Tanin is a naturally occurring compound found in various plants, particularly in the bark, leaves, and fruits. It belongs to a class of polyphenols and is known for its astringent properties, which can cause tissues to contract. Tanin is commonly found in foods and beverages like tea, wine, and chocolate, contributing to their flavor and health benefits. In addition to its culinary uses, tanin has applications in traditional medicine and the tanning industry. It is used for its antimicrobial properties and can help preserve animal hides. Tanin's ability to bind proteins makes it valuable in various industrial processes, including the production of inks and dyes.