Correlation of oxygen radical absorbance capacity (ORAC) value with anthocyanin and phenolic content of peaches
W. McGlynn and B.D. McCraw
Book of Abstracts, 2004 IFT (Institute of Food Technologists) Annual Meeting and Food Expo, 13-16 July 2004, Las Vegas, Nevada, USA. 321 pages.
2004
บทคัดย่อ
Correlation of oxygen radical absorbance capacity (ORAC) value with anthocyanin and phenolic content of peachesThe public increasingly makes food purchasing decisions based on a food’s perceived health promoting characteristics.Small-scale fruit growers and processors may benefit from growing and marketing varieties with nutraceutical benefits, such as high antioxidant activity.The goal of this study was to measure oxygen radical absorbance capacity (ORAC) values in peaches with varying flesh colors and to correlate ORAC values with anthocyanin and total soluble phenoliccontents.Ripe fruit samples of eight varieties of peaches were collected from the Oklahoma State Univ. Fruit Experiment Station in Perkins, OK.Samples were homogenized and extracted using a methanol: acetone: water: acetic acid (40:40:20:0.1) solvent.Total anthocyaninswere quantified using the pH differential method.Antioxidant activity was measured using the ORAC assay as modified for a Perkin/ Elmer HT7000 microplatereader.Significant differences were seen in ORAC values, anthocyanin content, and total soluble phenolics among the peach varieties evaluated.ORAC values ranged from 3.90 to 5.02 mM Trolox equivalents per gram of fresh peach.The red fleshed variety tested had the highest average ORAC value observed.Yellow fleshed varieties were next while white fleshed varieties had the lowest measured average ORAC values.More variability was seen in anthocyanincontent that in ORAC value or total soluble phenoliccontent.Overall, a good correlation (coefficient=0.845) was seen between ORAC value and phenolic content.However, no significant overall correlation was seen between ORAC values and anthocyanin content.These results show that antioxidant activity of peach varieties varies and the ORAC value correlates with total soluble phenolic content.This opens possibilities for screening peach varieties for antioxidant activity by measuring phenoliccontent.This may allow growers and processors to more readily include antioxidant activity as a criterion when judging peach varieties.