Presentation on theme: "VOLATILE OILS. All official volatile oils are of vegetable origin. Normally pre-exist in the plant – stored in a special secretory tissue (e.g. Citrus."— Presentation transcript:
All official volatile oils are of vegetable origin. Normally pre-exist in the plant – stored in a special secretory tissue (e.g. Citrus peel oil cells or oil ducts in umbelliferous fruits). EXCEPTION: Oil of bitter almond – formed by hydrolysis of the glycosides.
USES OF VOLATILE OILS Therapeutically (Oil of Eucalyptus) Therapeutically (Oil of Eucalyptus) Flavouring (Oil of Lemon) Flavouring (Oil of Lemon) Perfumery (Oil of Rose) Perfumery (Oil of Rose) Starting materials to synthesize other compounds (Oil of Turpentine) Starting materials to synthesize other compounds (Oil of Turpentine) Anti-septic – due to high phenols (Oil of Thyme). Also as a preservative (oils interfere with bacterial respiration) Anti-septic – due to high phenols (Oil of Thyme). Also as a preservative (oils interfere with bacterial respiration) Anti-spasmodic (Ginger, Lemon balm, Rosemary, Peppermint, Chamomile, Fennel, Caraway) Anti-spasmodic (Ginger, Lemon balm, Rosemary, Peppermint, Chamomile, Fennel, Caraway) Aromatherapy Aromatherapy
DEFINITION OF VOLATILE OILS Volatile oils are products which are generally complex in composition, consisting of the volatile principles contained in plants, and are more or less modified during the preparation process. Only 2 procedures may be used to prepare official oils i. Steam distillation ii. Expression 4 Main types of volatile oils i. Concretes ii. Pomades iii. Resinoids iv. Absolutes
CONCRETES Prepared from raw materials of vegetable origin (bark, flowers, leafs, roots etc.) Extracted by HC type solvents, rather than distillation or expression – Becomes necessary when the essential oil is adversely affected by hot water or steam (e.g. jasmine). Produces a more true-to-nature fragrance.
CONCRETES Concretes contain about 50 % wax and 50 % essential oil (jasmine). Ylang ylang (concrete volatile) contains 80 % essential oil and 20 % wax. Advantages of concretes: they are more stable and concentrated than pure essential oils.
POMADES True pomades are (volatile oil) products of a process known as enfleurage (hot or cold). Enfleurage is used for obtaining aromatic materials from flowers containing volatile oils to produce perfume long after they were cut.
ENFLEURAGE: METHOD A glass plate is covered with a thin coating of especially prepared and odourless fat (called a chassis). The freshly cut flowers are individually laid on to the fat which in time becomes saturated with their essential oils. The flowers are renewed with fresh material. Eventually the fragrance-saturated fat, known as pomade, may be treated with alcohol to extract the oil from the fat.
RESINOIDS Prepared from natural resinous material (dried material) by extraction with a non-aqueous solvent, e.g. Petroleum ether or hexane. E.g. Balsams – Peru balsam or benzoin; resins (amber or mastic); Oleoresin (copaiba balsam and turpentine); Oleogum resins (frankincense and myrrh)
RESINOIDS Can be viscous liquids, semi-solid or solid. Usually homogeneous mass of non- crystalline character. Uses: in perfumery as fixatives to prolong the effect of a fragrance.
ABSOLUTES Obtained from a concrete, pomade, or a resinoid by alcoholic extraction. The extraction process may be repeated. The ethanol solution is cooled & filtered to eliminate waxes. The ethanol is then removed by distillation. They are usually highly concentrated viscous liquids.
Fx OF VOLATILE OILS In most cases, the biological function of the terpenoids of essential oils remains obscure – it is thought that they play an ecological role – protection from predators & attraction of pollinators.
LOCALIZATION Synthesis & accumulation of essential oils are generally associated with the presence of specialized histological structures, often located on or near the surface of the plant: - Oil cells of Zingiberaceae - Oil cells of Zingiberaceae - Glandular trichomes of Lamiaceae - Secretory cavities of Myrtaceae or Rutaceae - Secretory canals of Apiaceae or Astereraceae (Compositeae) - Secretory canals of Apiaceae or Astereraceae (Compositeae)
VOLATILE OIL COMPOSITION Mixtures of HCs and oxygenated compounds derived from these HCs. Mixtures of HCs and oxygenated compounds derived from these HCs. Oil of turpentine – mainly HCs Oil of turpentine – mainly HCs Oil of Clove – mainly oxygenated compounds Oil of Clove – mainly oxygenated compounds EXCEPTION: Oils derived from glycosides (e.g. bitter almond oil & mustard oil). EXCEPTION: Oils derived from glycosides (e.g. bitter almond oil & mustard oil). Oxygenated compounds – responsible for the odour/smell of the oil. They are slightly water soluble – Rose water & Orange Water; more alcohol soluble. Oxygenated compounds – responsible for the odour/smell of the oil. They are slightly water soluble – Rose water & Orange Water; more alcohol soluble. Most volatile oils are terpenoid. Some are aromatic (benzene) derivatives mixed with terpenes. Most volatile oils are terpenoid. Some are aromatic (benzene) derivatives mixed with terpenes. Some compounds are aromatic, but terpenoid in origin (e.g. Thymol – Thyme) Some compounds are aromatic, but terpenoid in origin (e.g. Thymol – Thyme)
CHEMICAL COMPOSITION Volatile oils are divided into 2 main classes based on their biosynthetic origin i. Terpene derivatives (formed via the acetate mevalonic acid pathway) ii. Aromatic compounds (formed via the shikimic acid-phenylpropanoid route) iii. Miscellaneous Origin
A. TERPENES Terpenes, or terpenoids, are the largest group of secondary products (metabolites). They are all formed from acetyl CoA or glycolytic intermediates.
