Cold plasma treatment maintains antioxidant capacity and cell membrane integrity in apricot fruit by inducing reactive oxygen species scavenging systems

Postharvest storage quality is a major concern in the fruit industry, which directly affects consumer acceptance and market value. In this research, we explored the impacts of cold plasma (CP) treatments (30 kV, 93 kV, and 150 kV) on storage quality of apricot fruit, and explored the regulatory mechanisms of reactive oxygen species (ROS) metabolism and ascorbate-glutathione (AsA-GSH) cycling. Compared with control (CK), CP treatment effectively decreased fruit decay incidence, and delayed the decline in total soluble solids (TSS) and titratable acidity (TA). The 30 kV treatment had relatively little influence on maintaining freshness, while 150 kV treatment caused irreversible damage to fruit surface. However, 93 kV treatment induced the generation of appropriate ROS levels, triggering the defense response of the ROS metabolic system, which upregulated gene expression and enzyme activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR). It also promoted the synthesis of antioxidant substances including total phenols, total flavonoids, glutathione (GSH), and ascorbic acid (AsA), enhancing overall antioxidant capacity of fruit. This effectively lowered hydrogen peroxide (H₂O₂) and superoxide anion (O₂·⁻) levels, thereby reducing cell membrane permeability (CMP) and malondialdehyde (MDA) content. In conclusion, 93 kV CP treatment alleviated oxidative damage to cell and mitochondrial membranes by regulating ROS homeostasis and AsA-GSH cycling, effectively maintaining storage quality of apricot fruit.