Catechu

Catechu (/ˈkætᵻʃuː/ or /ˈkætᵻtʃuː/) 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 (Acacia catechu), by boiling the wood in water and evaporating the resulting brew. It is also known as cutch, black cutch, cachou, cashoo, khoyer, terra Japonica, or Japan earth, and also katha in Hindi, kaath in Marathi, khoyer in Assamese and Bengali, and kachu in Malay (hence the Latinized Acacia catechu chosen as the Linnaean taxonomy name of the type-species Acacia plant 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. It is also an important ingredient in South Asian cooking paan mixtures, such as ready-made paan masala and gutka.

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