CLASSIFICATION OF TERPENES All terpenes are formed from 5-C elements Isoprene is the basic structural element.
CLASSIFICATION OF TERPENES Terpenes are classified by the number of 5-C atoms they contain 10-Carbon terpenes (contain 2 C-5 units) – monoterpenes 15- Carbon terpenes (3 C-5 units) are called sesquiterpenes. 20-carbon terpenes (4 C-5 units) are diterpenes. Larger terpenes (30 Carbons) are called triterpenes (triterpenoids), 40 Carbons – called tetraterpenes and polyterpenoids.
TERPENOIDS Terpenoids contain only the most volatile terpenes (i.e. molecular weight is not too high) mono and sesquiterpenes May occur as oxygenated derivatives, e.g. alcohols, aldehydes, ketones, phenols, oxides & esters.
EXAMPLES OF TERPENES i. LIMONENE ii. MENTHOL iii. BORNEOL iv. SESQUITERPENES
i. LIMONENE Structural classification: Monocyclic terpene Functional Classification: Unsaturated HC Occurrence: Citrus fruit
ii. MENTHOL Structural classification: Monocyclic with hydroxyl group Functional classification: Alcohol Occurrence: Peppermint
iii. BORNEOL Functional Classification: //// Occurrence: Cinnamon
iv. SESQUITERPENES (Contain 3 isoprene units) Acyclic – E.g. Farnesol Monocyclic – E.g. Bisobolol Bicyclic e.g. Chamezulene (Chamomile)
B. AROMATIC COMPOUNDS Many are phenols are phenol esters E.g. Vanillin
PROPERTIES OF VOLATILE OILS Almost entirely volatile without decomposition. Almost entirely volatile without decomposition. Density: Most are less than 1g/ml. Density: Most are less than 1g/ml. 2 are heavier – Oil of Cinnamon and Clove oil. 2 are heavier – Oil of Cinnamon and Clove oil. Soluble in ether, chloroform & alcohol. Soluble in ether, chloroform & alcohol. Slightly soluble in water: give it a characteristic odour & taste. Slightly soluble in water: give it a characteristic odour & taste. Leaves a temporary translucent stain on paper which disappears as the oil volatilizes. Leaves a temporary translucent stain on paper which disappears as the oil volatilizes. Most are colourless. Oxidize on exposure to air and resinify colour becomes darker (odour changes slightly). Most are colourless. Oxidize on exposure to air and resinify colour becomes darker (odour changes slightly). All are characteristic odours. All are characteristic odours. Most are optically active. Most are optically active.
PRODUCTION OF ESSENTIAL OILS Essential oils may be produced i. By steam - Simple steam distillation - Saturated steam distillation - Hydrodiffusion i. By expression ii. Other Methods Concretes & Resinoids may be produced i. By solvent extraction ii. By methods using oils & fats iii. By extraction by supercritical gasses
ESSENTIAL OILS: i.STEAM DISTILLATION a. SIMPLE STEAM DISTILLATION Plant material is immersed directly in a still filled with water. This is then brought to a boil. Heterogeneous vapours are condensed on a cold surface. Essential oil separates based on difference in density and immiscibility.
b. SATURATED STEAM Plant does not come into contact with the water steam is injected through the plant material placed on perforated trays. It is possible to operate under moderate pressure. Advantages: Limits the alteration of the constituents of the oil It shortens the duration of the treatment It conserves energy It can also be conducted on on-line in automated set ups.
c. HYDRODIFFUSION Pulses of steam is sent through the plant material at very low pressure from (top to bottom). ADVANTAGE: Normally produces a product of high quality. Saves time and energy.
ii.EXPRESSION (E.G.OF CITRUS EPICARPS) The rind is lacerated, and the contents of the ruptured secretory cavities are recovered. CLASSIC PROCESS: an abrasive action is applied on the surface of the fruit in a flow of water. The solid waste is eliminated, and the essential oil separated from the aqueous phase by centrifugation. OTHER machines break the cavities by depression, and collect the essential oil directly prevents the degradation linked to the action of water.
