TOTAL PHENOLIC, CAROTENOID, AND ANTHOCYANIN CONTENT AND ANTIOXIDANT ACTIVITY OF PEACH AND PLUM GENOTYPES

Abstract

Fruits contain a range of phenolics and carotenoids which have been implicated in improving human health. The objective of this study was to characterize the phytochemicals and antioxidant activity (AOA) exhibited in peaches and plums and to determine if any associations existed between these phytochemicals and AOA. Twenty-two peach varieties and fifty-three plum varieties with different flesh and skin color were anal yzed for their antioxidant content and AOA. Total phenolics, anthoc yanins, and carotenoids were analyzed spectrophotometricall y. AOA was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH). Carotenoid content was higher in yellow-flesh (2-3 mg i-carotene/100 g fwfresh weight) than in white or red-flesh peaches (0.01-1.8 mg j-carotene/100 g fw). AOA was about 2-fold higher in red-flesh varieties than in white/yellow-flesh peach varieties. Among the peaches, the AOA was best correlated with phenolic content. Among the plums, the anthocyanin content increased with the red color intensity. Although the plums varied widely in phenolic content, the red/purple-flesh plums generally had higher phenolic content (400-500 mg chiorogenic acid/1100 g fw) than the other plums. Carotenoid content in plums was similar for all varieties. AOA tended to be higher in red/purple-flesh varieties as compared to light colored flesh plums. As with the peaches, the best correlations were between the AOA and the total phenolics content of the fruit.