Benzoin (FAO, NWFP 6)

← Dragon's blood

Coppen, Gums, resins and latexes of plant origin, 1995

Styrax →

• See the main page Benzoin (in French)

• Extract from : NWFP 6. Coppen J.J.W., 1995. Gums, resins and latexes of plant origin. FAO, Rome. 142 p. (Non-Wood Forest Products, 6). on line

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5 — SOFT RESINS AND BALSAMS

BENZOIN

DESCRIPTION AND USES

Benzoin is a balsam obtained from trees of the genus Styrax from Southeast Asia. There are two types of benzoin of commerce: Siam benzoin from Styrax tonkinensis and Sumatra benzoin (also called gum Benjamin) from Styrax benzoin.

When freshly collected, Siam benzoin is a semi-solid material but it soon hardens to form brittle tears or pebble-shaped pieces, often translucent, and yellowish-red to brown in colour. Sumatra benzoin also hardens to form solid tears. However, both types (but particularly Sumatra benzoin) often enter trade as solid blocks comprising whitish tears embedded in a matrix of reddish-brown resin (often made from damar dust).

In common with other balsams, both types of benzoin contain mixtures of either predominantly benzoic acid and its esters and other derivatives (Siam benzoin), or cinnamic acid and its derivatives (Sumatra benzoin), and these confer on benzoin the characteristic balsamic odour. The lower grades of Sumatra benzoin have a harsher note.

A range of tinctures, "resinoids" and "absolutes" are produced by extraction of the balsam with suitable hydrocarbon or alcoholic solvents and these are the form in which benzoin is usually employed in its end-uses. Unlike many other balsams, benzoin produces negligible amounts of essential oil on distillation.

Both types of benzoin have extensive fragrance applications but the higher quality of the Siam benzoin enables it to be used in the more expensive, delicate perfumes. In the areas where it is produced, benzoin is also traded as an incense.

Sumatra benzoin (and, to a lesser extent, Siam benzoin) is used quite widely in pharmaceutical preparations: as an ingredient of inhalations for the treatment of catarrh and in topical preparations for its antiseptic and protective properties. Benzoin is also used in traditional Chinese medicine.

WORLD SUPPLY AND DEMAND TRENDS

Markets

Siam benzoin

Information provided by PINYOPUSARERK (1994) indicates that production of Siam benzoin in Laos in 1948 was 50 tonnes which, at that time, almost entirely satisfied world demand. Current (1994) production was said to be significantly less than 50 tonnes, although it was suggested that this figure might rise as a result of French interest in securing long-term supplies of 40 tonnes annually. A recent estimate by de BEER (1993) put Laotian production at rather more than this, over 100 tonnes/year (exported to France and the People's Republic of China); Vietnamese exports were estimated at 10 tonnes/year (to France).

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Exports of [Siam] benzoin from Thailand (see below) are small, so total world demand for benzoin of this type appears to be between 50 tonnes and 120 tonnes annually, with Europe (and France in particular) being the biggest market.

Sumatra benzoin

Exports of benzoin from Indonesia for the period 1988-93, and their destinations, are given in Table 23. Note that in the Indonesian trade statistics, what is taken to be benzoin (see footnote to Table 23) is classified as "frankincense".

The data in Table 23 show no clear trend but the annual average for the six years is approximately 960 tonnes. This is considerably more than the 100-150 tonnes estimated in 1971 for production of Sumatra benzoin (ADAMSON, 1971), and indicates either that there has been a substantial increase in demand for benzoin in the 20 years since then; or that exports of Indonesian frankincense (if they were recorded in 1971) were not identified as being those of benzoin; or that what is presently recorded as frankincense is not all benzoin.

Whatever the case, the final destinations of most of the exports indicated in Table 23 are not known - most of the benzoin is shipped to Singapore. However, a large proportion of this can be presumed to go on to Europe for both fragrance and pharmaceutical use; some of it might also go to the People's Republic of China for medicinal use. Other, direct importers of Indonesian benzoin are Japan and countries in the Middle East and the Indian subcontinent.

Supply sources

Laos has been noted above as being the major producer of Siam benzoin, with smaller quantities coming from Viet Nam. Recent exports of [Siam] benzoin from Thailand are shown in Table 24, although Thai production is believed to originate from Laos; exports for 1988-93 averaged 10 tonnes/year.

Indonesia is the only producer of Sumatra benzoin and production may be at, or above, the level of exports given in Table 23.

Quality and prices

Siam benzoin is regarded as being of a much higher quality than Sumatra benzoin. The latter is more likely to be sold in the form of block benzoin (see above) and this has led to a very variable quality, with widespread adulteration through the inclusion in the blocks of pieces of damar resin. In India, samples of benzoin from the local market have been found to be adulterated with pine rosin.