EXPRESSION OF CITRUS EPICARPS Most facilities allow for the simultaneous or sequential recovery of the fruit juice and of the essential oil, by collecting the oil with a spray of water after the abrasion (scarification – puncture by pins) before or during the expression of the fruit juice. Enzymatic treatment of the residual water allows recycling, and markedly increases the final yield of essential oil. Citrus oils are also obtained directly from the fruit juices (by vacuum de-oiling)
iii. OTHER METHODS - Steam distillation by microwaves under vacuum. In this procedure, the plant is heated selectively by microwave radiation in a chamber inside which the pressure is reduced sequentially. - fresh plants require no added water. - ADVANTAGE: This method is fast, consumes little energy and yields a product which is most often of a higher quality than the traditional steam distillation product.
PRODUCTION OF CONCRETES & RESINOIDS i. SOLVENT EXTRACTION Extraction is generally preceded by a process of: bruising the fresh, wilted or semi-desiccated organs, chopping herbaceous drugs, pounding roots & rhizomes or turning wood into chips or shavings. The procedure is conducted in specialized facilities e.g. Soxhlet-type extractor.
SOLVENT EXTRACTION The solvent selection is influenced by technical & economical factors - Selectivity (being a good solvent for the specific constituents). - Stability (chemical inertness) - Boiling point should not be so high that the solvent can be completely eliminated; nor too low, to limit losses & control cost - Boiling point should not be so high that the solvent can be completely eliminated; nor too low, to limit losses & control cost - Handling safety Solvents most used are aliphatic HCs – petroleum ether, hexane, propane & liquid butane. Although benzene is a good solvent, its toxicity increasingly limits is use.
SOLVENT EXTRACTION At the end of the procedure, the solvent contained in the plant material is recovered by steam injection. Main disadvantages of solvent extraction - Lack of selectivity, many lipophilic substances may end up in the concretes & render further purification necessary. - The toxicity of solvents leads to the restrictive regulations regarding their use - Residues in the final product.
ii. METHODS USING OILS & FATS These procedures take advantage of the liposolubility of the fragrant components of plants in fats. a. Enfleurage – the plant material is placed in contact with the surface of the fat. Extraction is achieved by - Cold diffusion into the fat - Digestion – carried out with heat, by immersing the plant in melted fat (also known as hot enfleurage). The final product is known as a floral pomade.
METHODS USING OILS & FATS b. PNEUMATIC METHOD: similar in principle to the enfleurage process. It involves the passage of a current of hot air through the flowers. The air, laden with suspended (extracted) volatile oil, is then passed through a spray of melted fat in which the volatile oil is absorbed.
iii. EXTRACTION BY SUPERCRITICAL GASSES Beyond its critical point, a fluid can have the density of a liquid & the viscosity of a gas therefore diffuses well through solids, resulting in a good solvent. CO2 is the main gas used Advantages of CO2 - It is a natural product - chemically inert, non-flammable - non-toxic - easy to completely eliminate - selective - readily available - Inexpensive
EXTRACTION BY SUPERCRITICAL GASSES DISADVANTAGE: Technical constraints - High cost of initial investment ADVANTAGES: - obtain extracts which are very close in composition to the natural product. - It is possible to adjust the selectivity & viscosity, etc by fine tuning the temperature & pressure - All result in the increase of popularity of this type of method
EXTRACTION BY SUPERCRITICAL GASSES USES Initially developed to decaffeinate coffees, prepare hops extracts or to remove nicotine from tobacco, the method is now used to - Prepare spice extracts (ginger, paprika, celery) - Specific flavours (black tea, oak wood smoke) - Plant oils - To produce specified types of a certain product, e.g. thujoneless wormwood oil.
TREATMENTS OF THE OILS Occasionally it is necessary to decolourize, neutralize or rectify the oils obtained. i. Steam jet under vacuum Allows for the elimination of smelly or irritating products, and to obtain a final product of desired profile. ii. Chromatrographic techniques This permits a good separation of the essential oil from non-volatile lipophilic compounds.
VARIABILITY FACTORS OF ESSENTIAL OILS i. Occurrence of Chemotypes ii. Influence of the vegetative cycle iii. Influence of environmental factors iv. Influence of preparation method
i. CHEMOTYPES Chemical breeds commonly occur in plants containing volatile oils, e.g. Thyme (Thymus vulgaris) – has 7 different chemotypes, each with slightly different types & amounts of volatile oils.
ii. THE VEGETATIVE CYCLE Proportions of the different constituents of a volatile oil may vary greatly throughout its development. Wide ranges are commonly found in fennel, carrot and coriander (linalool is higher in ripe fruit than unripe fruit). Mentha (peppermint) is also greatly affected by the vegetative cycle.
iii. ENVIRONMENTAL FACTORS Temperature, humidity, duration of daylight (radiation), and wind patterns all have a direct influence on volatile oil content, especially in those herbs that have superficial histological storage structures (e.g. glandular trichomes). When the localization is deeper, the oil quality is more constant.
