Abstract: Peach ( Prunus persica L.‘Bayue Cui’) fruit were dipped in a 5 mmol·L ^{- 1} oxalic acid solution for 10 min and then stored at low temperature for 20 days. Changes in antioxidant ability and polyphenol oxidase ( POD) activity in the fruit were investigated during storage. The results showed that, as compared
with control fruit, higher activities of superoxide dismutase ( SOD) , peroxidaes ( POD) , catalase (CAT) and PPO were observed and lose of ascorbate acid (AsA) was delayed. Moreover, to some extent, active oxygen species (AOS) production including superoxide (O₂· ) and hydrogen peroxide (H₂O₂ ) was inhibited in treated fruit. Itwas suggested that effects of oxalic acid on increases of antioxidant ability and PPO activitymight be beneficial in delaying ripening process and enhancement of disease resistance in peach fruit during storage at low temperature.

Key words: Peach, Exogenous oxalic acid, Low temperature, Antioxidant enzyme, PPO, AOS, Storage