Both types of benzoin used to be included in the British Pharmacopoeia (BP, 1980), for which a minimum content of 25% total balsamic acids was required (calculated as benzoic acid for Siam benzoin and cinnamic acid for Sumatra benzoin). The amount of (90%) ethanol-insoluble matter allowable was less for Siam benzoin (not more than 5%) than Sumatra benzoin (not more than 20%). The most recent British Pharmacopoeia (BP, 1993) only describes Sumatra benzoin; included in the specification is a test for checking the absence of damar.

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An FAO specification for "Benzoin gum" describes requirements of both types of benzoin for use as a flavouring agent.

The highest grade of benzoin is sold as separate pieces called "Almonds". Blocks of benzoin are usually sold under trade names which vary in quality and price; one such brand of Sumatran benzoin was priced at about US$ 2 500/tonne in mid-1995 (CIF London).

PLANT SOURCES

Botanical/common names

Family Styracaceae:

• Styrax tonkinensis (Pierre) Craib ex Hartwiss (syn. Styrax tonkinense Pierre)
• Styrax benzoin Dryand.
• Styrax paralleloneurus Perkins

The balsam from Styrax tonkinensis is known as Siam benzoin. Balsam from Styrax benzoin and Styrax paralleloneurus is known as Sumatra benzoin (or, less commonly, as gum Benjamin). In Indonesia, Sumatra benzoin is called frankincense, although this term is usually taken to mean the resinous exudate from Boswellia spp. of Arabia and Africa.

Other Styrax spp. are tapped for balsam locally but the products are not believed to enter world trade (for example, Styrax hypoglauca Perk. (Accepted name : Styrax tonkinensis) and Styrax cascarifolia (Accepted name : Styrax casearifolia ?) in the People's Republic of China).

Description and distribution

Styrax tonkinensis is a tree up to 25 m tall and 30 cm in diameter, with a clear bole for about two thirds of the tree's height. It occurs naturally in the northern parts of Laos and Viet Nam, mainly in secondary rainforests, but its fast-growing nature and suitable fibre properties have led to it being grown as a plantation species for pulp production. The species has also been introduced into southern parts of the People's Republic of China. Styrax benzoin occurs wild in Sumatra, Indonesia, and the Malay Peninsula, but is also cultivated on hillsides or dry rice land.

COLLECTION/PRIMARY PROCESSING

Methods of tapping Styrax tonkinensis in Laos have recently been described (PINYOPUSARERK, 1994). The tapper makes a notch 8-10 cm wide and 5-6 cm long into the cambium of the trunk and the bark removed. A number of incisions are made, staggered at intervals of 20-30 cm along the trunk. The lower incisions are made about 30 cm from the ground; the higher ones at the level of the first branches. Sometimes the incisions are made up to a height of 2 m only; a new 2 m section is then tapped the following year. The exuded oleoresin is left on the tree to harden, and it may be as long as 4-5 months after tapping (during the first cold days of winter) that the tears of benzoin are picked from the tree.

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The first tapping is made on trees 3-5 years of age in natural forests and trees 6-8 years old in regenerated forests. Tapping continues for up to 6-8 years; it may be less if bark removal is excessive and permanent damage is done to the tree.

After collection, villagers undertake some hand cleaning and sorting, removing pieces of bark but taking particular care to retain (and not break) whole tears.

Collection of Sumatra benzoin from Styrax benzoin is presumed to be carried out in much the same way as that described above for Styrax tonkinensis.

Yields

In Laos, average annual yields of 1-3 kg of balsam per tree are reported to be obtained, although there is much tree-to-tree variation. It has been observed that trees having thin, light-coloured, smooth bark yield less benzoin than those with thick, dark brown, deeply fissured bark.

VALUE-ADDED PROCESSING

A number of tinctures, "resinoids" and "absolutes" are produced by extraction of the balsam with suitable hydrocarbon or alcoholic solvents and these are used by end-user industries in the formulation of fragrances and pharmaceutical preparations.

PRODUCTS OTHER THAN RESIN

The cultivation of Styrax tonkinensis in Viet Nam for pulp production has already been referred to. Over 50 000 ha have been established and the current planting rate is 3000 ha/year; the rotation is 10 years. In the People's Republic of China, Styrax tonkinensis is cultivated for both wood and balsam production.

