570

13: Spices

Cinnamomum verum J.S. Presl

Prir. rostlin 2: 36—44. t. 7 (1825).

LAURACEAE

2n = 24

Laurus cinnamomum L. (1753), Cinnamomum zeylanicum Blume (1826).

Ceylon cinnamon, true cinnamon (En). Cannellier de Ceylon (Fr). Indonesia: kayu manis. Malaysia: kayu manis. Papua New Guinea: skin diwai. Philippines: cinnamon, kanela. Cambodia: che'k tum phka loëng. Vietnam: qu[ees] h[oof]i, qu[ees] r[af]nh, qu[ees] Srilanca.

Ceylon cinnamon occurs wild in south-west India, western Sri Lanka and the Tenasserim Hills of Burma (Myanmar). Cinnamon (and cassia) were among the first spices sought after by most 15th and 16th Century European explorers. The Portuguese, occupying Sri Lanka in 1536, and the Dutch, taking over in 1656, established virtual monopolies on the trade. From a product collected from wild stands, it became a cultivated crop in Sri Lanka around 1770. It was introduced into the Seychelles in 1771, where it easily naturalized and where a sizeable production developed. Cultivation in Java (Indonesia) began in 1825 but, after initial success, declined rapidly. Subsequently, Ceylon cinnamon has been taken to many countries. It is grown in southern India, the Seychelles and in Madagascar, but Sri Lanka continues to dominate the market.

The spice (Ceylon) cinnamon is the dried inner bark of Cinnamomum verum. The major uses of cinnamon, both in whole and ground form, are for domestic culinary purposes and for flavouring processed foods (bakery products, sauces, pickles, puddings, beverages, confectionery), in perfumes, pharmaceutical products and in incense. Cinnamon bark is an important folk medicine. Cinnamon bark is astringent, stimulant and carminative. It possesses the property of checking nausea and vomiting.
The bark can further be used for the distillation of bark oil and for the preparation of solvent-extracted oleoresin. The leaves are used for distillation of leaf oil, which has a different composition than bark oil.
The oleoresin is used mainly by the flavour industry in western Europe and North America for flavouring processed foods and in the soft-drink industry.
Cinnamon bark oil is used in flavouring (processed foods, beverages, dental and pharmaceutical preparations), much less in perfumery because it has some skin-sensitizing properties. As a powerful local stimulant it is sometimes prescribed in gastrodynia, flatulent colic and gastric debility. In European phytomedicine, cinnamon bark oil (0.05-0.2 g daily intake) is used in teas and other galenicals for its antibacterial, carminative, and fungistatic properties, and also for loss of appetite and dyspeptic disturbances. The maximum permitted level in food products is 0.06%.
Cinnamon leaf oil is used in flavouring and perfumery, and as a source of its major constituent eugenol. Eugenol is used for the synthesis of vanillin, and for conversion into iso-eugenol, used for flavouring confectionary products. Cinnamon leaf oil is extensively used as a fragrance component in soaps, detergents, cosmetic and alcoholic perfumery, with a maximum permitted level of 0.8% in the perfume.
In the United States the regulatory status 'generally recognized as safe' has been accorded to cinnamon (GRAS 2289), cinnamon bark oil (GRAS 2290/2291) and cinnamon leaf oil (GRAS 2292).
The seeds contain about 30% fixed oil, used in India for candle making. The oil is obtained by boiling crushed ripe fruits.
The timber is light to moderately heavy (specific gravity 0.5-0.7), usually straight-grained, even-textured, and weak. It seasons easily but warps, splits, cracks and stains. It is suitable only as low-grade board wood.

Sri Lanka produces the largest quantity and the best quality of bark of Ceylon cinnamon, mainly as quills. Total harvested areas in 1998 were estimated by FAO at 24 000 ha in Sri Lanka and 3400 ha in the Seychelles, producing respectively 12 000 t and 600 t. Exports are about 6000 t annually. Most cinnamon leaf oil also originates from these countries, whereas cinnamon bark oil and oleoresin are mainly prepared in the importing countries. From 1987-1992, Sri Lanka exported annually less than 3 t of bark oil, and about 115 t of leaf oil. The United States and western Europe are the main markets for these oils. Cinnamon bark oil is very expensive (1993: US$ 385/kg), reflecting the high raw material cost. Cinnamon leaf oil is much cheaper (1994: US$ 8.25/kg), but still more expensive than clove leaf oil (1994: US$ 2.70/kg), an alternative source of eugenol.

