Dynamics of enzymatic and non-enzymatic antioxidants in Japanese plums during storage at safe and lethal temperatures

We investigated the effect of storage temperature as a function of storage time on lipid peroxidation, enzymatic and non-enzymatic antioxidants of Japanese plums (Prunus salicina Lindl.). Commercially mature fruit of 'Amber Jewel' cultivar were stored at 0 °C (recommended temperature) and 5 °C (lethal temperature) for 6 weeks. Chilling injury (CI) symptoms in the form of flesh browning and flesh translucency were noticed after 4 weeks of storage at 0 °C and 5 °C, respectively. The lipid peroxidation as reflected by thiobarbituric acid-reactive substances concentration was significantly higher at 5 °C beyond 2 weeks of storage than at 0 °C. The activities of superoxide dismutase, catalase, and peroxidase were significantly higher during storage at 5 °C than at 0 °C. The activities of monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase, increased during the first 2 weeks of storage at 5 °C and helped maintaining ascorbate pool better than at 0 °C. Overall, the response of antioxidative system to chilling stress at 5 °C was comparatively faster and stronger than at 0 °C, but it could not sustain for 6 weeks of storage as the higher levels of oxidative stress associated with fruit ripening at 5 °C might have resulted in failure of the antioxidative protection system.

► Storage temperature and duration impact postharvest oxidative stress in plums. ► Lipid peroxidation increased with storage and was higher at 5 °C compared to 0 °C. ► Response of antioxidant protection system was stronger at 5 °C than at 0 °C. ► Reactive oxygen species load might have exceeded antioxidative capacity at 5 °C. ► Oxidative injury was more in fruit stored at 5 °C than at 0 °C.