36E-70

D. PILAND, L. R. Howard, and J. R. Clark. Dept. of Food Science, Univ. of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704

Blueberries contain large amounts of flavonoids, which have been shown to provide numerous health benefits associated with their antioxidant properties. However, there is little information available on the effect of harvest date on antioxidant compounds and berry weight. Our objective was to quantify and compare phenolic compounds and antioxidant capacity in five blueberry genotypes harvested on several dates. Mature fruit from three advanced breeding selections and two commercial varieties of blueberries were analyzed for total phenolics (TP), Total Anthocyanins (TA), Oxygen Radical Absorbance Capacity (ORAC_FL) and average berry weight. The advanced breeding selections US 497, US 720 and US 729 exhibited a decrease in mean berry weight at later harvest dates with no concomitant changes in TP, TA or ORAC_FL values. Average berry weights for Ozarkblue and Bluecrop varieties increased from first to mid-harvest dates and then decreased on subsequent harvest dates. Both varieties contained the highest TA levels at peak berry weight. The three advanced breeding selections showed positive correlations between TA and ORAC_FL values ranging from R²=0.41 in US 729, R²=0.61 for US 497 and R²=0.96 for US 720. Bluecrop showed positive correlations between berry weight and TA (R²=0.61) and berry weight and TP (R²=0.63), while Ozarkblue showed a positive correlation between berry weight and TP (R²=0.41). Our results indicate that the effect of harvest date on phenolic content and ORAC_FL of blueberries is genotype dependent. The three advanced breeding selections maintained similar phenolic levels irregardless of harvest date or variation in average berry weight, while the two commercial varieties contained the highest anthocyanin levels at peak berry weight. This information can be of benefit to food scientists and fruit breeders who are interested in the relationship between harvest date and antioxidant components present in blueberries.

Session 36E, Fruit & Vegetable Products: General
8:30 AM - 12:00 PM, Monday AM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana