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Cropwatch 6.
Rosewood
Sustainability: Review of May P.H. & Barata E.S. “Rosewood Exploitation in the
Brazilian Amazon: Options for Sustainable Production”
Abstract: The authors report on ongoing work in the Brazilian Amazon to assess the current and prospective management of rosewood (Aniba rosaedora Ducke) populations threatened by a half-century of predatory extraction for the valuable essential oil linalool (sic) used widely in perfumery. The report synthesizes (sic) prior research on rosewood exploitation and markets and recent research to develop new essential oil products derived from rosewood leaves and stems. The study suggests alternative rosewood production systems, to guide investment in management and certification of sustainable rosewood oil supplies.
(N.B.
linalool is more correctly called an isolate, not
an essential oil –TB).
Critical Assessment of the May & Barata Paper
Copyright © Tony Burfield Oct 2004.
This is an undoubtedly much needed and informative paper and
adds to such data on the subject previously contributed by workers such as
Ohashi et al (1997) and Coppen (1996). The authors are Peter May who
works for the Dept. of Development, Agriculture & Society, Federal Rural
University of Rio de Janeiro and Lauro Barata who works for the Natural Products
Laboratory, State University of Campinas, São Paulo. Over 9-pages, the authors
explore the topics of Species Distribution & Distribution, Production Industry
in the Amazonas, the trade in Rosewood oil, Rosewood Extraction and the Threat
of Species Extinction and Rosewood Plantation Experience & Conclusions.
Unfortunately, as we will see below, the paper contains several factual
inconsistencies, which were not picked up under peer-review. Barata reveals an
involvement in analysis of rosewood plantation leaf oils and fine stems, and has
published two papers on this subject (Barata 2001; Barata & Discola 2002).
Species Description and
Distribution Section.
The authors state that the only source of rosewood oil (aka
Bois-de-Rose oil) is Brazil, but relate little of its former history. The Dutch
botanist Kostermans ascribed the name of the French Guiana tree Aniba duckei,
after the botanist Alfred Ducke had previously named the same unidentified
French Guiana tree “bois de rose” Aniba rosaedora, and named the
Brazilian variety A. rosaedora var. amazonica. The oil from the
French Guiana tree was introduced into European perfumery around 1866, but in
recent times it has been described as very scarce. I (TB) am familiar with
Cayenne Rosewood oil as a light yellow to yellow oil, with a sweet linalolic and
spicy character. It is sweeter and finer in odour than the Brazilian oil. It can
contain up to 90-97% laevo-linalol, but the range is more usually 85-95%;
correspondingly the optical rotation is in the range -10° and 17° - more
negative than Brazilian rosewood oil which is typically between -2° and + 5°
(Burfield 2004). The Essential oil Association in 1959 & 1963 had previously
defined Bois-de-Rose oil Brazilian as including both Cayenne Rosewood oil and
Peruvian Bois-de-Rose oil, and as possibly deriving from a number of species
including Aniba rosaedora var. amazonica Ducke, Aniba
parviflora Mez, Ocotea caudata Mez. etc. To this author’s certain
knowledge (TB) small lots of Rosewood oil from Ocotea caudata has been
sold into aromatherapy during 2003-4.
Returning to the paper on Brazilian Rosewood
oil, May & Barata say that the only port of export for Brazilian Rosewood oil is
that of Manaus, in contrast to statements in a press article (Osava 1998) which
maintain that illegal export of the oil occurs via “a variety of yet unknown
routes”. Previously Ohashi et al. (1997) had maintained that only 65% of
oil production is exported from Manaus, the rest being sold in São Paulo and Rio
to local branches of fragrance houses; May & Barata maintain that Firmenich is
the principle Brazilian buyer. May & Barata fail to mention the work of
environmentalists in Brazil who are actually against the extraction of Rosewood
oil (Osava 1997). The fragrance house Chanel has been
accused of contributing to the extinction of rosewood by use of rosewood oil in
the well-known perfume Chanel No 5, according to an NGO called "Robin Hood"
which had called for a worldwide boycott of the company (Osava 1997, Osava 1998).
The paper contains several typographical
errors, and errors of fact. For example the sentence on p258 “…there may have
been some tendency to substitute other Aniba species, leading to a change
in the refractive indices of the oil, which can contain 0.7% to 1.2% pure
linalool.” This is nonsense as Rosewood oil typically contains 84-93% racemic
linalool (Tony Burfield unpublished figures). It is likely that the “0.7% to
1.2%” wording actually refers to the yield of oil
from the tree as previously quoted by Ohashi et al. (1997) a fact
correctly established by the authors on p259.
