76C-10 |
Antioxidant capacity and phenolic content of blueberry cultivars and breeding selections as affected by growing season |
C. R. BROWNMILLER1, L. R. Howard, and J. R. Clark. (1) Food Science Department, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR 72704 Blueberries contain high levels of flavonoids, which exhibit potent antioxidant activity as well as numerous other biological and pharmacological properties. Although the effects of genetics and postharvest storage conditions on phenolic content and antioxidant capacity of blueberries are well documented, no information is available concerning the effect of different growing seasons on changes in phenolics and antioxidant capacity of blueberry cultivars. The objective of this research was to determine the effect of growing seasons on phenolic content and oxygen radical absorbing capacity (ORAC) in blueberry cultivars and breeding selections. Thirteen advanced selections and five commercial cultivars of blueberries grown at the same location were harvested at peak ripeness in 2000 and 2001. Fruit were analyzed for total phenolics, total anthocyanins, tartaric esters and flavonols using spectrophotometric assays, ORAC using a microplate assay and berry weight. Phenolic content and ORAC of blueberries was affected more by cultivar and the interaction between cultivar and growing season then growing season, but several cultivars varied greatly in their ability to synthesize phenolics over the two growing seasons. Blueberry fruit varied the greatest in total anthocyanin content over the two growing seasons indicating that synthesis of anthocyanins was affected most by differences in environmental growing conditions. Three small fruited selections, US-497, US-729, and A-98 had exceptionally high ORAC, total phenolic, total anthocyanin, tartaric ester and flavonol contents over both growing seasons. Total phenolics, total anthocyanins, tartaric esters and flavonols correlated positively with ORAC over both growing seasons, while fruit weight correlated inversely with ORAC. Our results indicate that plant breeders can select for increased phenolic content in blueberry cultivars to increase antioxidant capacity, but blueberry cultivars should be analyzed over several growing seasons in order to identify phenolic and antioxidant rich germplasm.
Session 76C, Fruit & Vegetable Product: Fresh Fruits and Vegetables
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