OPCs — Oligomeric proanthocyanidins

ligomeric proanthocyanidins (OPCs) are flavonoid compounds that provide the red-orange to blue-violet pigments present in many foods including fruits, vegetables, flowers and grains. These compounds are particularly concentrated in red grape seeds and skins and pine bark. They are also found in apples, cinnamon, cacao beans, blueberries, cranberries, açaí berries, grains such as sorghum, hibiscus, rosehips and green tea. In plants OPCs provide defence against pathogens, and it is the pathogens in the plants that trigger their production.