Controlled atmosphere storage alleviates internal browning in flat peach fruit by regulating energy and sugar metabolisms.

Flat peach fruit are cold-sensitive and vulnerable to chilling injury (CI), particularly internal browning (IB) during cold storage, which limits the consumer acceptance and market value of the fruit. Controlled atmosphere (CA) has been used to alleviate IB in fruit. However, the mechanisms of CA on IB in peach remains unknown. This study investigated the effects of CA (3-3.5% Oxygen, 3-3.5% Carbon dioxide, and 93-94% nitrogen) treatment on IB development, sugar metabolism, and energy metabolism in cold-stored (1 ± 0.5°C) peach. The CA treatment effectively inhibited the development of IB and markedly inhibited the reduction of sugar contents and energy charge. The protein expression of the V-type proton ATPase subunit was significantly inhibited by the CA treatment, accompanied by higher adenosine triphosphate (ATP) content, and energy charge than the control fruit. Notably, the expressions of the pyruvate kinase family of proteins, pyruvate decarboxylases, and sucrose synthase were induced by CA...