ENVIRONMENTAL FACTORS e.g. Peppermint: long days & temperate nights higher yields of oil & menthofuran. Cold nights lead to an increase in menthol. Laurus nobilis (Bay) [volatile oil] is greater in the southern hemisphere than the northern. Citrus: higher temperatures = higher oil content.
ENVIRONMENTAL FACTORS Cultivation practices also play an important factor to the yield & quality of the final product. Fertilization and the amounts of N, P and K have been studied for various species. The watering regiment also plays an important role.
PREPARATION METHOD Because of the volatile nature of the constituents of essential oils, the composition of the product obtained by steam distillation is often different from the constituents originally found in the secretory organs of the plant. During steam distillation, the water, acidity and tempereature may induce hydrolysis of the esters. Rearrangements, isomerizations, racemiazations, oxidations and other reactions also occur, all of which change the composition.
GINGER: Zingiber officinale Definition: Ginger is the peeled or unpeeled rhizome of Zingiber officinale (Zingiberaceae). Definition: Ginger is the peeled or unpeeled rhizome of Zingiber officinale (Zingiberaceae). Common Names: Jamaican ginger, Ginger Common Names: Jamaican ginger, Ginger
Zingiber officinalis - Ginger GEOGRAPHICAL SOURCES Jamaica Jamaica China China India Africa India AfricaHISTORY Cultivated in India from the earliest times. Used by Greeks and Romans and was a common article of commerce in the European Middle Ages.
CULTIVATION & PREPARATION Grows well in subtropical temperatures with high rainfall. Grows well in subtropical temperatures with high rainfall. Grown by vegetative means. Grown by vegetative means. Mulching or is necessary as the plant rapidly exhausts minerals from the soil. Mulching or is necessary as the plant rapidly exhausts minerals from the soil. When the stems wither, the rhizomes are ready for collection. When the stems wither, the rhizomes are ready for collection. Dried. Dried.
MACROSCOPICAL FEATURES Scraped/peeled herb has little resemblance to the fresh herb (loss in weight & shrinkage). Scraped/peeled herb has little resemblance to the fresh herb (loss in weight & shrinkage). Occurs in branched pieces hands or races. Occurs in branched pieces hands or races. Buds Buds No cork No cork Aromatic odour & pungent taste. Aromatic odour & pungent taste. Unscraped rhizome: resembles scraped herb – Unscraped rhizome: resembles scraped herb – Covered with cork (brownish layers) Covered with cork (brownish layers)
MICROSCOPICAL FEATURES Cork cells – high starch content Cork cells – high starch content Cork cells are absent in the scraped drug. Cork cells are absent in the scraped drug. Outer zone of flattened parenchyma & inner zone of normal parenchyma. Outer zone of flattened parenchyma & inner zone of normal parenchyma. Oil cells scattered in the cortex. Oil cells scattered in the cortex.
Zingiber officinale VARIETIES VARIETIES Chinese Ginger – sliced Chinese Ginger – sliced African ginger – darker (cortex is grey – black in colour); lacks the odour but more pungent than Jamaican herb. African ginger – darker (cortex is grey – black in colour); lacks the odour but more pungent than Jamaican herb. ALLIED DRUGS ALLIED DRUGS Japanese ginger – Z. mioga Japanese ginger – Z. mioga Preserved ginger – undried rhizomes preserved by boiling in syrup. Preserved ginger – undried rhizomes preserved by boiling in syrup. ADULTERANTS ADULTERANTS Spent ginger Spent ginger Vegetable adulterants (detected with microscopical examination). Vegetable adulterants (detected with microscopical examination).
CARDAMOM FRUIT & OIL DEFINITION: Cardamom consists of the dried, nearly dried ripe fruits of Elettaria cardamomum var miniscula (Zingiberaceae). PARTS USED: Seeds (should be kept in the fruit until ready to be used – Prevents loss of volatile oils). (3 RD most expensive spice).
Elettaria cardamomum GEOGRAPHICAL SOURCES GEOGRAPHICAL SOURCES Sri Lanka Sri Lanka India India Guatemala Guatemala HISTORY HISTORY Traditional Indian ceremonies Traditional Indian ceremonies
PRODUCTION, COLLECTION & PREPARATION Mainly obtained from cultivated plants (propagated by seedlings or vegetatively [problematic due to virus infection]). Mainly obtained from cultivated plants (propagated by seedlings or vegetatively [problematic due to virus infection]). Capsules on the same plant ripen at different times – important to collect them before they split. Capsules on the same plant ripen at different times – important to collect them before they split.
