ annum. The food technology, oral hygiene and pharmaceutical flavour share around 900 metric tonnes and rest represents perfumery.

UTILIZATION OF AROMATIC PLANTS

Mentha Oil

• The oil is obtained by stream distillation of the fresh flowering tops of the plants known as Mentha piperita Linn; Mentha arvensis var-piperascens (Japanese Mint (Family: Labiatae). Mentha oil is commercially cultivated in U.P., Himachal Pradesh, Punjab, Haryana, Jammu and Kashmir and Central India. It contains about 80% of l-menthol. It is also cultivated in Japan, Brazil and California.

• They are colourless or pale-yellow liquid; strong and penetrating odour and taste is pungent and sensation of a cool feeling when air is drawn into the mouth.

• Mentha oil contains chiefly l-menthol to the extent of 70% in free, as well as, in the form of esters, depending upon variety (like American, Japanese, Indian). American mentha oil contains 80% menthol while Japanese oil contains 70–90%. Other important constituents of the peppermint oil are menthone, menthofuran, Jasmone, menthyl isovalerate, menthyl acetate and several other terpenes derivatives. The other terpene includes 1-limonene, isopulegone, cineole, pinene, camphene, etc., Jasmone and esters are responsible for pleasant flavour, while menthofuran causes resinilication and develops dirty smell.

Utilization of mentha oil and derived products

• Carminative. 

•  Spasmolytic. 

•  Mild antidiarrhoetic.

•  Aromatic stimulant. 

•  Cholagogue. 

•  In tooth paste preparations as a taste corrector. 

•  The oil is used for flavouring in pharmaceuticals, dental preparation, mouth washes, cough drops, soaps, chewing gum. 

•  It is widely used in flatulence, nausea and gastralgia. 

•  The oil has mild antiseptic and local anesthetic properties. 

•  It is used externally in rheumatism, neuralgia, congestive, headache and toothache. 

•  The menthol is antipruritic and used on the skin or mucous membrane as counter-irritant, antiseptic and stimulant. Internally, it has a depressant effect on the heart. 

•  The menthol is used in food industries such as liquor, soda, syrup, confectionary (candy, chewing gum and chocolate).

•  The menthol is used in cosmetic preparation like shaving cream, tooth paste, lotion, deodorant and aftershave lotion, etc.

Eucalyptus Oil

• It is a volatile oil obtained by steam distillation from fresh leave Eucalyptus globules and other species of eucalyptus (Family: Myrtaceae). It should contain not less than 65% of cineole.

• It is indigenous to Australia and Tasmania. It is cultivated in the United States (California), Spain, Portugal and in India. E. citriodora, known as citron scented or lemon scented gum, is grown on large scale basis in Kerala, Tamil Nadu and other states.

• The odour of oil is aromatic and camphoraceous. It is colourless or pale yellow liquid, having pungent and camphorous taste followed by the sensation of cold. It is soluble in 90% alcohol, fixed oils, fats and in paraffin.Eucalyptus oil chiefly contains cineole, also known as eucalyptol. It also contains pinene, camphene and traces of phellandrene, citronellal, gallo-tannins, methyl ester of p-coumaric acid, and cinnamic acid in combined form. Citriodorol (from E. citriodora). It also contains small quantity of butyric, valerenic and caproic aldehyde.

Utilization of eucalyptus oil

•  Eucalyptus oil is used as a counter-irritant, an antiseptic and expectorant. 

•  Antibacterial and antituberculosis (citriodorol). 

•  Diaphoretic. 

•  It is used to relieve cough and in chronic bronchitis in the form of inhalation. 

•  Solution of eucalyptus oil is used as nasal drops. 

•  It is used in infections of the upper respiratory tract, malaria, and certain skin diseases, in ointment for burns and as mosquito repellent. 

•  If mixed with an equal amount of olive oil, it is useful as a rubefacient for rheumatism.

Geranium Oil

Geranium oil is obtained by steam distillation of the tender parts of the plants of various species like Pelargonium (Geraniaceae) (P. graveolens, P. capitatum and P. odoratissium Linn). It is indigenous to South Africa and cultivated in Algeria, Morocco, Spain, France and Italy. Indian geranium oils obtained from other species and is known palmarosa oil.

All varieties of geranium generally contain 0.08–0.4% of fragrant volatile oil. Geranium oil contains two types of constituents, i.e. alcohol and esters. The alcohols are β-citranellol and geraniol about 60–70% of the oil. While esters namely geranyl geranyl-tiglate, citranellyl formate and citranellyl acetate contribute about 20–30% oil. Several sesquiterpenes alcohols are also reported in the oil, and are responsible for pleasant fragrance.

