Processing of Medicinal Plants

  • Plant kingdom is a rich source of therapeutic agents for the prevention and cure of various aliments of human beings and animals since the ancient times. These plants contain secondary metabolites like alkaloids, steoids, plant phenolics, saponins and volatile oils which are the potential sources of drugs.
  • In this modern age, these crude drugs and their products find an important place in our day to day life. Aromatic substances affect human behavoiur. Several of these make food, environment an human interactions more attractive.
  • Aromatic chemicals and oils are widely used in food, flavour, perfumery and cosmetic industries. Biologically active secondary metabolites and their derivatives are widely used in the treatment of variety of human aliments.
  • In the past few years, there has been a tremendous increase in the number of drugs derived from various sources mainly because of the due recognition of medicinal and aromatic plants the world over coupled with the basic realisation that drugs and essential oils derived from plants are much safer to use and are easily available at a price within the reach of a common man, with least side effects as compared to synthetics.
  • Though the usage of herbal and naturally based medicines have traditionally been used in Indian system of medicines since ancient times like Ayurveda, Sidha and Unani, the utilization of the whole plant or other crude preparation for therapeutic or experimental reasons can have several drawbacks like :
      1. Variation in the amount of the active constituents with geographic areas, from one season to another, with different plant parts and with different climatic and ecological, conditions.
      2. Concurrence of undesirable compounds which can cause synergistic, antagonistic or other undesirable and possibly unpredictable, modulations of the bio-activity.
      3. Bio-activity losses due to variability in the collection, storage and preparation of the raw material.
      4. Adulteration of the plant material.
      5. The difficulty in drug standardisation.
  • Thus, the isolation of pure natural product with bioactivity other than the crude drug has become necessary and also has several advantages, which include :
1.Administration of the pure bioactive compound in reproducible, accurate doses with obvious benefits from an experimental or therapeutic point of view.
2.Development of analytical methods for particular compound or for the group of compounds. This is more useful in the screening of plants for potential toxicity and quality control of food for human and animal consumption.
3.Structure determination of bioactive compounds. This will enable the production of synthetic material, incorporation of structural modification and rationalization of mechanism of action. This will in turn lead to reduced dependency on plants as source of bio-active compounds where by saving ecological system and will enable investigations of structure / activity relationship there by development of new compounds with similar or increased activity and less toxicity. Further this will help in saving the rare plant species before they become endangered.

  • Before 1947, the production of the plant based modern drug in India was confined to quinine from Cinchoma. The very first phytopharmaceutical industry for quinine was established by then the British Government at Mungpoo in Darjeeling. During the last five decades bulk production of plant based modern drugs has become an important segment of Indian pharmaceutical industry.
  • National Cancer Institute (USA) beginning in 1959screened more than 1,84,000 plant extracts covering 3500plant genera during a period of 20-25years, but this did not result even a single drug for the market but several very interesting leads were obtained.
  • CDRI, Lucknow investigated more than 2500 plant extracts for a wide range of pharmacological activity. Similarly, CIBAGEIGY and others also spent considerable time and money in screening medicinal plants for bioactive compounds.
  • Some of the most important plant based chemotherapeutic agents currently in use are Reserpine, an antihypertensive drug from Rauvolfa serpentina.
  • Vinblastine and Vincristine from Catharanthus roseus for the treatment of Hodgkin's disease, lymphocarcoma and leukaemia in children.
  • Teniposide and Etoposide developed from the antineoplastic agent Podophyllotoxin a constituent Podophyllum spp. Currently being used against testicular cancer, small cell lung cancer and lymphomas
  • Paclitaxal generally known as Taxol, a diterpenoid constituent Taxus spp. Is effective in the treatment of metastatic ovarian cancer and has potential use in the treatment of lung cancer, metastatic breast cancer and malignant melanoma
  • Irenotecan, an analogue of quinoline alkaloid Camptothecine first isolated from Camptotheca acuminata is being used for the treatment of lung, ovarian and cervial cancers. The herb Artemisia annual L. has been traditionally used in China or treatment of fevers.
  • CIMAP has developed a number of process technologies for the isolation of these bioactive compounds. The process technologies developed at CIMAP, Bangalore field station includes the processing of Catharanthus reseus roots for the preparation of the anithypertension alkaloid Ajmalicine and Glorisosa Superba for the preparation of Colchicine, a neoplastic agent used in the treatment of gout are discussed briefly.
  • The purity of the products can be determined by their physico-chemical constants like melting point, boiling point, optical rotation etc. as well as the study of their spectroscopic properties. The usual spectorscopy technique used are UV, IR, NMR and Mass. This layer Chromatography and HPLC are usually employed for determining their purity and quantiative estimations.
  • Bio-active compounds of current interest :
  • Taxol from Taxus baccatta and T.brevifolia
  • Podophyllotoxin and its semisynthetic derivatives from Podophyllum emodi
  • Camptothecin from Mappia foetida or Nathapdytes foetida (Wright) Soleumer
  • Artemisinin and its arteether from Artemisia annua
  • VLB and VCR from Catharanthus roseus
  • In conclusion, Indian sub-continent is a highly potential area for the phytopharmaceuticals, because of its particular advantages compared to other regions such as the availability of well documented knowledge from Vedic times as well as abundant availability of the flora of this region.


