Anthocyanins1. OverviewAnthocyanins are a type of flavonoid that acts as an effective antioxidant in the human body. Found naturally in various foods, anthocyanins are a water-soluble colored pigment that gives many fruits and vegetables bright red, blue and purple colors. Depending on pH and the presence of chelating metal ions, anthocyanins appear different colors, due to their conjugated bonds in their structures that absorb light at approximately 500 nm. Anthocyanins are anthocyanidin glycosides, attaching glucose, galactose, rhamnose, xylose or arabinose to an aglycone core. There are six common anthocyanidin backbones: cyanidin, delphinidin, pelarogonidin, malvidin, petunidin, and peonidin. The anthocyanidin backbone is typically conjugated to the sugar components via the C3 hydroxyl group in the C ring. According to recent literature, more than 550 different anthocyanins have been reported, varying in the basic anthocyanidin backbone and in the manner in which they are attached to the glycosides. .2. Food SourcesAnthocyanins are found in all tissues of higher plants and are present in various fruits and vegetables, particularly in Vaccinium species, such as bilberry, cranberry, and bilberry. Other food sources include: cherries, black currants, grapes, plums, red peaches, pomegranates, bananas, eggplant, asparagus, red cabbage, black beans and black rice. In the United States, the daily intake of anthocyanins has been estimated to be 180 to 215 mg/day, which is approximately 9 times higher than that of other dietary flavonoids.3. Metabolisms and physiology3.1 Anthocyanin metabolismThe mechanisms associated with the absorption, transport and excretion of anthocyanins are still largely unexplored.The mechanisms involved in absorption and transp...... middle of paper.. ....during the human body due to its high bioactivity. Another concern is the susceptibility of anthocyanins to be oxidized and degraded, which limits the shelf life of its products. Finally, it is difficult to follow the metabolic progression of anthocyanins after ingestion, because they will be rapidly degraded into various metabolic products. In the United States, the daily intake of anthocyanins has been estimated to be between 180 and 215 mg/day. As a natural pigment in fruits and vegetables, anthocyanins are safe antioxidants. A wide range of research has demonstrated the beneficial effect of anthocyanins in promoting antioxidant status, improving vision, protecting cardiovascular health and cognitive function, and preventing cancer, obesity, and diabetes. Although more human studies are needed to confirm the health benefits of anthocyanins, the currently available data is very encouraging..