Utilization of geranium oil

• As a flavouring agent for creams, lotions, soap, perfumes and other products. It is also used in alcoholic, nonalcoholic beverages, candy and other dairy products at 0.001%. 

• The oil is used in the treatment of inflammation, with its mild soothing effect. 

• It is a stimulant of the adrenal cortex and can be used to balance the production of androgens which occurs during the menopause. 

• The oil is good insecticide.

Vetiver Oil (Khus Oil)

• It is obtained by steam distillation from roots of the plant of Vetiveria zizanioides Stapf (Family Graminae).

• The plant is found growing in India, Myanmar, Sri Lanka and East and West Africa. It is cultivated in Indonesia, Caribbean Islands, Malaysia, and the United States. In India, it is found abundant in Punjab, Rajasthan, Kerala, Karnataka and Tamil Nadu.

• Cultivation of vetiver grass is done by sowing the seeds or from slips. A well-drained sandy loam is most suitable for cultivation. The temperature ranging from 25–38°C and rainfall of 100–200 cm are desired. It thrives best in marshy places and humid climate. Planting of slips is done just before the outbreak of monsoon. The distance between two plants and between two rows is approximately 2.5 cm. Proper arrangements for irrigation must be made after rainy season is over. Fertilizers and manures are provided to produce sturdy grass and roots. The grass attains the height of 1–1.5 meters above the guard. When the plant is about 15–18 months of age, the roots are collected by uprooting in dry months of the year. If necessary, digging is done for collection of roots. The drug is slashed, cut into small pieces and used for extraction of oil.

• Colour of oil is light brown to deep brown or green and odour is characteristics. It is soluble in fixed oil and alcohol.

• The vetiver oil mainly contains alcohol (45–60%), i.e. vetivenol, vetiverol, and 8–35% ketone namely 3-vetivones. Indian vetiver oil contains khusal, khusitol and khusinol.

Utilization of vetiver oil

• It is used as stimulant, refrigerant, flavouring agent. aromatic, stomachic and in the treatment of prickly heat or itches. 

• It is used as antiseptic, antispasmodic and rubefacient. 

• It is also used in burns, sores and as diaphoretic. 

• It is also used in preparation of sherbet, soap, perfumery and toilet preparations and as a fixative of volatile oils.

Sandalwood Oil

• Sandal wood oil is obtained by distillation of dried heart wood from the plant Santalum album Linn (Family: Santalaceae)

• The sandal tree is available in India and Malaya. In India, the trees are available in Tamilnadu, Mysore, Maharastra, Uttar Pradesh, and Madhya Pradesh, Assam, Bihar, Rajasthan and Gujarat

• Sandal wood oil is yellowish and pale reddish viscous liquid. It has strong fragrance, taste is slightly bitter.

• Sandal wood oil contains mixture of two isomers α- and β-santolol (90%), α and β-santalene, santalone, santanone, isovaleraldehvde, α- and β-santalic acids, etc.

Utilization of sandalwood oil

• Oil is used as perfuming agent in various cosmetic preparations and incense sticks. 

• It is used for wound and blisters caused by small pox vaccination, gonorrhoea, cough and dysuria. 

• Sandal wood oil along with neem oil is used as a contraceptive. 

• Sandal wood oil along with double quantity of mustard oil used for treatment for pimples on the nose. 

• Sandal wood oil and sandalwood are considered as cooling, diuretic, diaphoretics and expectorant drugs. 

• It is very gentle antiseptic and diuretic and is useful in urinary problem like cystitis.

Utilization of sandalwood

• Sandal wood is used for preparing several articles such as small boxes, cabinet panels, combs, book mark, walking stick, pen-holder, card cases, paper cutter, picture frames, etc. 

• Sawdust from heartwood is mostly used as incense for scenting cloths and cupboards, and for stuff in pincushions. 

• Fine powder of sandal wood is used as a cosmetic.

Lemon Grass Oil

• Lemon grass oil is the oil distilled from Cymbopogan flexuosus Stapf or from C. citrates Staf (Family: Graminae).

• Lemon grass oil is a reddish yellow or brown. It has odour resembling that of lemon oil. It is almost entirely soluble in 70% alcohol; the solubility gradually decreases on storage.

• Lemon grass oil mainly contains citral and citranellal (75–85%). The other terpene is geraniol, nerol, linalool,methyl heptenol, limonene, etc., β-ionone is derived from citral.

Utilization of lemon grass oil

•  It is used as flavouring and perfuming agent. 

•  It is also used as a mosquito repellent. 

•  It is used as a source of citral for the preparation of β-ionone. 

•  The β-ionone is used as precursor of vitamin A. 

•  The oil is used in perfumery, soaps, and cosmetics.