Effects of exogenous oxalic acid on ripening and decay incidence in mango fruit during storage at controlled atmosphere

Experiment was carried out with the fruit of Shengxin mango cultivar (Mangifera indica L.). The fruit were dipped in 0 (as control) and 5 mmol/L oxalic acid solutions for 10 min, respectively, and then stored at controlled atmosphere(6% CO2+ 2% O2, 14±1℃). Changes in flesh firmness, soluble solid content (SSC), pH value, disease index and fruit decay, production of active oxygen species (AOS), such as superoxide ( ) and hydrogen peroxide (H2O2), content of reduced forms of ascorbate (ASA) and glutathione (GSH), and superoxide dismutase (SOD) activity in fruit were investigated during storage. The results showed that, as compared with control, in treated fruit, flesh firmness presented high, increases of SSC content were alleviated, and disease index and fruit decay decreased as well. Moreover, AOS production was inhibited, and ASA loss was reduced and increasing SOD activity was induced by oxalic acid treatment. It was suggested that the effects of exogenous oxalic acid on enhancement of antioxidant capacity and decrease of AOS production were associated with retardation of the ripening process and decrease of decay incidence in mango fruit during storage, and oxalic acid treatment was an alternative method for prolonging the storage life of mango fruit.