Tannate

Tannates are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and other organic compounds including amino acids. They are a type of tannin, and the term "tannate" often implies a salt or ester of tannic acid.

In chemical terms, a tannate is the anionic form of a tannin when it is deprotonated. This deprotonation can occur due to the presence of a base or alkaline conditions. The resulting negatively charged tannate ion can then form salts with various cations, such as sodium tannate or potassium tannate. These salts are typically water-soluble.

The ability of tannates to bind proteins makes them useful in various applications, including:

• Tanning leather: Historically, tannates were used to convert raw animal hides into leather. The tannates cross-link with collagen fibers in the hide, making the leather more durable and resistant to decay.
• Medicine: Tannates have astringent properties and have been used in traditional medicine to treat conditions such as diarrhea and bleeding. Their ability to precipitate proteins can help to form a protective layer on irritated tissues.
• Clarification: Tannates can be used to clarify beverages, such as wine and beer, by precipitating proteins that can cause cloudiness.
• Mordanting: In dyeing, tannates can act as mordants, helping dyes to bind to fabrics more effectively.

Tannates are found naturally in a variety of plants, including bark, wood, leaves, and fruits. Common sources include oak bark, chestnut wood, and sumac leaves. The specific type and concentration of tannates can vary depending on the plant species and growing conditions.