On Tanin: Properties, Applications and Sources
Tanin, this substance in the world, with its unique properties, is widely used in many places, and the source is also of great research value.

1. Properties of Tanin
Tanin has the property of convergence and feels astringent to the touch. When placed in water, it is soluble and makes the solution viscous. Its chemical structure contains many phenolic hydroxyl groups, which gives it the property of easy complexation with metal ions. When exposed to iron ions, it reacts quickly to form dark complexes, which can be seen in many scenes. And because of the existence of phenolic hydroxyl groups, it has strong antioxidant properties and can be slowly oxidized in air, causing the color to darken.

Second, the application of Tanin
In the field of medicine, the convergence of Tanin can help stop bleeding. The wound is applied with a substance containing Tanin, which can make local blood vessels constrict and stop bleeding. Its antioxidant properties can also scavenge free radicals in the body, delay cell aging, and prevent various diseases.
In the tanning industry, Tanin plays a key role. Its combination with collagen in leather makes leather flexible and resistant to corrosion. Tanin-tanned leather is durable and has good color.
In the food industry, Tanin can be used as a preservative. Due to its antioxidant properties, it can prolong the shelf life of food and preserve its flavor and nutrition. Tanin is also an important ingredient in tea and wine, giving it a unique taste and flavor, and increasing the pleasure of tasting.

Third, the source of Tanin
Plants are the main source of Tanin. Many trees, such as oak and chestnut, have bark rich in Tanin. In forests, oak bark is common, and a large amount of Tanin can be extracted after special treatment. The fruits and leaves of plants also contain Tanin. Pomegranate bark and tea leaves are all raw materials for obtaining Tanin. Some microorganisms can also produce Tanin during metabolism. Although the amount is small, it is also important in specific environments.