Tannin
摘要
Several wood species, particularly in the southern hemisphere, contain tannins a polyphenol with a high molecular weight. Plants use them primarily to protect themselves against fungi and insects. Additionally, there is a possibility that herbivorous animals will not consume tannin-rich vegetables because of their astringent properties. Tannins have many industrial applications in many fields, including flotation separation, petroleum processing, farming, medicine industry, and leather manufacturing.