71

13: Spices

Aleurites moluccana (L.) Willd.

Sp. pl. 4: 590 (1805).

EUPHORBIACEAE

2n = 22, 24, 44

Jatropha moluccana L. (1753), Aleurites triloba J.R. & G. Forst. (1776), Juglans camirium Lour. (1790).

Candlenut tree, Indian walnut, lumbang tree (En). Noix des Indes, noix de Bancoul, noix des Moluques (Fr). Indonesia: kemiri (general), miri (general), muncang (Sundanese). Malaysia: kemiri, kembiri, buah keras. Papua New Guinea: tutui. Philippines: lumbang, biaw (Cebuano). Laos: kôk namz man. Thailand: phothisat (Bangkok), kue-ra, purat (peninsular), mayao (northern). Vietnam: lai.

The origin of Aleurites moluccana is not accurately known, but it is distributed from India and China, throughout South-East Asia, to Polynesia and New Zealand. It has been introduced for cultivation in many tropical countries all over the world.

The seed of Aleurites moluccana ('kemiri') is an indispensable spice in Indonesian cuisine, possessing little flavour of its own, but mainly acting as an enhancer. Raw, or briefly roasted, it is added to numerous dishes in small quantities, pounded and mixed with other ingredients. Raw seed is slightly poisonous, acting as a laxative.
The fatty seed oil (lumbang oil) is used industrially (in paints, varnishes, linoleum, soap manufacture, wood preservation), for illumination (lamp oil, candles) and medicinally (mild purgative, embrocation for sciatica, against hair loss), but not for cooking. The oil is also used in the batik industry. For illumination, the oily kernels can be burnt as such, or pounded and made into candles.
In Indonesia the residual oil cake is sometimes processed into a snack-food called 'dage kemiri': the oil cake is pounded, soaked for 48 hours in running water, steamed, and stored for 48 hours in a dark place to ferment (covered with a banana leaf with a weight on top of it to press out remaining liquid). The oil cake is an excellent organic fertilizer rich in N and P, but is not recommended as animal feed because of its toxic effects. Aleurites moluccana is a commonly planted tree in villages, and is also used for reafforestation. It grows well in fields infested with sedge and can help suppress the weed.
The wood is rather light and not very durable. Though not used for construction, it is used to make furniture, small utensils and matches where it is abundant. It is suitable for paper pulp.
In traditional medicine the seed is used as a laxative, pulped kernels are used in poultices to treat headache, fevers, ulcers, swollen joints and constipation, the bark is used to treat dysentery, the bark sap (mixed with coconut milk) to treat sprue, a decoction of young leaves to treat scrophulosis, and boiled leaves are applied externally to treat headache and gonorrhoea.
The hardness of the 'nut' (seed surrounded by the hard endocarp shell) is exploited in a gambling game in which the objective is to break the opponent's 'nut' by hitting it with one's own. In Indonesia a special cultivar supplies oval thick-walled 'nuts' for this ('kemiri pidak', 'muncang kelenteng').

In Indonesia, there is a considerable internal trade in kemiri nuts, mainly with Java as the destination. In the late 1980s, annual exports of kemiri were in the order of 400-600 t with a total value of US$ 200 000-500 000. Kemiri is traded and transported as 'nuts'. At the retail level, small quantities of kemiri are marketed as seed (hard endocarp removed).
Early in the 20th Century, some seed oil (lumbang oil) was exported from the Philippines to the United States for industrial use in paints and soaps.

Per 100 g edible portion, dry seed of Aleurites moluccana contains: water 5-8 g, protein 8-22 g, fat 60-62 g, carbohydrates 7-18 g, fibre 2-3 g, ash 3-4 g. The energy value is about 2675 kJ/100 g. Possessing very little flavour of its own, it seems that kemiri mainly acts as a flavour enhancer, making our taste buds temporarily more sensitive.
The fatty component (cold-pressed) is a drying oil, light yellow in colour, with agreeable flavour and smell. When left to stand, it dries in thin films. The main characteristics are a high iodine value (115-170 g/100 g) and a high saponification value (184-227 mg K per g oil). The content of free fatty acids is very low; glycerides of saturated acids form 2%, and glycerides of unsaturated acids 96% (oleic acid 40%, linoleic acid 48%, linolenic acid 8%).
The moderate toxicity of the seed has been ascribed to a toxalbumin similar to the ones in Abrus Adans. and Ricinus L.
The 'nut' weight is 10-14 g; it is made up of shell (endocarp) for 65-70%, and seed (kernel) for 30-35%.

