Antioxidant Content of Peach and Plum Genotypes

Abstract

Stone fruits contain a range of phenolic compounds 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. Twenty-two peach varieties and fifty-three plum varieties with different flesh and skin color collected from fields in California, Georgia, and Texas were analyzed for their antioxidant content and AOA. Total phenolics, anthocyanins, carotenoids were analyzed spectrophotometrically. AOA was evaluated by DPPH. Anthocyanin and phenolic contents were higher in red-flesh than in white/yellow-flesh peaches. Carotenoid content was higher in yellow-flesh [2-3 mg β-carotene/100 g fw (fresh weight)] than in white or red-flesh peaches (0.01-1.8 mg β-carotene/100 g fw). AOA was about 2-fold higher in red-flesh varieties than in white/yellow-flesh varieties. Among the peaches, the AOA was well correlated with both phenolic and anthocyanin 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 chlorogenic acid/100 g fw) than the other plums. Carotenoid content in plums was similar for all varieties (0.2-2 mg β-carotene/100 g fw). AOA was higher in red/purple-flesh varieties; however, it was well correlated only with the phenolic content in light colored flesh plums. These results suggest that red-flesh peach varieties have a greater potential health benefit based on antioxidant content and AOA as compared to the white/yellow-flesh varieties. Although this trend is not clear over all the plum varieties; the red/purple-flesh plums usually have higher antioxidant content and AOA.