Metabolic basis for superior antioxidant capacity of red-fleshed peaches

Peach fruit is an important natural source of phenolic compounds that are well-known to have health benefits, but their metabolic basis remain elusive. Here, we report on phenolic compounds accumulation and antioxidant activity of ripe fruits in peach. A considerable variation in phenolic compounds content was observed among peach germplasm, with significantly higher levels detected in red-fleshed peaches compared to non-red-fleshed peaches. Antioxidant activity of crude extracts from ripe fruits showed significant differences among peach germplasm, with red-fleshed peaches having the strongest antioxidant activity. Intriguingly, it was observed that total phenolics instead of anthocyanins were strongly associated with antioxidant activity. Phenolic compounds content and antioxidant activity showed dynamic changes throughout fruit development, and these were much higher in the peel than in the flesh. Metabolomic analysis unveiled a coordinated accumulation of anthocyanins as well as key components of flavonoids and phenolic acids, which endows red-fleshed peaches with superior antioxidant activity.