Technology For Jasmine and Tuberose concretes

  • Jasmine and tuberose concretes and their absolutes are invaluable items in perfumery.
  • They are used in highly expensive perfumes and there is considerable quantities of both Jasmine and Tuberose concretes for the last 20 years.
  • Jasmine concrete is the product obntained by solvent extraction of the fresh harvested jasmine flowers.
  • It has a semisolid consistency and contains the volatile perfumery principles of the flowers, waxes and colouring matters. Jasmine absolute is the product obtained by removing the waxes from the concrete.
  • It is reddish-brown free flowing liquid and represents the concentrated from of jasmine perfume. Although there are several methods of preparation of jasmine perfumes, solvent extraction method is generally employed.
  • The solvent used for extraction is hexane. Two varieties of the flowers of scented jasmine are preferred for the production of the concretes. They are Jasminum grandiflorum (Chameli) and Jasminum sambac (Gundumalle).
  • The yeild of concrete from the grandiflorum flowers is about 0.25 - 0.3 % and that from sambac flowers is about 0.15 - 0.18 %.
  • The absolute content in the concretes varies from 45 - 55 % depending the extraction technique and also on the place of cultivation of the plants.

Chemical composition of the Absolutes of Jasmine

  • The main constituent of grandiflorum absolute are benzyl benzoate, phytol and isophytol.
  • The monir constituents eugenol, cis-jasmone, n-acetyl methyl anthranilate jasmine lactone and cis- and trans-methyl jasmonates are responsible for the characteristic fragrance of grandiflorum absolute.
  • The main constituents of sambac absolute are benzyl alcohol, linalool, cis-3-hexenyl benzoate, indole, (E)- -farnesene and methyl anthranilate. The minor odorous principles of the grandiflorum absolute are also present in the sambac absolute.
  • The odour characteristics of the two absolutes are distinctly different because of the differences in their chemical composition.

Tuberose concrete and absolute

  • Like Jasmine concrete and absolute, tuberose concrete and absolute prepared from the flowers of tuberose (Polianthes tuberosa) are also valuable item of perfumery.
  • Tuberose flowers emit a powerful and delightful fragrance. Tuberose concrete and absolute are prepared in the same way as jasmine conrete and absolute. There are three varieties of tuberose available.
  • Only the flowers of signal petal variety are suitable for perfumery and are used for concrete production.
  • The main chemical constituents of tuberose absolute are methyl salicylate, geraniol, methyl eugenol, jasmine lactone, trans-methyl isoeugenol, benzyl benzoate and phytol.

Machinery and Equipment required

  • Stainless steel extractors, SS condensers, solvent rectification assembly, SS storage tanks, chilling unit, vaccum pump and boiler.