The dried inner bark of Ceylon cinnamon contains a steam-volatile oil, fixed oil, tannin, resin, proteins, cellulose, pentosans, mucilage, starch, calcium oxalate and minerals. The organoleptic properties are determined by the steam-volatile oil and the trace amounts of coumarin (non-steam-volatile). The essential-oil content of the bark varies from 0.5-2.0%.
Cinnamon oleoresin is a deep reddish or greenish brown viscous liquid, and contains the steam-volatile oil (16-65%), fixed oil, and other components dependent on the solvent. Ceylon cinnamon bark yields 10-12% oleoresin with ethanol as solvent, compared with 2.5-4.3% with benzene.
It is phytochemically interesting that the same tree produces 3 quite distinct essential oils, characterized by eugenol in the leaves, cinnamaldehyde in stem bark, and camphor in root bark.
Cinnamon bark oil is a pale-yellow liquid. Apart from 50-75% cinnamaldehyde, the important components (> 1%) include eugenol (5-18%), cinnamyl acetate, linalool, 1,8-cineole, 'BETA'-caryophyllene, and benzyl benzoate. The powerful characteristic note might be due to methyl-n-amylketone in combination with other aldehydes and ketones. Oil from bark chips is richer in eugenol (30-38%) and poorer in cinnamaldehyde (44%). Cinnamaldehyde is anesthetic, antipyretic, hypotensive, hypothermic and sedative.
Cinnamon leaves contain 0.7-1.2% essential oil. The leaf oil is yellow to brownish-yellow in colour. In composition it is more like clove oil. Apart from 70-95% eugenol (ISO: 75-85% phenols), important components (> 1%) include cinnamaldehyde (ISO: < 5%), benzyl benzoate, linalool, and 'BETA'-caryophyllene. Cinnamon leaf oil is of special interest for its antioxidant and antibacterial properties. Eugenol is strongly antiseptic.
Cinnamon root bark contains 1-2.8 % of a colourless to pale yellowish-brown oil, which has no commercial importance. The major component is camphor (60%), which crystallizes on standing.
Monographs on the physiological properties of cinnamon bark oil and cinnamon leaf oil have been published by the Research Institute for Fragrance Materials (RIFM).

Cinnamon and cassia barks are interchangeable in many applications, and the same applies to cinnamon bark oil, cassia bark oils and (Chinese) cassia leaf oil. Adulteration with synthetic cinnamaldehyde is simple and mainly a function of the price of the natural product. However, detection methods have much improved, and adulteration is becoming less common.
As a source of eugenol, cinnamon leaf oil has lost ground to the cheaper clove leaf oil, except when the eugenol is needed for conversion into iso-eugenol (used in confectionary products).

Evergreen tree up to 18 m tall; bole low-branching, up to 60 cm in diameter; buttresses 60 cm tall, 70 cm deep, thin, light pinkish-brown; bark about 10 mm thick, strongly aromatic; the bark on young shoots is smooth and pale brown, on mature branches and stems rough, dark brown or brownish-grey; oil cells are located in the phloem, and are oval or round in cross- section; wood of mature trees varies from light brownish-grey to grey or yellowish-brown, without markings, more or less lustrous and faintly scented. Leaves opposite, somewhat variable in form and size, strongly aromatic; petiole 1-2 cm long, grooved on upper surface; blade ovate to elliptical, 5-25 cm x 3-10 cm, conspicously 3-veined, or 5-veined, base rounded, apex acuminate, glabrous, coriaceceous, shiny dark green. Inflorescence consisting of lax axillary or terminal panicles up to 10 cm long or longer; peduncle creamy white, softly hairy, 5-7 cm long; flowers small, 3 mm in diameter, with foetid smell, pale yellow, subtended by small ovate hairy bract; perianth 8 mm long, silky hairy, with short campanulate tube and 6 persistent tepals about 3 mm long; fertile stamens 9, in 3 whorls, with 2 small glands at the base of the stamens of the 3rd whorl; a fourth innermost whorl consists of 3 staminodes; filaments hairy, stout; anthers 4- or 2-celled; ovary superior, 1-celled, with a single ovule, style short. Fruit a 1-seeded berry, ellipsoidal to ovoid, 1-2 cm long, black when ripe, surrounded by the enlarged perianth at the base.

Ceylon cinnamon produces moderately deep and extensive roots. Seedling root growth is initially rapid, with formation of a well-developed taproot followed by numerous spreading laterals. There is normally a single central stem, but in cultivation trees are coppiced. The uncut tree has numerous, often drooping, branches beginning low on the trunk. Growth takes place in flushes, young leaves being reddish in colour, later turning dark green. Pollination is most probably by insects, especially flies. Fruits mature in 6 months.