COLLECTION & PREPARATION Fruits are dried slowly (outdoors or indoors). Fruits are dried slowly (outdoors or indoors). Too rapid drying – capsules split & shed seeds Too rapid drying – capsules split & shed seeds Calyx at the apex of the stalk and the stalk at the base may be removed. Calyx at the apex of the stalk and the stalk at the base may be removed. Fruits are graded with a sift into longs, mediums, shorts & tiny. Fruits are graded with a sift into longs, mediums, shorts & tiny. If they have been sulphur – bleached (improved colour), it will be aired outdoors before packed for transport. If they have been sulphur – bleached (improved colour), it will be aired outdoors before packed for transport.
MACROSCOPICAL FEATURES Plant is reed-like - > 4 m, with long leaves growing from the rhizome. Plant is reed-like - > 4 m, with long leaves growing from the rhizome. Fruits – capsular: inferior, ovoid, 1-2 cm long. Fruits – capsular: inferior, ovoid, 1-2 cm long. Apex: shortly beaked & shows floral remains. Apex: shortly beaked & shows floral remains. Base: rounded & shows the remain of a stalk. Base: rounded & shows the remain of a stalk. Internally the capsule is 3-celled; each cell contains x2 row of seeds. Internally the capsule is 3-celled; each cell contains x2 row of seeds. Each seed: Slightly angular, 4mm long & 3 mm broad. Each seed: Slightly angular, 4mm long & 3 mm broad. Colour: dark red-brown (fully ripe seeds) paler in unripe seeds. Colour: dark red-brown (fully ripe seeds) paler in unripe seeds. Strong, pleasant, aromatic odour Strong, pleasant, aromatic odour Pungent taste Pungent taste
VARIETIES & ADULTERANTS ADULTERATION ADULTERATION Powdered drug adulterated with the fruit pericarp (powdered). Powdered drug adulterated with the fruit pericarp (powdered). ALLIED HERBS ALLIED HERBS Official variety – E. cardamomum var miniscula Official variety – E. cardamomum var miniscula Other: E. cardamomum var major (more elongated & sometimes 4 cm long with dark brown pericarps) Other: E. cardamomum var major (more elongated & sometimes 4 cm long with dark brown pericarps) Amomum aromaticum (Bengal cardamom) Amomum aromaticum (Bengal cardamom) Amomum subulatum (Nepal cardamom) Amomum subulatum (Nepal cardamom) Amomum cardamomum (Java cardamom) Amomum cardamomum (Java cardamom)
Elettaria: ACTIONS & USES Flavouring agent (curries & biscuits) Flavouring agent (curries & biscuits) Liqueur manufacture Liqueur manufacture Small amount is used for pharmaceutical manufacture (Compound Tincture of Cardamom). Small amount is used for pharmaceutical manufacture (Compound Tincture of Cardamom).
CINNAMON: Cinnamomum zeylanicum DEFINITION: Cinnamon is the dried bark of Cinnamomum zeylanicum (Lauraceae). DEFINITION: Cinnamon is the dried bark of Cinnamomum zeylanicum (Lauraceae). GEOGRAPHICAL SOURCES GEOGRAPHICAL SOURCES Cultivated in Sri Lanka, South India, Seychelles, Madagascar, Martinique, Cayenne, Jamaica & Brazil.
CULTIVATION, COLLECTION & PREPARATION Grown from seed Cut down when 2-3 years old. After 5-6 shoots grow from the stump (18 months), shoots are harvested, trimmed and fermented. Bark is removed. Peeled bark is then stretched over a suitable stick Outer cortex is removed.
PREPARATION OF Cinnamomum Individually scraped barks are placed inside each other. Compound quills are dried on wooden frames in the open air without exposure to direct sunlight. Sorted into grades.
MACROSCOPICAL FEATURES Normally received in shorter lengths known as cigar lengths. Consists of a single or double compound quill about 6-10 mm diameter of varying length. Thickness of the quill varies according to grade (good quality: Not > 0.5mm), bark: 10-40mm. External surface: is yellow-brown, shining, wavy lines (pericycle fibres) and occasional scars & holes (leave/twig positions). Inner surface: darker, longitudinally striated. Odour: fragrant Taste: Warm, sweet & aromatic
MICROSCOPICAL FEATURES Transverse: absence of epidermis & cork Transverse: absence of epidermis & cork Sclereids (thickened lignified pitted walls) Sclereids (thickened lignified pitted walls) Secondary phloem is composed of phloem parenchyma containing oil & mucilage cells, phloem fibres & medullary rays. Secondary phloem is composed of phloem parenchyma containing oil & mucilage cells, phloem fibres & medullary rays. Some phloem parenchyma contain tannins. Some phloem parenchyma contain tannins. Secretion cells: volatile oils and mucilage Secretion cells: volatile oils and mucilage Calcium oxalates Calcium oxalates
CINNAMON OIL – ADULTERATION & ALLIED HERBS Adulterants Cinnamon Leaf Oil Cinnamon Leaf Oil Oil of Cassia Oil of Cassia Allied Herbs Cayenne Cinnamon – C. zeylanicum grown in Brazil – not used in Britain Cayenne Cinnamon – C. zeylanicum grown in Brazil – not used in Britain C. loureirii – from Vietnam – Closely resembles C. cassia C. loureirii – from Vietnam – Closely resembles C. cassia
LEMON PEEL Definition: Dried lemon (Limonis Cortex) peel is obtained from the fruit of Citrus limon (Rutaceae). Botanical Description: Small tree, growing to 3-5 m in height. Geographical Sources Mediterranean Regions
Limonis Cortex – COLLECTION & PREPARATION Lemons are collected in January, August & November, before the green colour changes to yellow. The smaller fruit, which would not be sold on the produce market, are used in the preparation of oil of lemon - the peel is removed with a sharp knife in the form of a spiral band.
