Sodium Nitroprusside Treatment Delays Ripening and Maintains Postharvest Quality of Purple Passion Fruit During Cold Storage

Purple passion fruit is highly perishable due to its climacteric ripening behavior, necessitating effective preservation methods; however, existing postharvest technologies are often constrained by high costs and operational complexity. This study evaluated the potential of sodium nitroprusside (SNP), a cost‐effective nitric oxide (NO) donor with a simple application method, to inhibit ethylene biosynthesis and extend the postharvest shelf life of purple passion fruit ( Passiflora edulis Sims.). Fruits were treated with SNP at concentrations of 1.0, 1.5, 2.0, and 2.5 mM for 20 min, compared with untreated control. Samples were stored at 5 ± 1 and 85 ± 5% relative humidity and evaluated at 5‐day intervals. Results showed that 1.5 mM SNP significantly reduced ethylene production; inhibited ACC synthase (ACS) and ACC oxidase (ACO) activities; and maintained firmness, total soluble solids (TSS), and vitamin C content, while minimizing weight loss and decay, thereby extending shelf life to 35 days. The integrated quality retention index (QRI), supported by correlation analysis and principal component analysis (PCA), consistently identified 1.5 mM SNP as the optimal treatment. Based on these findings, a putative regulatory mechanism is proposed in which SNP‐derived NO inhibits key steps in the ethylene biosynthesis pathway, providing a practical and promising strategy for postharvest handling of purple passion fruit.