Total Anthocyanin Content, Total Phenolic Content, and Antioxidant Activity of Various Blueberry Cultivars Grown in Togane, Chiba Prefecture, Japan.

More than fifty cultivated varieties of blueberries are grown under the same processing conditions on the farm at Chiba Prefectural Agricultural College in Japan. The fruits from 51 blueberry cultivars, including 16 rabbiteye (RE) cultivars (Vaccinium ashei Reade) and 35 highbush (HB) cultivars (Vaccinium corybosum L.), were evaluated for total anthocyanin contents, phenolic contents, and their contribution to antioxidant activity among cultivars. Total anthocyanin contents varied from 0.74±0.21 ("Barkley") to 4.27±0.18 ("Suwannee") mg as cyanidin-3-glucoside (Cy-3-GC) equivalent/g fresh-weight (fw), with phenolic contents in the range of 0.77±0.14 ("Floridablue") to 3.69±0.89 ("Suwannee") mg of gallic acid equivalent (GAE)/g fw, which strongly correlated with antioxidant activities assessed using the DPPH and ORAC methods, respectively. Total anthocyanin and phenolic contents were both significantly higher (p<0.05) in RE blueberries than in HB blueberries. Furthermore, the total phenolic values were significantly higher for the RE family than for the HB family (p<0.01). In comparisons of two species, the major anthocyanidin identified were malvidin in RE blueberries and delphinidin in HB blueberries. This result suggests that some RE blueberries, especially "Suwannee," "Homebell" and "Climax," are suitable supply sources with high in vitro antioxidant capacity. This study would be helpful to the quality-oriented cultivation of blueberry.