In Sri Lanka several wild and semi-wild types and local cultivars are recognized, with distinctive local names. Distinction is mainly based on aroma and therefore location-specific.

Ceylon cinnamon requires a warm and per-humid climate with a well-distributed annual rainfall of 2000-2500 mm, and average temperatures of about 27°C. It grows best at low altitudes, and is usually grown without shade, but being essentially a forest tree, light shade does no harm. The type of soil has a pronounced effect on bark quality. Fine sandy and lateritic gravelly soils rather than rocky and stony substrates are best in Sri Lanka and India, but in the Seychelles and Madagascar more loamy soils are preferred. Ceylon cinnamon is considered susceptible to salinity. A bitter product results from waterlogged and marshy conditions.

Propagation is by seed or by vegetative means. Fruits are much liked by birds and the seed is easily spread, so the fruits have to be bagged for collection. Fruit pulp is allowed to rot before seeds are removed, washed and dried. Seeds quickly lose their viability. Fresh seeds germinate in 20-25 days. They are sown in nurseries or directly in the field. The nursery bed (1 m wide) should have a well-prepared rich sandy soil and be lightly shaded. Seeds are sown close together. Clumps of seedlings are transferred into bags after 4 months in the nursery and transplanted to the field after another 4-5 months. Five or more seedlings are always planted closely together in a small circle, developing into an indiscriminate clump.
Vegetative propagation is by cuttings, layering or division of old rootstocks. Young cuttings with 2-3 nodes are planted in polybags and placed under polythene cover; they are ready for field planting after 12-18 months. Old rootstocks can be divided. For this, old plants are cut down to within 15 cm of the ground, and suitable parts of the rootstock planted out with adhering soil. Harvesting can start 1-1.5 years after planting out in the field compared with 3 years for seedlings. Modern micropropagation methods have also been successfully applied to produce large numbers of plantlets.
Field spacings of 0.9-1.2 m x 0.9-1.2 m are recommended in Sri Lanka for commercial plantations, but wider planting up to 3 m x 3 m is also practised with a higher number of plants per clump.

After-planting care mainly consists of weeding, 2-4 times a year. Stems are kept straight by pruning. Manure or plant residues are commonly applied as fertilizer, but chemical fertilizers, although recommended, are little used. Placing phosphate in the planting holes is advantageous, single superphosphate being preferable because of the small amounts of sulphur it contains. Annual application of a 2 : 1.5 : 1.5 mixture of urea, rock phosphate and potassium chloride is recommended at a rate of 40-60 kg/ha to young trees, and 100 kg/ha to mature trees. A nitrogenous top dressing at the beginning of the rainy season is advisable for quick (re)growth of (coppiced) trees. It is advisable to return processing residues to the field as mulch. Plants are coppiced for the first time after 2 years, the stem being cut to within 10-15 cm from the ground and covered with earth, allowing 4-6 shoots per stool to grow for a further 2 years before harvesting. After harvesting, all unwanted shoots and stumps are cut off the stool, which is then covered with earth, and new shoots are allowed to grow. The number of shoots per stool normally increases to a maximum at 8 years and declines after 10-12 years. A cinnamon plantation can remain profitable for 15-45 years, mainly depending on the standard of management.

Stripe canker (Phytophthora cinnamomi) may damage trunks and branches of young trees in particular. Symptoms are vertical strips of dead bark, particularly near ground level. Root rots include black rot caused by Rosellinia spp., brown rot by Phellinus lamaensis, and white rot by Fomes lignosus. Pink disease (Corticium salmonicolor, syn. Corticium javanicum) causes pink encrustations on the stem with death of small shoots. Glomerella cingulata causes anthracnose. Rust (Aecidium cinnamomi) and other leaf and stem diseases (Cephaleuros virescens, Diplodia spp., Exobasidium spp., Gloeosporium spp., Leptosphaeria spp., Pestalotia cinnamomi) may occasionally cause damage.
In India and Sri Lanka, caterpillars of the cinnamon butterfly (Chilasa clytia) are destructive to new flushes, and shothole borers (Xylosandrus spp.) cause damage to stem and bark. Leaf miners (Acrocercops spp., Phyllocnistis chrysophthalma), gall and leaf mites (Eriophyes bois, Eriophyes doctersi, Typhlodromus spp.), leaf webbers (Sorolopha archimedias) and arboreal ants (Oecophylla smaragdina) cause occasional damage. Young seedlings are vulnerable to damage by agrotid larvae or mole crickets (Gryllotalpa spp.), and larvae of Popillia spp., attacking roots. Ceylon cinnamon is also attacked by root-knot nematodes (Meloidogyne spp.). Storage pests of cinnamon quills include Lasioderma serricorne, Pyralis farinalis and Sitodrepa panicea.

