Anthocyanin Content and Antioxidant Activity of Different Varieties Blueberries
Fresh fruits and vegetables are rich sources of nutrients and phytochemicals for health. Thus, consumer has increased the demand for them, particularly blueberries. Two varieties of cultivated blueberries and a wild blueberry (Vaccinium uliginosumL.) were selected in order to determine their antioxidant activity as related to their anthocyanins. Anthocyanin content of different varieties of blueberries was determined by pH differential method. Anthocyanins from different varieties blueberries were assayed for their antioxidant properties in vitro systems, including inhibiting activity on lipid peroxidation, scavenging activity on hydroxyl radical, superoxide anion radical and DPPH radical. The results showed that anthocyanin content of wild blueberry was the highest and anthocyanin content of Northland blueberry was the lowest among different varieties blueberries. Blueberries anthocyanins were effective antioxidants, and there was a dose-dependent relationship between anthocyanins content and antioxidant activity. The overall antioxidant capacity ranked on the order of Blomidon blueberry>wild blueberry>Northland blueberry. The result also showed that antioxidant property was not only correlated with anthocyanins content but also related to their composition and structure. Blueberries anthocyanins was a rich source of natural antioxidant and potential used as a food additive.