Economics of the Project

The approximate economics of the project were worked out as follows

Capacity of the plant
500 Kg Flowers processing
Per day
Production per season

Investment required

Cost of Production

Returns from sale of the produce


Return on Investment

Gradiflorum concrete
Sambac concrete
Tuberose concrete





16.0 x 100/ 55

94 Kg
56 Kg
12 Kg

Rs. 55.00 Lakhs

Rs. 30.00 Lakhs

Rs. 46.00 Lakhs

Rs. 16.00 Lakhs

= 20 %

  • The project is economically viable. It would be better to establish the units near the cultivation area so that the flowers can be transported easily. At present the international process for these .
  • products are Rs. 26,0001= per I Kg for grandiflorum concrete, Rs. 32,0001= per 1 Kg of Sambac concrete and Rs. 35,0001= per I Kg of Tuberose concrete.
  • The prices are subject to fluctuation and are dependent on the qual ity of the products. The season for the flowers lasts 6 months in a year


Technology for the production of value added products from essential oils

  • Essential oils are the volatile oils of aromatic plants used in perfumery, cosmetic and flavour industries.
  • They are also used in aromatherapy. They contain mixtures of organic compounds belonging to different classes of compounds such as terpenes, phenols, phenyl propanoids, aliphatic compounds etc., Monoterpenes and their oxygenated derivatives are mostly the class of compounds present in several essential oils.
  • Also some heterocyclic compounds and amino compounds are present as minor constituents of some oils and floral absolutes.
  • Oxygenated monoterpenes are the main odour carriers of the essential oils and are more stable than the terpene hydrocarbons which have a tendency to get oxidised and resinified under the influence of light, air and moisture. Improper storage conditions also cause deterioration in quality and odour of the soils.
  • Thus, if the terpene hydrocarbons are removed from the soils, terpeneless oils comprising mostly oxygenated terpenes are obtained. Terpeneless oils are more valuable than drude essential oils.
  • Many essential oils contain one, two or three major constituents of value in the perfumery. Examples include citral in lemongrass and Litsea cubeba oils, citronella in Eucalyptus citriodora and Java citronella oils.
  • These aromatic compounds can be separated from the oils and used in the perfumery.
  • Sometimes the compounds obtained from essential oils are chemically modified or converted to tother perfumery compounds / products can be prepared from essential oils. Vlue addition of the oils can be achieved by

    3.Deterpenation, and
    4.Chemical modification.


  • It is the process of redistillation of an essential oil either with steam or under vaccum. The process is useful to improve the quality of the
  • oil which has deteriorated on long prolonged storage, due to rust formation or due to emulsion formation with water.
  • After rectification, the appearance of the oil will generally be improved as non-volatile and resinified impurities are left behind in the idstillation still.


  • Fractionation of essential oils is generally done to produce perfumery compounds present as major constituents in the oils.
  • The boiling points of the constituents of the oils at atmospheric pressure are different. By making use of the differences in the boiling points, individual compounds of the oils can be separated.
  • For example, citronellal which is a major constituent of oil of Eucalyptus citriodora leaves can be separated by fractional distillation.
  • Fractional distillations are usually carried out under high vaccum which lowers the boiling points of the compounds. This prevents any damage to the compounds by heat.
  • Examples for some value added perfumery compounds / products from essential oils are given Table 1. The typical fractional distillation assembly is shown in Fig.1. It consists maily a pot in which the oil to be fractionated is placed, fractionating column, condensers, product cooler, receiver and vaccum pump.

Chemical modification

  • Value addition of essential oils can also be acheived by chemical modification of the compounds obtained from essential oils by fractional distillation. Examples of such chemical modification include conversion of the pinenes obtained from turpentine oil to a variety of oxygenated monoterpenes like linaloo, l-terpineol, etc., conversion of citral from lemongrass oil to the ionones. Deterpenation of essential oils is carried out o improve the quality of the oils.
  • If the terpene hydrocarbons which have much inferior perfumery value compared to oxygenated terpenes are removed from the oils, the concentration of oxygenated terpenes will be increased. Terpenes oils have longer shelf life and fetch more price than the crude oils.