Limonis Cortex – CHARACTERISTICS Dried lemon peel occurs in spiral bands (2 cm wide; 2-3 mm thick). The outer surface is rough & yellow; the inner surface is pulpy & white (anatomically similar to that of an orange peel). Odour: Strong & characteristic Taste: aromatic & bitter
Limonis Cortex – CONSTITUENTS & USES CONSTITUENTS Should contain at least 2.5% volatile oil Vitamin C Hesperidin (Flavonoid) Mucilage Calcium Oxalate USES Flavouring purposes
LEMON OILS - Oleum limonis Definition: Lemon oil is the oil expressed from the outer part of the fresh pericarp of the ripe or nearly ripe fruit of Citrus limon (Rutaceae). BP: oil should be obtained by suitable mechanical means, without the use of heat, from the fresh peel. Much oil is derived via steam distillation, but this process yields oil of inferior quality. Distilled oil of lemon is much cheaper than that prepared by expression. Large amounts are used for non-pharmaceutical purposes. Geographical Sources: Mediterranean, North & South America, Australia & parts of Africa.
Preparation of Lemon Oils i. Hand Methods No longer applicable to pharmaceutical oils
Production of Lemon Oils ii. Machine Processes Quality is inferior to the best hand-pressed oils. Machines are designed to release oils from the peel via puncture, rasting or cutting and by imitating the gentle squeezing action of the sponge method. (Superiority of the sponge method is due to the fact that there is no contact between the oil & the inner white part of the skin. The newer machines extract oil more completely than the older ones and give a higher yeild iii. Distilled Oils Although not official, some lemon oils are produced by distillation, mainly from the residue of the expression processes. It is much cheaper than hand-pressed or machine-made oil.
Oleum limonis - CONSTITUENTS Terpenes – mainly limonene Sesquiterpenes Aldehydes (Citral & Citronella) Esters Lemon oil has a tendency to resinify and should be protected from the action of air & light as much as possible.
Oleum limonis – ADULTATION & USES ADULTERATION Oil of turpentine Terpenes from terpeneless oil of lemon Distilled oil of lemon Oil of lemon-grass USESPerfumeryFlavouring
TERPENELESS LEMON OIL Definition: Oil prepared by concentrating lemon oil in vacuum until most of the terpenes have been removed, or by solvent partition. The concentrate is a terpeneless oil, which has a citral content of %. It is equal in flavouring to times its volume of lemon oil
BUCHU – Agathosma betulina
Agathosma betulina – CONSTITUENS & USES CONSTITUENTS Volatile oils Pulegone Pulegone Menthone & isomenthone Menthone & isomenthone limonene limoneneDiosminMucilageResin Calcium oxalates Buchu camphor – Responsible for the diuretic action USES/ACTIONSDiuretic Urinary Tract Anti-Septic – Used for UTIs
NUTMEG & NUTMEG OIL Definition: Nutmeg is the dried kernel of the seed of Myristica fragrans (Myristicaceae). Geographical Sources Indigenous to the Molucca Islands (Spice Islands) Cultivated in Indonesia, Malaysia & the West Indies.
NUTMEG – Myristica fragrans HISTORY First Introduced to the Europeans by the Arabs. Portuguese lost control of the spice trade to the Dutch, who maintained complete monopoly by destroying all trees in the neighbouring islands & preventing the export of living seeds.
CULTIVATION, COLLECTION & PREPARATION Trees can be grown from fresh seed gown in the shell. The seeds germinate after about 5 weeks. When the plants are 6 months old, they are transplanted to the fields. Nutmegs are dried in the shells (process differs according to local conditions). Normally they are dried in the sun & covered at night & rainy weather. They can also be dried in the oven or over low flames. When completely dried, the kernel rattles in the testa, which is then cracked & the nutmeg extracted.
