Exogenous β-ionone treatment improved the cold tolerance of postharvest peach fruit by reducing oxidative damage

Peaches are highly susceptible to chilling injury during postharvest storage, causing significant nutrient loss. This study found that 0.1 mM β-ionone treatment significantly delayed the onset and progression of chilling injury. The treatment enhanced free radical scavenging capacity and ferric reducing ability, while increasing the activity and gene expression of key antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). These effects collectively improved the reactive oxygen species (ROS) scavenging capacity and chilling tolerance of the fruit. β-ionone also upregulated genes involved in glutathione (GSH) and ascorbic acid (AsA) biosynthesis and downregulated phenolic catabolism genes, slowing the degradation of these antioxidants. As a result, treated peaches maintained higher levels of AsA, GSH, and total phenolics than controls. This study provides novel evidence that exogenous β-ionone enhances postharvest cold hardiness in peaches by regulating both enzymatic and non-enzymatic antioxidant systems, offering a theoretical basis for improved fruit preservation strategies.