Kemiri can be used as a substitute for 'santen' ('milk' pressed from grated coconut in water). Lumbang oil strongly resembles linseed oil (Linum usitatissimum L.), and either oil can be used as a substitute for the other.

Large, evergreen, monoecious tree, 10-40 m tall, with heavy, irregular, large-leafed crown appearing whitish or frosted from a distance due to a cover of white stellate hairs especially on young parts; stem diameter up to 1.5 m, bark grey, rather rough with lenticels. Leaves alternate, simple; stipules small, early caducous; petiole up to 30 cm long, bearing a pair of small, green-brown glands at the top on the upper side; blade in young trees and suckers subcircular in outline, up to 30 cm in diameter, with a cordate base and 3-5 triangular lobes; blade in adult trees ovate-triangular or ovate-oblong, 12-23 cm x 6-12 cm, margin entire or slightly sinuate, apex pointed, curved and drooping, dark green with a silvery gloss. Inflorescence thyrsoid, terminal or upper-axillary, 10-20 cm long; flowers unisexual, on a small pedicel, white, female flowers terminating the ultimate branchlets of the cymes, male flowers much more numerous, smaller, opening earlier, arranged around the female flowers in bunches; calyx 2-3-lobed at anthesis; petals 5, lanceolate, 6-7 mm long in male flowers, 9-10 mm in female ones; disk glands 5; male flowers with 10-20 stamens, arranged in 3-4 series, the outer ones free, the inner ones connate; female flowers with 2-4-locular, tomentose ovary and 2-4, deeply bipartite styles. Fruit drupaceous, laterally compressed, ovoid-globose and 2-seeded or semiglobose and 1-seeded, 5-6 cm x 4-7 cm, tomentose, indehiscent, olive-green with whitish flesh. Seed compressed-globose, up to 3 cm x 3 cm; endocarp thick, bony, rough; albumen thick, rich in oil.

Aleurites moluccana first flowers when it is about 4 years old. Flowering can occur year-round. Fruits need 3-4 months to develop and mature. In the Philippines, trees reached 12.5 m in height and 15 cm in diameter, in 8 years.

Aleurites J.R. & G. Forst. is a small genus of only 2 species since Aleurites sensu lato has been split up into 3 genera:
- Aleurites J.R. & G. Forst., comprising Aleurites moluccana and Aleurites remyi Sherff, the latter only occurring in Hawaii;
- Reutealis Airy Shaw, comprising Reutealis trisperma (Blanco) Airy Shaw (syn. Aleurites trisperma Blanco), used for oil production in the Philippines;
- Vernicia Lour., comprising Vernicia cordata (Thunb.) Airy Shaw (syn. Aleurites cordata (Thunb.) Muell. Arg.), Vernicia fordii (Hemsl.) Airy Shaw (syn. Aleurites fordii Hemsl.), and Vernicia montana Lour. (syn. Aleurites montana (Lour.) Wilson). Vernicia montana and Vernicia fordii yield the well-known tung oil.
Var. floccosa Airy Shaw, occurring in New Guinea, is distinguished on the basis of a much more copious subfloccose stellate indumentum, contrasting with the minute smooth covering of typical Aleurites moluccana, and in having 3-4-locular ovaries instead of bilocular ones.

Aleurites moluccana occurs commonly in the drier regions of South-East Asia. In the more humid parts it is found naturally in rather specific locations, such as well-drained sands near the coast and on limestone, but it is also present naturalized in mixed and teak forests, at altitudes up to 1200 m.