MACROSCOPICAL FEATURES Nutmeg trees are evergreen, growing up to 20 m in height. Nutmegs are oval, 2-3 cm long & 2 cm broad. If not heavily limed, the surface is a brown or grey brown in colour. Odour: Strong & aromatic Taste: Pungent and slightly bitter.
MICROSCOPICAL FEATURES Potassium acid tartrate crystals Parenchym with thin brown walls Oval oil cells Feathery crystals of fat Few tannin cells (containing tannin & starch)
NUTMEG – ALLIED HERBS Papua nutmegs – from M. argentea (New Guinea) – little odour & a disagreeable taste. Bombay nutmegs – M. malabarica (India) – lack the characteristic odour of the genuine herb.
NUTMEG OIL Nutmeg oil is distilled from the kernels of Myristica fragrans. CONSTITUENTSPineneSabineneCampheneDipenteneSafrole Eugenol & eugenol derivatives Myristicin – a benzene: toxic to humans (large does of nutmeg or nutmeg oil may cause convulsions).
MACE Common mace or Banda mace consists of the dried arillus or arillode of M. fragrans. Description: bright red colour & lacks in aroma.
MACE – CONSTITUENTS & USES CONSTITUENTS Volatile oils (similar to that of nutmeg) – eugenol derivatives are the main active constituents – responsible for the anti- bacterial effects. Also has 2 anti-microbial resorcinols (Malabaricone B and C) Nutmegs, maces & their oils, are all used for Carminatives Carminatives Flavouring Flavouring Infantile Diarrhoea (Tea of nutmeg – Ayurveda). Infantile Diarrhoea (Tea of nutmeg – Ayurveda).
CLOVE DEFINITION: Cloves are the dried flower buds of Syzygium aromaticum (Eugenia caryophyllus), (Myrtaceaea). Geographical Sources Molucca or Clove Islands, Zanzibar, Pemba, Madagascar, Indonesia & Brazil.
HISTORY OF CLOVE Cloves were used in China as early as 266 BC, and by the 4 th century, they were known in Europe, although very expensive. Same as with nutmeg, the Dutch also destroyed all trees from surrounding native islands to secure a monopoly, and cultivated them only in a small group of islands. In 1770, the French managed to introduce clove trees to Mauritius, and started cultivating them there, as well as in Zanzibar, Penang and Sumatra.
COLLECTION & PREPARATION The flower buds are collected when the lower part turns green-crimson. The cloves are dried in the open air on mats & separated from their peduncles (forming clove stalks which are also sold commercially). If left on the tree for too long, the buds open & the petals fall, leaving brown cloves. Later the fruits (mother cloves) are produced.
MACROSCOPICAL FEATURES Cloves are mm long. The head consists of 4 slightly projecting calyx teeth, 4 membranous petals and numerous incurved stamens around a large style. Odour: Spicy & Pungent Taste: Aromatic
MICROSCOPICAL FEATURES Heavy cuticularized epidermis Numerous oil cells (shizolysigenous) Calcium oxalates (cluster crystals & prisms) Stomata (epidermis of sepals) Starch (Fruit – mother cloves) Lignified sclereids
USES OF CLOVE Stimulant aromatic Spice For the preparation of volatile oil Sesquiterpenes: potential anti- carcinogenic compounds
CLOVE OIL Oil distilled in Europe and the US normally does not need purification, while oil distilled in other areas (e.g. Madagascar) does. After purification the oil is sold with varying eugenol contents. Oil of cloves is yellow or colourless, is slightly heavier than water.
CLOVE OIL - CONSTITUENTS Volatile oils – mainly eugenol & acetyleugenol Sesquiterpenes (α and β caryophyllenes) Oil of clove – like other volatile/essential oils – should be stored in a well-fitted, air-tight container, & should be protected from light & heat.
EUCALYPTUS LEAF DEFINTION: Eucalyptus leaf consists of the whole or cut dried leaves of the older branches of Eucalyptus globulus, (Myrtaceae). GEOGRAPHICAL SOURCES Portugal, SA, Spain, China, Brazil, Australia, India & Paraguay.
Eucalyptus - DESCRIPTION MACROSCOPICAL Older dried leaves are grey-brown & have lateral veins. Secretory oil cells are visible in leaves held to the light. Older dried leaves are grey-brown & have lateral veins. Secretory oil cells are visible in leaves held to the light.MICROSCOPIC Epidermal cells have a thick cuticle. Epidermal cells have a thick cuticle. Anisocytic stomata Anisocytic stomata Mesophyll has schizogenous oil glands Mesophyll has schizogenous oil glands Calcium oxalate crystals: Prisms & Cluster crystals Calcium oxalate crystals: Prisms & Cluster crystals
Eucalyptus - CONSTITUENTS Volatile Oil (at least 2 %) sesquiterpene - Anti- bacterial action against oral pathogens.
