18E-2

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

Consumption of phytochemical-rich fruits and vegetables has been implicated in reduced risks of numerous chronic diseases. Quantification of the phytochemicals and antioxidant capacity of fruits and vegetables is important to substantiate potential health benefits. Although the polyphenolic composition and antioxidant (AOX) capacity of mature blackberries has been reported, the changes that occur during fruit maturation have not been thoroughly investigated. The objective of this study was to determine how fruit maturation affected the polyphenolic composition and peroxyl and superoxide scavenging capacities of Apache and Chickasaw blackberries. Each cultivar was evaluated at five stages: green, red, mottled, black, and overripe. Ellagitannins, flavonols, and anthocyanins were separated by reverse-phase HPLC at 254, 360, and 510 nm, respective-ly. AOX capacities were determined by the ORAC and PCL assays, and Total Phenolics (TP) were measured using the Folin-Ciocalteu assay. In both cultivars, ellagitannins decreased, while anthocyanins increased as fruit ripened. Flavonols were highest in immature fruit and generally declined with ripening. TP showed a similar trend as ellagitannins (R²=0.90), but not with anthocyanins and flavonols (R²=-0.22 and 0.47, respectively). PCL and ORAC values decreased substan-tially from the green to mottled stage. PCL values increased with further ripening in both cultivars, while ORAC values only increased in overripe fruit of Apache. ORAC values correlated well with ellagitannins and TP (R²=0.90 and 0.83, respectively), but not with anthocyanins or flavonols (R²=-0.22 and 0.47). PCL values correlated well with ellagitannins and flavo-nols (R²=0.66 and 0.76, respectively), but not with TP and anthocyanins (R²=0.59 and -0.11, respectively). Our results indicate that immature black-berry fruit are a rich source of ellagitannins that exhi-bit potent peroxyl and superoxide scavenging capacities. The immature fruit culled from processing operations could be utilized as a natural source of antioxidants or nutraceutical ingredient.

Session 18E, Nutraceutical & Functional Foods: General I
2:00 PM - 5:30 PM, Sunday PM Room Hall I-2

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