Ceylon cinnamon has to be harvested during the wet season because then the cambium is active and the cortex can be easily separated from the wood. The shoots are harvested when they are 2-3 m tall and 1.2-5.0 cm in diameter. Shoots in the centre of the clump are cut low down, while those on the outside are cut higher up to ensure that new buds sprout mainly on the outside of the clump. In Sri Lanka harvest peaks are in May-June and October-November. The first harvest is of inferior quality (thick bark), but this improves in later harvests. Best quality cinnamon is obtained from thin bark from the middle part of shoots in the centre of the stool. Leaves and twigs are cut off and used for mulching, or the leaves are retained for distillation. The harvested shoots are bundled and taken to a processing unit for peeling and further preparation.

The first crop, 3-4 years after planting, yields 50-120 kg/ha of quills, increasing in subsequent crops to 175-250 kg/ha, before yields decline after 10-12 years. Commercial cinnamon bark is not more than 0.5 cm thick and is of a dull pale brown colour. The inner surface is somewhat darker than the outer one and is finely striated longitudinally. By-products of the production of quills are cinnamon chips (averaging 60 kg/ha) and leaves (2.5 t/ha fresh weight). Large individual trees may yield up to 45 kg of dry bark. Average annual bark yields of 120 kg/ha have been reported for the Seychelles, and an annual yield of fresh leaves of about 1.9 t/ha, yielding 0.6-0.8% leaf oil (11-16 kg/ha). Leaf-oil yields of 35-40 kg/ha have also been reported.

Peeling consists of stripping the bark for the preparation of quills from the inner bark. The outer bark is first removed and the stem then rubbed to loosen the inner bark. Two horizontal cuts are made 30 cm apart and two longitudinal slits on opposite sides of the shoot. The inner bark is then separated from the wood. Alternatively, the outer and inner bark are separated from the wood together. The strips are packed together, wrapped and left overnight for slight fermentation, facilitating the subsequent scraping off of the outer bark (epidermis, cork and green cortex). The curled pieces are assembled into compound quills of 1 m length by joining the best and longest quills on the outside and smaller pieces inside the longer ones. They are dried in the shade until they are yellowish-brown. They are sometimes bleached by sulphur treatment. The grading of Ceylon cinnamon is rather elaborate compared with the grading of cinnamon from other sources. The various forms and qualities are known as unscraped bark, scraped bark, compound quills, simple quills, quillings (broken pieces of quills), featherings (bark of twigs and twisted shoots) and chips (trimmings, shavings). Quills are further graded according to the thickness of the bark. Grinding usually takes place in the consuming countries.
Bark to be distilled for oil should not be allowed to become damp, as this encourages mould or fermentation, which affects oil composition. Bark oil is obtained by steam or hydro-distillation with cohobation, or solvent extraction of the distillate. Solvent extraction of the distillate gives the finest quality oil.
Leaves stripped from shoots, together with small leafy twigs and stems are left in the field for 3-4 days and then transported to the distillery.
Root bark oil is only produced when a plantation is uprooted for replanting. Roots are cleaned, trimmed and peeled prior to distilling.

There are no germplasm collections of Cinnamomum verum. Little improvement work has been done. Since Cinnamomum is open-pollinated, selection, together with vegetative propagation of clonal material would be advantageous. Some selection for superior strains is carried out in Sri Lanka and the Seychelles.

The demand for the spice cinnamon (and cassia) has always been satisfactory, and the prospects are still promising, as the competition from synthetic alternatives does not noticeably affect the trade. Consumption is likely to be mainly a function of population growth. The prospects for the essential oils seem to be less bright, as there are many alternatives.

Coppen, J.J.W., 1995. Flavours and fragrances of plant origin. Non-wood Forest Products 1. FAO, Rome, Italy. pp. 7-17.
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M. Flach & J.S. Siemonsma

Flach, M. & Siemonsma, J.S., 1999. Cinnamomum verum J.S. Presl. In: de Guzman, C.C. and Siemonsma, J.S. (Editors): Plant Resources of South-East Asia No 13: Spices. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea