Effect of postharvest hydrogen sulphide on lignification and biochemical markers of pointed gourd.

Hydrogen sulphide (H2 S) has emerged as a gasotransmitter molecule that modulates several physiological functions in plants, specially, different biotic and abiotic stresses. Pointed gourd (PG) fruits start losing their soft texture and appealing colour within 2-3 days of harvest, resulting in poor marketability and shelf life. Here, the effect of exogenous H2 S (1 and 2 mm) application on lignification and other biochemical markers linked to ripening, shelf-life and edible quality of PG was assessed during cold (12 °C, 85-90% RH) and ambient (27 ± 2 °C, 55 ± 5% RH) storage. The synergistic effect of H2 S was recorded during simulated storage at ambient conditions. Postharvest H2 S treatment (1 mm) effectively delayed yellowing and chlorophyll loss (four-fold reduction) and maintained the phenolic content and higher antioxidant activity (36%). The H2 S-treated PG fruits had significantly lower lignification and membrane permeability i.e. 15% and 13%, respectively, than control samples. H2 S-treated fruit also maintained higher PAL and lower PPO activity. Therefore, postharvest application of H2 S (2 mm) could be effective in maintaining postharvest quality of PG fruits and extending the marketing period.