Catechu

Catechu (/ˈkætɪʃuː/ or /ˈkætɪtʃuː/)[1] is an extract of acacia trees used variously as a food additive, astringent, tannin, and dye.

[2] The Malay name kachu is the basis of the Latinized[3] catechu chosen as the Linnaean taxonomy name of the plant species which provides the extract.

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.

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.

[7] The catechu extract gave its name to the catechin and catechol chemical families first derived from it.