Biochemical and physiological responses of pointed gourd ( Trichosanthes dioca Roxb.) to salicylic acid and sodium alginate post-harvest treatments

Due to moisture loss, chlorophyll degradation, skin yellowing, and shriveling, the marketability of pointed gourd fruit is significantly diminished after harvest. This study examined the effect of salicylic acid and sodium alginate coating treatment on senescence and fruit quality characteristics of pointed gourds under ambient storage conditions. Fruits, either alone or in conjunction with salicylic acid (2 mM and 3 mM), were covered with a sodium alginate (2%) solution (w/v) for 5 minutes. Compared to the control, fruits treated with 3.0 mM salicylic acid + sodium alginate (2%) showed reduced weight loss (17.41%), maintained higher levels of chlorophyll (5.11 mg/g FW), and decreased malondialdehyde content (0.71 mg/g FW). The same treatment also showed higher ascorbic acid (3.67 mg/100 g FW) and higher total phenol (61.51 µg GAE/g FW) than the untreated group. However, after 6 days of storage, there was no discernible change in the total antioxidant capacity (1.925 µmol TE/g FW), flavonoids (1.925 µg RE/g FW), and radical-scavenging activity (24.75%) between salicylic acid (3.0 mM) + sodium alginate (2%) treated and untreated fruit. Under ambient conditions, a postharvest salicylic acid treatment can extend pointed gourd marketability up to 6 days after harvest and prevent quality degradation.