DEVELOPMENTAL POTENTIAL

In Laos, collection of benzoin is an important cottage industry and widely practised by highland people, despite the relatively small size of the industry. If the figures for Indonesian exports cited earlier are correct, then an even larger number of people are involved in benzoin production in that country. Details are not available on the scale of cultivation of Styrax benzoin in Indonesia, but if it is anything approaching that of Styrax tonkinensis in Viet Nam, and if oleoresin production were coupled with wood production, then the potential for increased production of both types of benzoin is considerable. Whether this could be realized in practice depends on whether the international market can use more benzoin and, if so, whether the price to both the collector and the end-user is attractive enough to encourage increased production.

Research needs

If an appreciable amount of benzoin comes from cultivated sources, or it is sought to increase this proportion, then the economics of production could benefit greatly from the use of superior planting stock (in terms of oleoresin quality and yields). In this case, a screening programme aimed at identifying such material from different provenances of wild trees is desirable.

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SELECTED BIBLIOGRAPHY

• ADAMSON, A.D. (1971) Oleoresins. Production and Markets with Particular Reference to the United Kingdom. Report G56. London: Tropical Products Institute [now Natural Resources Institute, Chatham].
• De BEER, J.H. (1993) Benzoin, Styrax tonkinensis. p 17. In Non-Wood Forest Products in Indochina. Focus: Viet Nam. FAO Working Paper FO:Misc/93/5. Rome: FAO.
• BOELENS, H.M., de RIJKE, D. and HARING, H.G. (1982) Studies of some balsamics in perfumery. Perfumer and Flavorist, 6(6), 7-14.
• BP (1980) Siam benzoin/Sumatra benzoin. pp 51-53. In British Pharmacopoeia, Vol. 1. London: Her Majesty's Stationery Office.
• BP (1993) Sumatra benzoin. p 75. In British Pharmacopoeia, Vol. 1. London: Her Majesty's Stationery Office.
• DEN, X.Q., CHENG, S.P., PAN, N.X. and CHEN, J.L. (1978) [The effects of ethrel upon benzoin production and balsamic ducts of Styrax hypoglauca Perk.] (in Chinese, English summary). Acta Botanica Sinica, 20(1), 26-30.
• FAO (1992) Benzoin gum [published in FAO Nutrition Meeting Report Series 57, 1977]. pp 187-188. In Compendium of Food Additive Specifications. FAO Food and Nutrition Paper 52 (Joint FAO/WHO Expert Committee on Food Additives. Combined Specifications from 1st through the 37th Meetings, 1956-1990). Rome: Food and Agriculture Organization.
• HELLIWELL, K. and JENNINGS, P. (1983) A critical evaluation of commercial Sumatra benzoins. Journal of Pharmacy and Pharmacology, 35(Supplement), 17P.
• KETPHANH, S. (1994) Benzoin (Styrax tonkinensis). pp 5-7. In Country Paper of Lao. Paper presented at Regional Expert Consultation on Non-Wood Forest Products: Social, Economic and Cultural Dimensions, 28 Nov.- 2 Dec., 1994, Bangkok. Bangkok: FAO Regional Office for Asia and the Pacific.
• PINYOPUSARERK, K. (1994) Styrax Tonkinensis: Taxonomy, Ecology, Silviculture and Uses. ACIAR Technical Report 31. 14pp. Canberra: Australian Centre for International Agricultural Research.
• SHAH, C.S., QADRY, J.S. and SHAH, B.K. (1971) Evaluation of market samples of benzoin. The Indian Journal of Pharmacy, 33(6), 119-120.
• SILITONGA, T. (1994) Indonesia. pp 49-54. In Non-Wood Forest Products in Asia. 161 pp. Bangkok: FAO Regional Office for Asia and the Pacific.

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Table 23. Benzoin: exports from Indonesia, and destinations, 1988-93 (tonnes)

	1988	1989	1990	1991	1992	1993
Total	1157	975	884	1126	806	824
Of which to:
Singapore	1099	881	773	1062	735	780
Malaysia	7	36	27	17	39	7
China (Taiwan)	21	30	-	14	-	12
United Arab Emirates	20	-	-	-	-	2
Kuwait	-	16	-	-	-	-
India	-	-	59	-	-	11
Hong Kong	2	-	16	-	-	-
Pakistan	-	-	-	16	-	-
Japan	-	-	1	8	6	12
Saudi Arabia	-	-	-	1	9	-

Source: National statistics

Table 24. Benzoin: exports from Thailand, and destinations, 1988-93 (tonnes)

	1988	1989	1990	1991	1992	1993
Total	17	6	11	14	3	8
Of which to:
Hong Kong	6	2	7	12	3	-
Singapore	5	2	-	-	-	8
Germany	4	2	3	1	-	-
France	2	-	1	1	-	-

Source: National statistics