Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 9, 2011
Publication Date: November 17, 2011
Citation: Wang, S.Y., Chen, H., Camp, M.J., Ehlenfeldt, M.K. 2011. Flavonoid constituents and their contribution to antioxidant activity in cultivars and hybrids of rabbiteye blueberry (Vaccinium ashei Reade). Food Chemistry. 132:855-864. Interpretive Summary: Consumption of fruits and vegetables rich in antioxidant compounds is associated with improved human health. One of our goals was to develop blueberries with enhanced antioxidant content. In order to select the best candidates for use as parents in the breeding program, we first characterized the variations in antioxidant content among 42 existing blueberry cultivars. We found that there were great variations in antioxidants among these materials. Several rabbiteye type blueberries had the highest antioxidants. Identification of these antioxidant-rich blueberry cultivars would enable their use in future blueberry breeding to develop new blueberry cultivars with higher antioxidants and antioxidant activities. This information is useful to consumers, blueberry growers, and the blueberry industry.
Technical Abstract: Fruit from forty-two blueberry (Vaccinium spp.) cultivars, including thirty-six rabbiteye cultivars (Vaccinium ashei Reade), three V. ashei hybrid derivatives, and three northern highbush (V. corymbosum L.) standards were evaluated for antioxidant capacity, individual flavonoid content, and the contribution of each identified phenolic compound to total antioxidant activity. Considerable variation was found in flavonoid content, antioxidant activity, and their contribution to total antioxidant activity among cultivars. Among 42 blueberry cultivars, the rabbiteye ‘Early May’ contained the highest amount of chlorogenic acid, myricetin 3-arabinoside, quercetin derivatives and delphinidin-, cyanidin-, petunidin-, and malvidin-basis anthocyanins. ‘Early May’ cultivar also had the highest antioxidant activity (88.2 'mol TE/g fw). ‘Owen’, ‘Bluegem’, ‘Clara’, Climax’, and ‘Centurion’ were among the other rabbiteye cultivars that also had high levels of flavonoids and antioxidant activities. In contrast, the pink-fruited V. ashei hybrid ‘Pink Lemonade’ had the lowest content of flavonoids and antioxidant activity. The mean flavonoid content and antioxidant activity of rabbiteye cultivars was higher than those among northern highbush and V. ashei hybrids. The antioxidant activity of V. ashei hybrid derivatives was derived mainly from chlorogenic acid, myrecetin, and quercetin which contributed 62.5% of total antioxidant activity, whereas anthocyanins (malvidin, petunidin, delphinidin and cyanidin) were the main contributors to the antioxidant activity of rabbiteye cultivars (76.2 %) and northern highbush standards (76.8%). Blueberry cultivars identified to have high phenolic content and high antioxidant activity could be used as parents for future blueberry breeding programs to develop new blueberry cultivars with higher antioxidant activity and further improve human health.