To the large group of flavonoids (Vegetable dyes) counting Phenol compound (Polyphenol). It is found in plants such as various types of vegetables and fruits, in chocolate, in green tea, as well as in berry shells, stems and grape seeds, especially from red wines. For example, Merlot and Pinot Noir are high, while Syrah is low. Catechin acts as a repellent microorganisms plays an important role and is used, for example, in cases of infestation by real people mildew spontaneously formed as a defense reaction. Such substances are considered phytoalexins designated. Catechin contributes to the formation of tannins at or is part of it. It is one of the tannins and exercises one in wine astringent Effect on. But above all it is for the bitter Taste responsible. The substance has an antioxidant effect and therefore also has one health benefits, positive effect on increased blood lipids.