Cropwatch
6.
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.