Rutin is a yellow-coloured secondary plant substance from the class of bioflavonoids. Bioflavonoids are found in many natural plant foods. Rutin is the glycosidic compound of quercetin, supplemented by the disaccharide rutinose.
Like all flavonoids, rutin has valuable properties, which is why plants produce more of it under certain, more difficult conditions. They need the rutin as a colouring and protective substance, for example to ward off UV rays or microorganisms. Many plant foods contain rutin: figs, asparagus, peels of citrus fruits and apples, cherries, berries (blueberry, cranberry, goji berry), buckwheat as well as green and black tea. In addition to the Japanese cordwood, other plants and herbs such as white mulberry, red vine leaves, rue, St. John's wort and parsley are also very rich in rutin.
Rutin and vitamin C are also used, for example, as stabilisers in fruit juices to protect the vitamin C content from oxidation and thus preserve it.