Propagation of Aleurites moluccana is usually by seed, but vegetative propagation, e.g. by marcotting, seems possible. The hard-shelled seeds retain their viability for over a year. The hard shell, however, is also the cause of uneven and often strongly delayed germination. Germination percentage is usually low (30-40%), but can be improved significantly by scarification: mechanical, physical (successive heating and cooling), or chemical (HSO¦, HNO).
Seeds are sown in a seedbed or in polythene bags at a depth of 3-10 cm. In the field the planting distance is about 10 m x 10 m when grown for seed, whereas closer spacings of 4 m x 4 m are applied if pulp-wood is the main objective.

Established seedlings require little tending. The leaves are renewed regularly, and old leaves left on the soil soon rot, enriching the soil with organic matter and nutrients.

A root-collar disease caused by Ustulina deusta (syns. Ustulina maxima, Ustulina vulgaris, Ustulina zonata) has been observed on Aleurites moluccana in Indonesia. Botryodiplodia theobromae has been found to infest the wood, causing blue stain.
No pests of economic importance occur.

Fruits of Aleurites moluccana are allowed to fall and lie on the ground until the outer fruit wall has decayed, after which the 'nuts' (hard-shelled seeds) are collected.

Yield estimates of Aleurites moluccana vary from 2500-15 000 'nuts' per tree per year, or 25-150 kg (at a 'nut'-weight of 10 g). This corresponds to 8-50 kg kernels per tree per year, or 5-30 kg oil per tree per year.

Since it is difficult to crack the 'nuts' of Aleurites moluccana, a combination of mechanical (hammering) and physical (successive heating and cooling) methods is usually applied. The best quality 'nuts' for use as a spice are obtained by sun-drying for 5-10 days, followed by mechanical cracking.
'Nuts' may be stored for over a year without appreciable change in the amount and composition of the oil. Seeds (kernels) cannot be stored for long, since they are attacked by small beetles, and the oil acidifies.
The use of an oil mill for crushing and grinding the whole 'nuts' and pressing the oil, gives a low oil yield and the oil cake is of less value as organic fertilizer.

A living collection of Aleurites moluccana is maintained by the Research Institute for Spice and Medicinal Crops (RISMC), Bogor, Indonesia. No breeding programmes are known to exist for Aleurites moluccana.

The value of kemiri as a spice is uncontested. Only if tree stocks considerably increase, e.g. as a result of use in reafforestation and agroforestry, might there be sufficient raw material for significant oil production. The oil produced might find a use in applications that currently use imported linseed oil or petrochemicals. However, it is still doubtful whether this is economically viable. The use of the wood in the paper industry might become a major application in the long term.

Airy Shaw, H.K., 1966. Notes on Malaysian and other Asiatic Euphorbiaceae. Kew Bulletin 20: 393-395.
Airy Shaw, H.K., 1980. The Euphorbiaceae of New Guinea. Kew Bulletin Additional Series 8: 25-26.
Corner, E.J.H., 1988. Wayside trees of Malaya. Vol. 1. 3rd edition. The Malayan Nature Society, Kuala Lumpur, Malaysia. pp. 265-266.
Hadad, M.E.A. & Mansur, M., 1992. Plasma nutfah kemiri di Balai Penelitian Tanaman Rempah dan Obat [Candlenut-tree germplasm at the Research Institute for Spice and Medicinal Crops]. Proceedings of the National Seminar on Research and Development of Multi-purpose Trees, Cisarua, Bogor, Indonesia, 16-17 June 1992. pp. 249-254.
Semangun, H., 1988. Penyakit-penyakit tanaman perkebunan di Indonesia [Diseases of estate crops in Indonesia]. Gadjah Mada University Press, Yogyakarta, Indonesia. p. 335.
Tapa Darma, I.G.K., 1993. Identifikasi jamur 'blue stain' yang menyerang berbagai jenis kayu [Identification of the blue-stain fungus attacking several timber species]. Technical Notes, Faculty of Forestry, Bogor Agricultural University 5(1): 27-32.

J.S. Siemonsma

Siemonsma, J.S., 1999. Aleurites moluccana (L.) Willd.. 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