Galangal 359
contained 1,8-ciniole, b-pinene and camphor as major constituents (Raina et al.,
2002).
Jirovetz et al. (2003) investigated the essential oils of the leaves, stems, rhizomes
and roots of A. galanga from southern India by GC-FID, GC-MS and olfactometry.
Mono- and sesquiterpenes and (E)-methyl cinnamate could be identified in all the
four samples and these are responsible for the characteristic odour and the reported
use in (folk) medicine as well as in food products. The essential oil of A. galanga leaf
is rich in 1,8-cineole (28.3%), camphor (15.6%), beta-pinene (5.0%), (E)-methyl
cinnamate (4.6%), bornyl acetate (4.3%) and guaiol (3.5%). The stem essential oil
contains 1,8-cineole (31.1%), camphor (11.0%), (E)-methyl cinnamate (7.4%), guaiol
(4.9%), bornyl acetate (3.6%), b-pinene (3.3%) and a-terpineol (3.3%). 1,8-cineole
(28.4%), a-fenchyl acetate (18.4%), camphor (7.7%), (E)-methyl cinnamate (4.2%)
and guaiol (3.3%) are the main constituents of the rhizome essential oil. The root
essential oil contains a-fenchyl acetate (40.9%), 1,8-cineole (9.4%), borneol (6.3%),
bornyl acetate (5.4%) and elemol (3.1%).
21.2 Production.......................................................................................
A. galanga is found in wild/semi-wild and cultivated states. The plant requires sunny
or moderately shady locations. Soil should be fertile, moist but not swampy. Sandy
or clayey soils rich in organic matter and with good drainage are preferred. Wild or
semi-wild types occur in old clearings, thickets and forests. In the tropics, galangal
occurs up to an altitude of 1200 m. Rhizomes (a rhizome piece with an aerial
shoot, known as slips) are used for propagation. Soil should be well tilled before
planting. Alternatively, holes, 35 cm ¥ 35 cm and 15–20 cm deep, are dug, filled with
manure mixed with soil, inorganic fertilizers and lime (for acid soils). One slip is
planted per hole, and covered with mulch. New shoots from pieces of galanga rhizome
emerge about one week after planting. About four weeks after planting 3–4
leaves develop. Rhizomes develop quickly and reach their best harvest quality in
three months after planting. If left too long they become too fibrous and large clumps
will hamper harvesting. Seeds rarely reach maturity. Often trenches are dug to drain
the field after rainfall, as rhizomes do not develop under waterlogged conditions.
Usually planted along the borders of gardens, in rows at distances of 0.5–1 m square.
Weeding and subsequent earthing up are carried out respectively 1–2 months
after planting.
Harvesting for use as spice is done usually three months after planting (during late
summer or early autumn) for market purposes. Whole plants are pulled out, shoots
cut off and rhizomes washed and cleaned. Rhizomes more than four months old turn
woody, fibrous and spongy and lose their value as spice. For essential oil extraction,
rhizomes are harvested when plants are about seven months old. However, for use in
ayurvedic and other traditional medicinal preparations rhizomes are harvested after
15 months, when the rhizomes become fibrous. No reliable data is available on the
yield (Scheffer and Jansen, 1999). Harvested rhizomes are washed, trimmed, dried
and marketed fresh or dried after packing (Scheffer and Jansen, 1999). Dried product
is ground before use. Ground rhizomes are not traded in bulk as they may be adulterated.
Essential oil is also a product.