Peru and Tolu balsams (FAO, NWFP 6)
- See the main page Baumes (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
- 1 DESCRIPTION AND USES
- 2 WORLD SUPPLY AND DEMAND TRENDS
- 3 PLANT SOURCES
- 4 COLLECTION/PRIMARY PROCESSING
- 5 VALUE-ADDED PROCESSING
- 6 PRODUCTS OTHER THAN RESIN
- 7 DEVELOPMENTAL POTENTIAL
- 8 SELECTED BIBLIOGRAPHY
DESCRIPTION AND USES
Both balsams are oleoresin exudates obtained from trees of the genus Myroxylon which are native to Central America and northern parts of South America. Peru balsam is a dark brown, very viscous liquid, with a typically "balsamic" odour, somewhat resembling vanilla. Tolu balsam is a brownish yellow, plastic solid when fresh, but becomes harder, and eventually brittle, on exposure to air.
Peru balsam is sometimes used in its natural form in perfumery, where it acts as a fixative, but its dark colour is a disadvantage, as is the insolubility of some of its constituents in other perfume materials. The oil or resin-free preparations of the balsam are therefore more widely used in perfumery than the balsam itself. The odour tenacity of the oil is very great and it is used as a fixative in perfumes.
Peru balsam contains a mixture of benzyl benzoate and benzyl cinnamate and these confer a mild antiseptic action on the balsam; it is used in some pharmaceutical preparations for treating skin disorders.
Tolu balsam has a similar mixture of benzoic and cinnamic acid esters to Peru balsam and has fragrance and pharmaceutical uses. The balsam itself is rarely used, but the essential oil is used in perfumery and a few flavour applications, while solvent extracts are employed as fixatives in perfumery. Tolu balsam is used as an expectorant and as a flavouring compound in cough mixtures and other pharmaceutical preparations, often in combination with other balsams, although, today, many Tolu syrups are synthetic mixtures rather than ones which contain the genuine balsam.
WORLD SUPPLY AND DEMAND TRENDS
Peru and Tolu balsams are not separately identified in the trade statistics of gums and resins for most countries and import data are therefore not readily available. In the 1940s, exports of Peru balsam from El Salvador were around 100 tonnes annually and the United States was the major importer. In 1971 it was estimated that the United Kingdom perfumery industry consumed up to 50 tonnes/year of Peru balsam.
Exports of Tolu balsam were around 80 tonnes/year in the 1940s. Recent import data are available for India (Table 25) and indicate that she normally imports about 10 tonnes/year. Imports were exceptionally high in 1992/93 (30 tonnes) but it is not certain whether the imports from Southeast Asia (which totalled 21 tonnes in 1992/93 and amounted to up to 5 tonnes in previous years) are of genuine Tolu balsam, despite their classification as such.
In the last decade or so, the use of genuine tolu balsam in pharmaceutical preparations has declined, and so-called synthetic Tolu solutions and syrups are manufactured using commercially available benzoic and cinnamic acids and their esters.
Despite its name, El Salvador is the chief source of Peru balsam. Colombia is the main source of Tolu balsam, although Venezuela has been a minor supplier in the past. No production data are available for either of the two products.
European sources of Tolu balsam given in Table 25 represent re-exports of South American material.
Quality and prices
In terms of chemical composition, the quality of the two balsams is very variable. However, balsams (or their oils) which are offered for sale are often compounded or blended materials or, in the case of Tolu balsam, totally synthetic, and analysis of them will not necessarily be a reflection of the composition of the genuine article.
The British Pharmacopoeia defines Peru balsam as containing 45-70% of esters, mainly benzyl benzoate and benzyl cinnamate; it should also have a saponification value of 230-255.
Tolu balsam does not appear in the British Pharmacopoeia (only syrups and solutions). The current (mid-1995) New York listed price of Tolu balsam is equivalent to US$ 15/kg; a London list price is equivalent to about US$ 11.75/kg. Peru balsam is listed at US$ 13.50/kg in London.
- Myroxylon balsamum L. Harms var. pereirae (Royale) Harms (syn. Myroxylon pereirae (Royale) Klotzsch) - Peru balsam
- Myroxylon balsamum L. Harms - Tolu balsam
Description and distribution
Myroxylon balsamum var. pereirae is a large tree of Central America, although almost all Peru balsam of commerce originates in El Salvador.
Myroxylon balsamum is a tall tree of the forests of northern South America, particularly Colombia and Venezuela; it is also found in Cuba. The name Tolu comes from the province of Tolu in Colombia, where Myroxylon balsamum was particularly common along the Magdalena and Cauca rivers.