The authors maintain (p258) that producers recognise two
plant sources and make little attempt to keep them separate, although
confusingly on p260 it is maintained that three types of aromatic wood are noted
by producers (the third type possessing little oil). They further maintain that
producers agree that the aroma of rosewood oil can vary from batch to batch,
hardly surprising considering the findings of tree to tree analytical quality
variations in the resultant distilled oil according to Ohashi et al.
(1997).
Rosewood Oil Production in
Amazonas
Interestingly, and in contrast to the Ohashi paper, the topic
of Brazilian deforestation does not appear per se in the text of the paper, nor
do other examples of the over-exploitation of rainforest commodity-bearing
species, putting them into a category of increased threat (see Margolis 2004 for
actual examples of this). Again, no history of concern contexting Rosewood
sustainability is presented – and, for example, Campbell de Araujo et al,
as long ago as 1972, expressed an opinion that propagation difficulties and
slow-growth of Aniba duckei meant that continuing supplies of Brazilian
Rosewood could not be assured ref: Cambell de Araujo et al. (1972). The authors
do, however, report on the status of rosewood as being included on the
endangered species list (IBAMA 1992) and, following discussions with producers,
new regulations were drawn up by the same organisation in 1998, requiring the
preparation and approval of sustainable management plans. Little is revealed in
the paper on any progress or success of these measures, although it is reported
on page 263 that “industrialists” “…plant 9 trees for each barrel of essential
oil produced, [and] have established other plantations.” The authors
subsequently admit, “this parameter is not generally adhered to by industry…”
but go on to refer to plantations established in Maués Amazonica. Without a
properly constructed fully independent audit of the bio-resources here, and
without spelling out who owns these exactly, it is impossible to make a
realistic opinion on the likely relevance, if any, of these initiatives.
May & Barata maintain that six licensed distilleries only,
now operate somewhat precariously within Manaus producing 50 tons of oil per
annum, but acknowledge that mobile distilleries exist, confirming the comments
made elsewhere (Osava M. 1998). Ohashi et al. (1997) commented that these
mobile stills are capable of producing 10 tons of oil per year. Conversely the
website of D. Cookson
http://www.cooksonco.com/ROSEWOOD.HTM who
maintain they obtained information via Brazilian exporters, reveal that 4
licensed distilleries operated in Manaus in 1999, producing 100 tons of oil (of
which 65 tons are exported). The figure of only 4 licensed distilleries around
Manaus, with a number of others operating illegally, has been confirmed by a
conservationist working in the region (personal communication, Chrissie Wildwood
2004).
Trade in Rosewood Oil
The demand for Rosewood oil fell due to the introduction of
cheap synthetic linalool (which the authors incorrectly state on page 259
occurred in the 1980’s, although further down the same page they suggest it was
the 1960’s - it was, in fact, the early 1960’s), and also due to the
availability of cheap Ho wood & leaf oils (from Cinnamomum camphora L.
var. linaloolifera and Cinnamomum camphora Sieb var. glavescens
Hayata etc). To put this into context, Lawrence (1995) states that the
production of Ho oil from China in 1995 was 800 tons/year. May & Barata do not
present an effective overview on end-usage applications of Rosewood oil in
contrast to synthetic linalool and Ho oils, as explained by their individual
characteristic odour qualities, and the differences in end-application
performance.
In reality, Rosewood oil is still used in fine fragrances
(male and female) but its price precludes its widespread use in cheaper
products. Synthetic linalol with its clear bell-like quality does not have the
spicy more complex piquancy that Rosewood oil possesses. Further the effects of
the two materials in use are quite different. For example Rosewood oil can
transform a lily-of-the-valley type perfume and bring it to life, whereas
synthetic linalool cannot, since its particular effects on the composition are
flatter and more one-dimensional.
Some of the following trace compounds are
present in rosewood oil as well as the major components, the linalool
enantiomers (TB)
and trace components such as para-methyl acetophenone
and tetrahydro para-methyl acetophenone seem to be important as modifiers
(TB 2000):
In contrast fractionated or double/triple rectified Ho oils
are nowadays available containing high purity laevo-linalool (99.6% +) of
high enantiomeric purity (to 99.7% laevo linalol). Demand for Ho oil
containing linalool of even higher enantiomeric purity (towards 100%) is high,
in order to adulterate lavender oil undetectably. The demand for high purity
acetylated Ho oil (to produce “natural” laevo-linalyl acetate) is also
similarly high for the same purposes.
Further, the authors do not take the following factors into
account:
1. Because of legislative requirements
affecting fragrances, the demand for natural
status linalool is often the
current driving factor, rather than a demand for linalool per se.
