Defining safe O₂ thresholds for long-term dynamic controlled atmosphere storage of mangoes

Brazilian mango exports to distant markets require postharvest technologies that complement refrigeration, such as the use of dynamic controlled atmosphere (DCA). Establishing the anaerobic compensation point (ACP), which is the minimum O₂ concentration required to inhibit aerobic respiration without inducing irreversible anaerobic metabolism, is essential for defining appropriate DCA conditions. This study evaluated whether the temporal dynamics of the ACP during cold conditions differed among mango cultivars and growing seasons. ‘Tommy Atkins’ and ‘Palmer’ mangoes produced during the summer and winter seasons were stored at 9 °C and 90–95% relative humidity, and the ACP was determined weekly over six weeks as the O₂ partial pressure at the onset of ethanol production. The temporal response varied markedly among cultivar–season combinations. In ‘Tommy Atkins’, ACP ranged from 0.2 to 13.8 kPa during summer but remained between 0.8 and 2.3 kPa during winter. Conversely, ‘Palmer’ mangoes exhibited a narrower range during summer, from 0.3 to 3.8 kPa, whereas winter-produced fruit required O₂ partial pressures of up to 11.1 kPa. During the first three weeks of storage, ACP values remained low (≤2.3 kPa) across cultivar–season combinations. However, in subsequent weeks, the safe O₂ threshold increased sharply, reaching 13.8 kPa in summer-produced ‘Tommy Atkins’ mangoes and 11.1 kPa in winter-produced ‘Palmer’ fruit. These findings demonstrate that minimum O₂ requirements vary according to cultivar, growing season, and storage duration. Therefore, DCA protocols that are cultivar-specific and seasonally adjusted based on physiological variations observed during storage are essential for optimizing mango storage and enabling long-distance international trade.