Abstract
<title>Abstract</title> <p> Mango ( <italic>Mangifera indica</italic> L.) is one of the major tropical fruit crops with immense socioeconomic importance, faces significant post-harvest losses that undermine its commercial value chain. Spermidine (Spd), a naturally occurring triamine polyamine, known to regulate cell division, retard senescence, and modulate ethylene biosynthesis, was evaluated for its effect on physicochemical properties and postharvest longevity of mango var. Amrapali. The experiment was conducted with five treatments (1.0 mM, 1.5 mM, 2.0 mM, and 2.5 mM), with fruits assessed over 15 days of ambient storage. Spd application significantly improved all measured parameters over the untreated control. The fruits treated with 2.5 mM concentration consistently outperformed others, and was found statistically at par with fruits treated with 2.0 mM Spd for majority of the traits. The fruits treated with 2.5 mM Spd recorded higher preserved TSS (21°Brix), better titratable acidity retention (0.16%), elevated ascorbic acid (24.32 mg/100 g pulp), total phenolics (55.66 mg GAE/100 g), carotenoid content (11.76 mg/100 g), and antioxidant activity (0.71 µmol Trolox/g) at the end of storage period. The fruit firmness was better retained (7.66 N), weight loss minimized (24.16%compared to the 48.90% in control), and a substantial reduction in spoilage percentage was observed in the treated fruits. An extended marketable shelf life by six additional days over the control was observed, with all differences being statistically significant. The post-harvest application of the chemical spermidine is thereby, recommended as a novel approach for enhancing mango postharvest quality and minimizing quality deterioration in commercial production systems. </p>