Synergistic effect of polyamine treatment and chitosan coating on postharvest senescence and enzyme activity of bell pepper (Capsicum annuum L.) fruit

Abstract

• Combination treatment of spermidine (SPD), spermine (SPM) and chitosan (Ch) as coating for extending shelf life of capsicum fruit. • Fruits were treated with coating solutions SPD and SPM @ 0.5, 1.0 and 1.5 mM, then coated with chitosan and stored at 10 ± 1 °C. • The biochemical parameters, enzymatic activities, antioxidant capacity and quality parameters were assessed in capsicum fruit during storage. • Spermine (1.5 mM) and chitosan 1% treatment showed the lowest weight loss and was adjudged best treatment to extend storability of capsicum fruit cv. “Rehana”. This study investigated the effects of treating bell pepper fruit cv. Rehana by dipping with spermidine and spermine (0.5, 1.0 and 1.5 mM) and coating with chitosan (1%) on fruit quality, bio-active compounds, antioxidant enzyme activities, shelf life and senescence related compounds. The fruit were stored at 10 °C and 80–90% RH for 56 days. The results revealed that synergistic treatment of spermine 1.5 mM and chitosan 1% (T7) was most effective for reducing weight loss, electrolyte leakage, maintaining fruit quality and enhancing antioxidant activity over other treatments during storage. The bell pepper fruit of T7 treatment exhibited lowered weight loss by 47.6%, electrolyte leakage by 62.6%, malondialdehyde accumulation by 28.3% while maintaining higher total phenols by 68.8%, total carotenoid by 21.9%, ascorbic acid by 15%, total chlorophyll by 30.4%, catalase activity by 34.3% in comparison to control (T1) on the last day of storage. Other treatments showed intermediate effects. The results suggest potential beneficial influence of synergistic treatment of polyamines, particularly spermine 1.5 mM with chitosan in extending shelf life of bell pepper by about 28 days relative to control with notable preservation of bioactive compounds, antioxidant enzymes and slowing senescence indicators over untreated fruit.