Catechu (dictionary definition) – any of several astringent substances obtained from various tropical plants, especially from the wood of two East Indian acacias, Acacia catechu and A. suma: used in medicine, dyeing, tanning, etc.
Catechu is an extract of several species of Acacia trees, palm trees and other plants such as Acacia catechu, Areca catechu (where the name comes from), Uncaria gambir, Butea frondosa, etc. It is extracted by boiling the wood in water and evaporating the resulting brew. It’s used in food and textile industries.
Catechu is used variously as a food additive, astringent, tannin, and dye. 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.
As an astringent catechu has been used since ancient times in Ayurvedic medicine as well as in breath-freshening spice mixtures. 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.
The leaves, shoots, and wood are used to make medicine. The two types of catechu, Black catechu and Pale catechu, contain slightly different chemicals, but they are used for the same purposes and at the same dose.
Varieties of catechu found in trade:
Black catechu, which is divided into Bombay and Bengali (kach).
The Bombay catechu is obtained from Acacia catechu (Senegalia catechu), which is cut down at the time when it is richest in juice. The core part is separated from all others, crushed, boiled with water, and the resulting juice is concentrated by evaporation.
The Bengal catechu is obtained from Areca catechu in the same way as the Bombay catechu, but the fruits are used, not the core of the tree.
Both varieties differ little from each other in their appearance (Bombay is darker and without veins) and go on sale in the form of large blocks of 2 to 3 pounds in weight, wrapped in leaves or packed in boxes.
Pale (yellow) catechu.
The Yellow catechu (also known as Cubic catechu, Gambier catechu, Gambir cachou) is obtained from the stems and leaves of the Uncaria gambir shrub, also by boiling it in water and thickening the resulting brew. In trade, it comes in the form of dirty yellow cubes and a size of about 1 inch (2.5 cm).
- 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.
- The leaves, shoots, and wood are used to make medicine. The two types of catechu, black catechu and pale catechu, contain slightly different chemicals, but they are used for the same purposes and at the same dose.
- Catechu is used for diarrhea, swelling of the nose and throat, dysentery, swelling of the colon (colitis), bleeding, indigestion, osteoarthritis, and cancer.
- People apply catechu directly to the skin for skin diseases, hemorrhoids, and traumatic injuries; to stop bleeding; and for dressing wounds.
- Catechu is included in mouthwashes and gargles used for gum disease (gingivitis), pain and swelling inside the mouth (stomatitis), sore throat, and mouth ulcers.
- In foods and beverages, catechu is used as a flavoring agent.
- In the food industry it is used for tinting drinks (vodka) and other products.
- In the textile industry it is used for dyeing fabrics.