Thus the cheaper, but quite differently odoured, Ho oil has substituted for
rosewood oil because both are of natural status. The fact that Ho oils are
cheaper in bulk than some grades of linalol may also be a mitigating factor.
2. That the availability of natural materials is unreliable
because of climatic, political and other factors, and consequently prices can be
volatile. Although reliable information is scarce, Zhu (1994) has already warned
that supply of essential oils from various oil-bearing Cinnamomum species
in China is precarious due to over-exploitation. In apparent support of this
situation is the fact that Ho oil became in short supply in early 2003, and
continues to be scarce at the time of writing.
May & Barata present a breakdown of
destination information for Rosewood oil exports, the US being the principle
importer (47.5% of production for 2000-2003); other destinations include France,
Belgium and the UK. Ironically, at the time of writing, officials at IBAMA
- the
Brazilian export control authority – are on strike resulting in difficulties in
obtaining Rosewood oil from source.
Rosewood Extraction and the
Threat of Species Extinction.
Earlier, May & Barat stated that Rosewood harvesting &
distillation occur in the municipalities of Paratins, Rio Madeira, Presidente
Figueiredo, Manicoré and Maué. The authors produce a detailed account of the
amount of rosewood exploited (1700 trees per year – the IBAMA have accepted a
figure of 1000-2000) using the figure of 10Kg oil/ ton wood – 50 tons production
needing 5000 tons of wood/annum (i.e. yield is 1.0%). This is slightly at odds
with the statements on David Cookson’s website which state that 15 tons of wood
produce 180 Kg of oil (i.e. yield 1.2%). May & Barata conclude the occurrence of
rosewood trees in the wild is low (0.33 to 1.0 tree per hectare) and the
frequency of occurrence close to rivers (used to transport the sawn wood
downstream to distilleries) is negligible up to a distance of two kilometres
away. They repeat the opinions of the Agricultural & Forestry Sciences Faculty (FCAP)
that there are considerable populations of rosewood in deep forest areas distant
from streams.
The authors cite three divided opinions about the status of
rosewood: “at one extreme” are those of environmentalists and IBAMA who think
that over-exploitation has caused a demise; those of the distillers who maintain
the threat is exaggerated; and “in the middle ground” are the scientists of FCAP,
the National Industry for Amazonian Research – INAPA, and the Centre for
Agroforestry Research (EMBRAPA-CPAA). May & Barata refer to evidence of trees
still standing a four-hour walk from accessible streams, and evidence of natural
regeneration from field studies conducted by these bodies.
Slightly working against predicting outcomes from these
computations is the fact that the annual production figures for Rosewood oil
does not seem to be agreed with any degree of certainty – Mitja & Lescure (1996)
quoted Coppen’s 1995 figure saying production may be closer to 100-130 tons/year
rather than 50 tons/year quoted by the authors. With the reported problem of
illegal distillation units referred to above, this latter figure may well be
nearer the truth.
Rosewood Plantation
Experience.
The authors concede that
Rosewood oil is still 100% obtained from native stands, but describe a
plantation of 300 trees planted in 1973 at Curacá Una in the Tapajós river
valley in the state of Pará which was studied by Ohashi et al.
(1997). Importantly, the authors conclude on a chemotaxological basis that part
of this plantation consists of Aniba fragrans trees (this tree was
previously identified as the fragrant wooded tree Macacaporanga by Mors Walter &
Rizzini (1966) – TB). They also report on other experimental plots established
by the FCAP at Belém & in Benfica. It is concluded that due to the natural
variability of the species in terms of yield and aroma, the appropriate factors
for a viable commercial plantation operation could take decades to establish.
A small batch of oil, allegedly derived from
the distillation of plantation rosewood, gave the following analysis (TB 2004,
unpublished data):
Odour/appearance: Colourless oil with a strong, almost fruity rosy-citrus aspect dominating the usual woody-floral rosewood tonality, becoming more pleasant on airing. Not that reminiscent of normal rosewood oil, on first opening the container.
S.G. at 25°/25° C:
0.8795
Optical rotation at 20°C:
+ 0.57°;
Refractive index at 20° C:
1.4630
GC analysis: a-pinene
0.18%, b-pinene 0.83%, limonene ---1,8-cineole 0.40%, tr-ocimene 0.17%,
methyl heptenone ---, 3-octanol ---, methyl heptenol ---, linalol oxide A 0.17%,
linalol oxide B 0.18% --, citronellal 0.06%, a-p-dimethylstyrene ---, camphor
---, a-copaene 0.06%, linalol 84.74%, b-caryophyllene- --, terpinen-4-ol 0.20%,
benzaldehyde ---, a-terpineol 6.95%, nerol 0.12%, geraniol 1.93%, hotrienols ?
