Tannins are polyphenols found in plants, that is, naturally occurring chemicals. The main task of tannins is to bind and precipitate proteins. Numerous feeds consumed by animals and humans have a significant impact on the nutritional value of foodstuffs. Tannins are also part of antioxidants that act to prevent the wear of cells in the body. However, the amount of tannin contained in the plants can provide beneficial toxicity for the animals fed thereon, but can also lead to the death of the animals.

The effects of tannins on animals in terms of feed consumption, digestion and production efficiency vary according to many factors. The type and content of digested grains, as well as the characteristics of the digestive system of animals, feeding habits and body sizes are important at this point. Tannins complex with many molecules such as protein, polysaccharide, mineral and nucleic acid.

Tannin is also known as tannic acid. Rather, it is obtained from plants such as broad beans, rapeseed, tea, sorghum, thuja oak and acorn. Tannins are usually found in the roots, stems, leaves and fruits of plants. Tannins are what are used to clarify excess wine and beer. It is also used in the leather and dyeing sectors, to prevent the formation of deposits on the walls of steam boilers and in pharmaceutical composition to prevent vasoconstriction.

There are tannic acid in tea. Tannic acid is drawn into the water when the tea is extracted with hot water, ie brewed. The solution is then evaporated to give tannin as a solid.

Tannin content analyzes are also performed in authorized laboratories within the scope of chemical food analyzes. These analyzes comply with the standards and test methods issued by national and international organizations. The standards used in tannin analysis are as follows:

• TS ISO 9648 Sorgun - Determination of tannin content

This standard specifies a general method for the determination of tannin content in sorghe grains.