Methods described in the 1950s and late 1960s for the collection of Peru balsam involve firstly the removal of bark from the tree; the balsam is then extracted from both the bark and the exposed trunk in a separate operation.
Rectangular strips of bark are removed from trees which have previously been beaten or scorched by fire and left for 6-8 days (during which time the bark softens). Intermediate strips of bark are left sound to avoid permanent damage to the tree. The removed bark is then crushed and pressed in the presence of hot water which softens the balsam and facilitates its extraction. The exposed trunk wood is covered with rags which absorb the balsam and these are also treated with hot water. In both cases (bark and rags), the balsam settles to the bottom of the containing vessels and is removed after decanting the water. Up to 18 "tappings" can be made each year at approximately two-week intervals.
Older methods of primary processing involved heating the balsam over an open fire to remove residual moisture and straining it while still hot to remove extraneous matter.
The traditional method of collecting the balsam is to make V-shaped cuts into the bark of the tree which just reach the phloem but not the cambium. Each cut is about 5 mm thick and the V has a maximum width of 7-10 cm. Two more V-cuts, with a more open V than the first, are made above the original cut, and the resin which is caused to flow runs down the trunk into a suitable receiver fixed to the tree. Several receivers may be in place at any one time. Fresh cuts are made at intervals throughout the year. In the second year, part of the trunk above the first area is worked. This may be repeated for a third year, after which time the tree is rested for three years before further tapping. Alternatively, the tree is tapped in alternate years.
Crude processing is carried out in a manner similar to Peru balsam.
Average yields of Peru balsam have been reported to be about 2.5-3.5 kg/tree/year. Trees of 25-30 years of age may be tapped but productivity increases as the trees get older, reaching a maximum at about 60 years. Highest yields are obtained during the hot, dry periods of the year.
WILLIAMS (1974) reports that in a year (1968) when yields were generally regarded as low by the tappers, the average yield of Tolu balsam at one collection site was 1.7 kg/tree.
Steam distillation of Peru balsam gives a very low yield of genuine essential oil, and most oil which is used is obtained either by direct distillation under vacuum or by extraction with a suitable solvent. The true, total oil is semi-solid at ambient temperature, and commercial oils which are viscous liquids are therefore likely to contain diluents.
Tolu balsam oil can be produced in low yields by steam or direct distillation of the balsam. Tolu "absolutes" and "resinoids" are produced by extraction with organic solvents.
PRODUCTS OTHER THAN RESIN
No other products of commercial value are obtained from the trees.
Myroxylon species are amenable to cultivation and WILLIAMS (1974) reports a Myroxylon balsamum plantation 31/2 years old in which trees planted under shade were less than 1 m in height, but those in the open reached 3-5 m and 10 cm in diameter. The market for both types of balsam is relatively small, although not insignificant, and the economics of production are not known, but if land is available to set aside for such planting - perhaps taking advantage of the leguminous nature of the trees by planting with shorter term crops in an agroforestry context - then the trees could provide a useful cash income in later years.
Apart from the pressing need for up-to-date market information, several areas of research are immediately identifiable:
- Germplasm screening. WILLIAMS (1974) reported wide tree-to-tree variation in yields of Tolu balsam. Natural populations of both Myroxylon species need to be screened to identify high yielding provenances and/or individual trees, as well as trees with good growth characteristics and other desirable features.
- Growing trials. Selected planting stock should be raised and tested under a number of different agroforestry regimes.
- Tapping trials. The age at which tapping can commence, improved methodologies for collecting the oleoresin, and the best regime under which tapping can be sustained so as to maximize economic returns all need to be investigated.
- 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].
- 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 (1993) Peru Balsam. pp 495-496. In British Pharmacopoeia, Vol. 1. London: Her Majesty's Stationery Office.
- GUENTHER, E. (1952) Oil of balsam Peru. pp 212-220. In The Essential Oils, Vol. 5. New York: Van Nostrand Co.
- GUENTHER, E. (1952) Oil of balsam Tolu. pp 220-225. In The Essential Oils, Vol. 5. New York: Van Nostrand Co.
- HARKISS, K.J. and LINLEY, P.A. (1979) A comparative study of the acid and ester content of Tolu balsam. Planta Medica, 35, 61-65.
- WALKER, G.T. (1968) Balsam of Peru. Perfumery and Essential Oil Record, 59, 705-707.
- WILLIAMS, J. (1974) [Preliminary study of the production of resin from Tolu balsam] (in Spanish). Bosques de Colombia, (July), 31-55.
|Of which from:|
Source: National statistics
- Year runs April-March