Impact of γ-aminobutyric acid and 1-methylcyclopropene on qualitative attributes of apples (Malus domestica Borkh. cv. Fuji) during cold storage

This study investigated the efficacy of γ-aminobutyric acid (GABA, 1.0 mM) and 1-methylcyclopropene (1-MCP, 1 µL L⁻ ¹), individually and in combination, in mitigating watercore disappearance, flesh browning, and postharvest quality in apples during 180 days storage. The results showed that the combined GABA + 1-MCP treatment outperformed individual applications, significantly delaying watercore disappearance by preserving sucrose and sorbitol while moderating glucose and fructose accumulation. Furthermore, the combined treatment significantly reduced flesh browning compared to the control, likely attributed to suppressed polyphenol oxidase activity and enhanced antioxidant capacity. This approach also minimized weight loss and maintained firmness and titratable acidity. Although total phenolics and total flavonoids increased progressively during storage, their levels were effectively regulated by the GABA + 1-MCP treatment. These results indicate that the combined exogenous application of GABA and 1-MCP is a potentially effective method to improve postharvest quality, and enhance storage efficiency of apple fruit.