Endogenous nitric oxide production induced by pulsed electric field modulates postharvest quality of mango.

The rapid ripening and oxidative damage of mango are primary causes of quality deterioration. Nitric oxide (NO) is known to effectively inhibit ethylene biosynthesis and enhance antioxidant system, making endogenous NO induction a promising strategy to delay senescence. This study proposes a novel method for in situ generation of NO in mango using pulsed electric field (PEF) treatment, and investigates the internal antioxidant system and actual preservation effects during 24-day storage. Our results demonstrated that optimal PEF treatment (0.54 kV/cm, 27.8 min, 146 Hz) significantly delayed fruit senescence and maintained postharvest quality. Mechanistically, PEF treatment induced a sustained 12-h burst in endogenous NO levels by enhancing nitric oxide synthase (NOS) and nitrate reductase (NR) activities, leading to an 8.46-36.02% increase in NO content throughout storage. This NO burst consequently activated the fruit's antioxidant defense system, upregulating both enzymatic and non-enzymatic antioxidants. As a result, PEF-treated fruit exhibited reduced reactive oxygen species (ROS) accumulation and lipid peroxidation (MDA content), along with suppressed respiration rates and ethylene production. Correlation analyses further confirmed that PEF-induced NO generation was tightly associated with enhanced antioxidant capacity and reduced oxidative damage. This study provides the first evidence linking PEF treatment to NO-mediated redox homeostasis in mango, suggesting a potential mechanism by which physical stimulation may influence fruit senescence. Our findings establish PEF as an effective green technology for extending the shelf-life of mango and potentially other tropical fruits, offering both theoretical insights and practical implications for postharvest management.