Enhanced chilling tolerance of banana fruit treated with malic acid prior to low-temperature storage

• Malic acid (MA) alleviated chilling injury symptoms under 6 °C in banana fruit skin.
• MA involved in reduced ROS level, and suppressed activities of PPO and POD.
• MA retarded rapid decline of total phenolics and enhanced antioxidant activities.
• MA treatment showed potential for alleviating chilling injury to banana fruit.

The effects of postharvest malic acid (MA) treatment on alleviating the occurrence of chilling injury (CI) symptoms in banana (Musa spp., AAA group, cv. Brazil) fruit under 6 °C were evaluated. Application of 80 mM MA alleviated CI symptoms (surface browning), delayed the decrease in chlorophyll fluorescence (Fv/Fm) and chlorophyll content. The activities of peroxidase (POD) and polyphenol oxidase (PPO) were also suppressed by MA. Furthermore, compared with the control group, fruit that were treated with MA showed lower levels of reactive oxygen species, but higher antioxidant activities. The results suggest that the application of MA, as an organic acid, exhibited the potential for alleviating chilling injury symptoms of banana fruit by reducing skin browning and inducing antioxidant activities under low temperature.