A review of dipterocarps - Center for International Forestry Research

Non-Timber Forest Products from Dipterocarps
water, does not volatilise at room temperature, and
possesses a characteristic pungent odour and burning
taste. It is used in medicine, perfumery and organic
syntheses. Borneo camphor is almost pure d-borneol
(C 10 H 17 OH, M.P. 209 o C) and is highly prized in Indian
medicine. Chinese and Japanese also attribute a higher
medicinal value to it than the essential oil from the wood
of Camphora officinalis. It is converted into ordinary
camphor by heating with boiling nitric acid. (Balfour
1985, WOI 1989a). Dryobalanops aromatica is no
longer a major source of camphor now that
Cinnamomum camphora is used in the chemical industry
and camphor can be synthesised more cheaply from
pinene.
Butter Fat
Another major dipterocarp NTFP in Borneo is butter fat.
Shorea species (the Pinanga type) produce illipe nuts
which are called engkabang and tengkawang in Malaysia
and Indonesia, respectively. The nuts are generally
collected in the wild but some experimental plantations
of S. macrophylla, S. stenoptera, S. mecistopteryx, S.
aptera and other related species exist in Sarawak and
Kalimantan (Tantra 1979). The fruiting is somewhat
aperiodic but at about four year intervals the forests fruit
heavily. The natives of Borneo extract oil from the nuts
for use as cooking oil (Anderson 1975). The kernels are
exported to Europe, Japan and West Malaysia. The illipe
fat extracted from the kernel is used in the confectionery
industry, especially in the manufacture of chocolate. The
illipe fat has a high melting point, and when blended with
cocoa butter remains solid at room temperatures.
Likewise, illipe fat is added to cosmetics such as lipstick.
The illipe nuts have a high value with prices from US
$2300-2700 per tonne in the 1980s (Anon. 1985b), and
during peak fruiting years exports from Borneo can reach
50 000 tonnes (Wong Soon 1988).
Shorea robusta (sal) from the Indian region is
another important source of butter fat. The kernels,
constituting 72% of the nut weight contain 14-20% of
fatty oil known as sal-butter. Sal seed oil has assumed
great importance for use as a cooking medium, industrial
oil, illuminant, lubricant and as a substitute for cocoabutter.
It is also suitable for soap making after blending
with other softer oils. The sal fat is obtained by boiling
the husk seeds in twice the volume of water and skimming
off the oil which solidifies to a buttery consistency in
cold weather. In India sal fruits must be collected before
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the onset of the monsoon when it becomes difficult to
dry and decorticate them. The dried fruits can be
decorticated by hand or with mechanised decorticators
after manually dewinging them. The fruits are spread on
a hard surface to a thickness of about 10 cm and beaten
with sticks to dewing them. The oil is also obtained by
solvent extraction of seeds by flaking procedure. The
particle size of the kernel is reduced to 7-10 mesh by
using fluted rolls and cooked at 2.25 kg cm -2 steam
pressure with limited open steam injection so as to adjust
the meal moisture content in the flaking rolls to about
15%. A steam jacketed flight screw kettle is most suitable
for cooking the meal. The flakes are tempered to a
thickness of 0.24 - 0.3 mm with a moisture content of
8%. They do not show any sign of disintegration on
solvent impact due to the kernels' high starch content.
Studies show that, even with proper conditioning of the
kernels, it is not possible to obtain a good yield of fat by
expeller. The fat is refined by a conventional method of
alkali refining. However, the small recoverable fat
content of 14% is disadvantageous because the fat
contains various kinds of pigments even after refining.
The glycerides of the kernel fat are a rich source of stearic
and oleic acid (44.2 and 44.9%) in addition to palmatic
(4.6%) and arachidic acid (6.3%).
The kernels of Vateria indica from India yield about
22% fat by solvent extraction. This is known as piney
tallow, malabar tallow or dhupa tallow. It is extracted by
boiling the powdered kernels in water, then allowing the
extract to cool and skimming off the floating fat. The fat
has a slight, pleasant odour and is greenish yellow at first
but rapidly lightens in the air. It consists of glycerides
of solid acids (53%) and liquid acids. (Puntembaker and
Krishna 1932). The tallow is edible after refining, but is
not in common use. It is used in confectionery and as an
adulterant of ghee, in candle and soap manufacture, and
for sizing cotton yarn instead of animal tallow. It is also
used as a local application for rheumatism.
Tannin
The leaves and bark of several dipterocarps are a source
of tannin. The bark of Hopea parviflora from India is a
good tanning material for heavy leather, particularly when
used with other tanning materials, for example myrobalan
bark in a 2:1 ratio which gives a good quality, reddish
brown leather resistant to mould. The bark contains 14-
28% tannins and the solid extract, an astringent with slow
diffusion speed, 70% tannins (Anon 1985a). The tannin