From en.wikipedia.org:
[Extract of acacia trees] [the region in India]
<SPAN LANG="EN" DIR="RTL">CATECHU</SPAN> ([ˈ] or [ˈ])[1] is an extract of
acacia trees used variously as a food additive, astringent, tannin, and dye.
It is extracted from several species of Acacia, but especially _Senegalia
catechu_ (previously called _Acacia catechu_), by boiling the wood in water
and evaporating the resulting brew.[2] The Malay name [ms] is the basis of the
Latinized[3] _catechu_ chosen as the Linnaean taxonomy name of the plant
species which provides the extract.
** Uses
As an astringent it has been used since ancient times in Ayurvedic medicine as
well as in breath-freshening spice mixtures—for example in France and Italy it
is used in some licorice pastilles. It is also an important ingredient in
South Asian cooking paan mixtures, such as ready-made paan masala and gutka.
The catechu mixture is high in natural vegetable tannins (which accounts for
its astringent effect), and may be used for the tanning of animal hides.
Early research by Humphry Davy in the early 19th century first demonstrated
the use of catechu in tanning over more expensive and traditional oak
extracts.
Under the name _cutch_, it is a brown dye used for tanning and dyeing and for
preserving fishing nets and sails. Cutch will dye wool, silk, and cotton a
yellowish-brown. Cutch gives gray-browns with an iron mordant and
olive-browns with a copper mordant.[4]
Black catechu has recently also been used by Blavod Drinks Ltd. to dye their
vodka black.[5]
White cutch, also known as gambier, gambeer, or gambir, which is extracted
from _Uncaria gambir_[6] has the same uses. Palm-catechu is extracted from
the seeds of _Areca catechu_.[7]
** Derivative chemicals
The catechu extract gave its name to the catechin and catechol chemical
families first derived from it. Its historic name is "Japanese Earth" or
"Japanese Dirt", which is responsible for naming "Japanic acid".
** See also
- Arid Forest Research Institute
** References
[reflist]
** External links
[Catechu]
- An OCR'd version of the US Dispensatory by Remington and Wood, 1918. (see http://www.henriettesherbal.com/eclectic/usdisp/uncaria-gamb.html)
[dyeing]
Category:Plant dyes Category:Spices Category:Tannins