0.18%, b-caryophyllene oxide 0.13%, spathulenol ---, benzyl benzoate 0.32%.
It is unlikely that
perfumers used to the characteristic character of rosewood oil would be
impressed by this oil, and the relatively high a-terpineol content is perceived
as a decidedly negative quality factor (the transformation of linalool to
a-terpineol during distillation is known to occur, and may be able to be
controlled by more appropriate distillation conditions).
Potential for Extraction of
Essential Oil from Rosewood leaves.
This is an area of involvement for one of the authors as
previously noted, and the authors further concede that leaf oils are “somewhat
different” from wood oils [two of the three samples of rosewood leaf oil seen by
this author were judged to have no commercial value, being both crude and
oxidised]. The effect of shading on propagation of young trees is described in
some detail. Leaves are ready for coppicing in five years (seemingly a fall-back
from Ohashi et al. who had previously estimated 3 years). It remains to
be seen whether the oil will be attractive to essential oil buyers.
Conclusion.
In conclusion May & Barat present a case for a technological
search to solve the production of acceptable quality rosewood oil from
plantation grown and gathered leaves and stems, listing a series of suggested
steps. The omission of presenting an overall ecological impact assessment of
this monoculture project is quite glaring – “sustainable production” does not
just mean guaranteeing the continuance of an exportable commodity, rather it
means presenting a scheme which does not harm the environment. Failure to do
this in other plantation schemes has been previously reported by TB & CW in the
Cropwatch series (http://www.tonyburfield.co.uk/).
Low (2004) presented some wise words: “Many problems in
managing and protecting endangered species arise not from our ignorance of the
species’ ecology, but from human conflicts of interest”. Whilst the authors of
the paper noticeably distance themselves from entering into the sustainability
debate (calling the antagonists and protagonists “local actors”), their very
involvement in aspects of rosewood leaf oil production schemes biases their
paper in my opinion (TB), and I recommend that readers should seek opinions from
other sources on this subject, in the interests of balance.
References:
Barata L.E.S. (2001) “Rosewood leaf oils (Aniba rosaedora
Ducke): sustainable production in the Amazon.” IFEAT 2001 Int Conference, Buenos
Aires.
Barata & Discola KF (2002) “Scents of Amazon aromatic plants”
Presented at 33rd Int. Symposium on Essential Oils, Lisbon,
Portugal.
Burfield T. (2000) Natural Aromatic Materials – Odours and
Origins pub AIA Tampa Fl. (2000).
Burfield T. (2004) from the forthcoming 2nd edn of
Natural Aromatic Materials – Odours and Origins.
Cambell de Araujo V. et al “ (1972) Óleos
Essencias de Especies do Gêneor Aniba” An. Acad. Brasil. Cienc.,
44 (Suppl), 303-306 (1972); Acta
Amazonia 2(1), 1-4 (1972) through Lawrence B.M. (1984) “Progress in
Essential Oils” Perfumer & Flavourist Vol 9
(Oct/Nov 1984) p87-8.
Coppen J.J.W. (1996) Flavours & Fragrances
of Plant Origin FAO Rome 1996.
Lawrence B.M. (1995) “Progress in Essential Oils” Perfumer
& Flavourist Vol 20 July/August 1995 p30.
Low, Bobbi S. (2004) Endangered Species
Jan - Mar 2004 21(1)
p14.
Margolis M. (2004) “Jungle Economics: Environmentalists
though they could save the rain forest and make money at the same time. They
were wrong.” Newsweek International 16.02.2004
Mitja D. & Lescure J.-P. (1996) “Du bois pour da parfum : le
bois de rose doit-il disparaître?” In L. Emperaire ed. Le forêt en jeu
l’extrativisme en Amazonie Centrale UNESCO)-ORSTOM, Paris pp93-102.
through May & Barata (2004) above.
Mors Walter B. & Rizzini Carlos T. (1966) Useful Plants
of Brazil pub Holden-Day Inc 1966 p69
Ohashi S.T., Rosa J.A., Santana J.A., Green
C.L. (1997) “Brazilian Rosewood Oil: sustainable production and oil quality
management” Perfumer & Flavourist 22,
1-5.
Osava M. (1997) “Brazilian-Biodiversity: crackdown on
eco-pirates.” Inter Press Service English News Wire 15.08.1997
Osava M. (1998) “Brazil-Trade: Perfume Makers Accused of
Pirating Amazon Resources” Inter Press Service English News Wire
19.08.1998.
Zhu L., Ding D. & Lawrence B.M. (1994)
“The Cinnamomum species in China: Resources for the present and future”
Perf & Flav. 19, July/Aug 1994, 17-22.
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