Economics of the Project

  • Economics have been worked out for processing Java citronella oil, lemongrass oil, palmarosaoil, Eucalyptus citriodora oil.


40 Kg of Essential oil to be processed per day, 300 working days in a year

Investment required

Cost of Production

Returns from sale of the produce


Return on Investment

Rs. 16.00 lakhs

Rs. 34.80 lakhs

Rs. 40.30 lakhs

Rs. 5.50 lakhs

= 34.3 %

Essential oils and their value added products

Essential oil
Value added products

Java citronella

Eucalyptus citriodora



Menthol mint



Citronellal, citronellol. Geraniol and rhodinol



Rhodinol ex geranium


Geraniol ex palmarosa

Methyl chavicol



  • Distillation is the process by which essential oils are extracted from aromatic crops. This can be done in two ways

Steam Distillation

  • In this Process, steam generated in a boiler is passed through steam pipes into distillation tank which is filled with harvested aromatic crop.
  • Pressure, temperature and amount of, the steam can be regulated as per requirement, thereby time of distillation can also be varied.
  • The steam converts the essential oil in the aromatic plants into oil vapour and both these pass through delivery pipe into condensor where due to the effect of circulating cold water, steam and oil vapours condense and the resulting mixture of water and essential oil is collected in the receiver or separator. Since the density of most of the essential oil is relatively lesser than water, theoil floats on water and can easily be taken out from the separator through the outlet provided specially for taking out oil.
  • This process is used in large scale production of essential oils from aromatic crops. The equipment (boiler, distillation tank, condenser and separator) needed for this process is expensive and needs technical personnel to run the boiler.

Field Distillation

  • In this process, the distillation tank is divided into two parts by fixing a mesh as a false bottom, below which water and above which harvested palnt material are filled.
  • The tank, closed with the lid and kept over a furnace constructed for the purpose, is fired using firewood or exhausted (distilled) plant material or weeds. The steam generated in the distillation tank carries with it the volatile essential oil in vapour form into the condenser through the delivery pipe.
  • The condensed liquid mixture of water and oil is collected in the separator. This process is used for small scale production of essentail oils and the equipment needed is relatively less expensive.
  • Central Institute of Medicinal and Aromatic Plants (CIMAP) has developed an improved field distillation unit which is easy in fabrication, cheaper in cost, easy ti instal, either in the farm or in a remote locality, fuel efficient and easy to use by unskilled or inexperienced persons. This distillation unit consists of the following parts:

Furnace and Chimney

The furnace is constructed with bricks and mud and is used for heating the distillation tank kept over it. This can be fired using firewood or exhausted plant material left after distillation or weeds. The chimney is made of mild steel and is useful for carrying the smoke coming out from furnace.

Distillation Tank or Retort

  • This is made of mild steel and is either cylindrical or rectangular in shape. The capscity of the tank is fixed based on the requirment.
  • A special mesh fixed in it divides it into two parts and facilitates filling of water below and plant material above the mean.
  • A fised, number of G.I pipes are welded at the bottom for increasing fuel efficiency.


  • The outer shell and legs are made of mild steel and the tubes inside the shell are made of aluminium. This is connected to the distillation tank with the help of a delivery pipe.
  • During distillation, cold water circulates in the condenser. The main purpose of the condenser is to condense the mixture of steam and oil vapour into water and essential all.

Receiver or Separator

  • This is made of aluminium and is used to collect the mixture of water and oil coming out from the condenser.
  • Separate outlets are provided for overflow of excess water and for taking out essential oil.

Storage and Packing of Essential Oil

  • Care is taken to ensure that the essential oil does not contain any water before storage. Amber coloured bottles are convenient for small quantities. For large quantities, steel or aluminium drums are widely used.
  • Ths oils are left to stand for sometimes so that water can settle down. If the oil is still turbid, a small amount of common salt is added and the oil filtered. The containers are filled up to the brim, tightly capped and stored in a cool, dry, dark place.
  • Exposure to air, light and water causes deterioration of the quality of essential oil.

