Catechu

Catechu is an extract of acacia trees used variously as a food additive, astringent, tannin, and dye. It is derived from several species, but primarily Acacia catechu (also known as Senegalia catechu). The extract is rich in tannins, which give it its astringent properties.

Production and Composition

Catechu is typically produced by boiling wood chips of acacia species in water and evaporating the resulting brew, leaving a residue that hardens into a brittle substance. The primary active compounds in catechu are catechins (related to tannins), including catechin, epicatechin, and their derivatives. The exact composition varies depending on the acacia species used and the manufacturing process.

Uses

• Dyeing: Historically, catechu has been used as a brown dye for textiles, leather, and other materials. It can produce a range of shades depending on the mordant used.
• Tanning: The high tannin content makes catechu suitable for tanning leather. It helps to convert animal hides into durable leather.
• Traditional Medicine: Catechu has been used in various traditional medicine systems for its astringent and antiseptic properties. It has been used to treat conditions such as diarrhea, bleeding, and skin problems.
• Food Additive: In some regions, catechu is used as a food additive, often in betel quid chewing, where it contributes to the reddish stain and astringent flavor. It's also used in some traditional candies and confectionery.
• Other Applications: Catechu may also be found in some types of adhesives and inks.

Varieties

The term "catechu" can refer to different types of extracts depending on the source and processing methods. These may include:

• Black Catechu: Typically derived from Acacia catechu and has a darker color and more astringent taste.
• Gambier Catechu: Extracted from Uncaria gambir, a climbing shrub native to Southeast Asia. It has similar applications to black catechu.