EUCALYPTUS OIL Oil of eucalyptus is distilled from the fresh leaves of various species of Eucalyptus and rectified. They are produced in the same countries which produce the dry herb. Only a certain amount of species produce oil suitable for medicinal use – the main criteria is a high cineole content and low amounts of phellandrene and aldehydes. Suitable oils are obtained from E. polybractea, E. smithii, E. globulus and E. australiana.
CHARACTERISTICS & CONSTITUENTS CHARACTERISTICS Colourless or pale yellow liquid Aromatic & camphoraceous in odour. Pungent & camphoraceous in taste, which is followed by a sensation of cold. CONSTITUENTS At least 70 volatile oils (mainly cineole). At least 70 volatile oils (mainly cineole).
EUCALYPTUS OIL - USES Alleviating the symptoms of nasopharyngeal infections Treating coughs Decongestant. Official preparations Mixtures, inhalations, lozenges and pastilles; also applied externally as ointments and liniments.
FENNEL DEFINITION: Fennel consists of the dried ripe fruits of Foeniculum vulgare (Umbelliferae). GEOGRAPHICAL SOURCES Europe, India, China & Egypt. Mediterranean origin.
ACTIONS & USES ACTIONS Carminative Carminative Expectorant Expectorant Aromatic Aromatic - All due to anethole (and fenchone) USESFlatulenceDyspepsia Chronic coughs & catarrh
Foeniculum vulgare – USES Culinary purposes Used in medicine as a flavouring Carminative
CARAWAY & CARAWAY OIL DEFINITION: Caraway consists of the dried, ripe fruits of Caram carvi (Umbelliferae). GEOGRAPHICAL SOURCES Wild & Cultivated in Central & Northern Europe, Holland, Denmark, Germany, Russia, Finland, Poland, Hungary, Britain, Egypt, Morocco, Australia & China
MACROSCOPICAL FEATURES A biennial herb growing up to 1 m in height. Herb: Normally consists of mericarps separated from the pedicels. Fruits are slightly curved, brown & glabrous. Size: 4-7 mm long, 1-3 mm wide Often the stigma & style are still attached. Characteristic aromatic odour & taste
MICROSCOPICAL FEATURES Pitted sclerenchyma secretory canals Dark, red-brown cells containing a pale yellow or colourless oleoresin Thick cellulose walls Calcium oxalate crystals
CORIANDER & CORIANDER OIL DEFINITION: Coriander is the dried, nearly ripe fruit of Coriandrum sativum (Umbelliferae). GEOGRAPHICAL SOURCES Indigenous to Italy. Also cultivated in Holland, Central & Eastern Europe, Mediterranean (Morocco, Malta & Egypt), China, India & Bagladesh. Indigenous to Italy. Also cultivated in Holland, Central & Eastern Europe, Mediterranean (Morocco, Malta & Egypt), China, India & Bagladesh.
MACROSCOPICAL FEATURES Annual herb growing 0.7 m in height with white or pink flowers. Drug: Normally consists of whole cremocarps – straw yellow & 2-4 mm in diameter when ripe. Considerable variation occurs (e.g. Indian variety > oval). Apex has 2 styles. Fruits have an aromatic odour & spicy taste. Unripe plant: unpleasant mousy odour same odour oil has when made from unripe fruit.
MICROSCOPICAL FEATURES Outer pericarp: stomata & calcium oxalte prisms. Thick sclerenchyma Testa:= brown flattened cells Endosperm is curved & consists of parenchymous cells containing fixed oils.
PEPPERMINT & PEPPERMINT OIL DEFINITION: Peppermint is the dried leaves of Mentha piperita (Labiate). It should contain at least 1.2 % volatile oil. GEOGRAPHICAL SOURCES: Europe & America
MACROSCOPICAL FEATURES All mints have a square stem & creeping rhizome. Black mint, which is the most commonly cultivated variety in England, has purple stems and dark green petiolate leaves tinged with purple. Leaf blades are 3-9 cm long with a grooved petiolate up to 1 cm long. Black mint, which is the most commonly cultivated variety in England, has purple stems and dark green petiolate leaves tinged with purple. Leaf blades are 3-9 cm long with a grooved petiolate up to 1 cm long. Pinnate venation. Pinnate venation. Glandular trichomes: bright yellow points (hand lens) Small purple flowers appear in late summer.
MICROSCOPIC FEATURES Diacytic stomata Multicellular clothing trichomes 2 types of glandular trichomes (one with a unicellar head; with a multicellular head). Calcium oxalate is absent.
Oleum Menthae Oil of peppermint is obtained from Mentha piperita via steam distillation using the flowering tops. Oil should contain at least 44 % menthol, & menthone and % menthyl acetate.
LESSON TAKE-AWAY Definitions of Volatile Oils Definitions of Volatile Oils Methods of Production of Volatile Oils Methods of Production of Volatile Oils Herbs containing Volatile Oils Herbs containing Volatile Oils