Quality analysis

  • Identification and estimation of various constituents of essential oils is carried out by Gas chromatography.
  • Quality analysis of some of the important essential oils produced in Hyderabad is given below.

Oil of Citronella (Java)

Citronellal 50.9%
Geraniol 16.5%

Oil of Palmarosa

Geranyl acetate 11.2%
Geraniol 79.0%

Oil of Lemon Scented Gum

Citronellal 76.0%
Linalool 1.9%
Isopulegol 16.8%
Citronellol 5.5%

Oil of Lemongrass

Citral a 47.2%
Citral b 38.4%

Oil of Geranium

Isomenthone 5.3%
Linalool 7.9%
Rose oxides 0.9%
Citronelly formate 8.7%
Geranyl formate 6.3%
Citronellol 24.4%
Geraniol 20.5%
10-epi-y- eudesmol 3.8%

Oil of Davana

Davanone 42.2%

Uses, of Essential Oils and their Isolates

  • Essential oil is a complex mixture of odorous and steam volatile compounds of vegetable origin. The essential oils and their isolates are widely used in the following industries.

1. Soap and Cosmetics 2. Agarbatti
3. Tobacco 4. Soft drinks
5. Pharmaceuticals 6. Perfumery and Toiletery
7. Paint 8. Food flavouring
9. Chewing Gum 10. Confectionary etc.


Marketing Facilities for Essential Oils

Major Players and Oils Purchased

  • In A.P purchase activities are mostly concntrated in larger cities like Hyderabad and Vizag. The main regular purchasers are

    1.Navayuga Exports Limited
    2.S.H.Kelkar and Co.
    3.Sugandha Aromatics

  • Their areas of concentrations are as follows
  • M/s Navayuga Exports mostly purchase Lemongrass Oil, Citronella Oil and Palmarosa Oil. However, soon they intend to broaden the scope of their activities to cover other oils as well.
  • M/s S.H.Kelkar and Co. are more interrested in the higher value oils like Geranium and Patchouli. They do occasionally purchase other oils as well but that is comparatively rare.
  • M/s Sugandha Aromatics are concentrating mostly on Mint Oils.
  • Apart from these regular purchasers, there are occasional other buyers from out of the state who may come to fulfil a sudden requirement.

Purchase of Herbage

  • In and around Vizag, M/s Navayuga Exports Limited are willing to enter into herbage buy-back arrangements at minimum support prices with small farmers who may not be interested in putting up their own distillation units.
  • M/s S.H. Kelkar are entering into similar arrangements for patchouli etc.
  • Along with the buy-back arrangements, these companies provide seed material at discounted rates, advice on growing the crop as well as distillation and regular visits by their representatives to provide supervision.

Quality Issues

  • While purchasing, the buyer will obviously want to buy only the oil which matches his quality requirment.
  • Unfortunately, while most of the aromatic plant farmers in AP are very knowledgeable about the cultivation aspects, they ignore the quality aspect. They seem to be concerned only with Quantity.
  • Some major issues are

    1.The right distillation unit
    2.The right process of distillation
    3.Correct storage and handling

  • Please note that unless the right quality is produced, your buyer may not be able to pick up the oil.


  • Prices for aromatic oils are dictated by the demand and supply position in the market as well as quality of the soil.
  • In case of Peppermint Oil, indicative prices are published daily in the Economic Times and Hindu Business Line.
  • These are Delhi / Bombay prices. The purchaser in AP will buy as per these prices, plus or minus a small amount.
  • In case of the other oils, the fluctuation is not very high and most of the time you can be assured of selling your oil / herbage within a particular price range.

Risk factors

  • In the present year a large area has gone under cultivation of aromatic crops in A.P. Unfortunately, most of the people are concentrating on only one or two varieties. This may lead to over-production in the medium term.
  • For any farmer with more than 8-10 acres, it will make better sense to cultivate a variety of crops. This will spread the risks in case the market in any once crop drops.