Effect of exogenous application of putrescine on storage behaviour of jamun (Syzygium cumini Skeels) fruits

Jamun is an important underutilized minor fruit of tropics rich in antioxidants and having neutraceutical values. Fruits are highly seasonal and possess very short shelf life. With intent to increase the useful life of fruits, they were treated with 1 mM putrescine (PUT) for 5 min. Various physico-chemical parameters like physiological loss in weight (PLW), firmness, respiration rate and TSS were recorded daily up to 4 days period under ambient condition. Fruits treated with PUT recorded minimum PLW of 4.58% as compared to control (5.80%) at the 4^th day of storage. Fruits treated with 1 mM PUT maintained higher firmness (145.2, 131.4, 128.06, 120.16 at 1^st, 2^nd, 3^rd and 4^th days, respectively) while, untreated fruits recorded rapid loss of firmness during storage. There was significant difference with respect to respiration rate. Fruits treated with 1 mM PUT registered lower respiration rates (127.87 mL CO₂ kg^‑1 h^‑1) while untreated fruits recorded higher (186.59 mL CO₂ kg^‑1 h^‑1) respiration rates. Untreated jamun fruits registered maximum changes in TSS (18.33 °Brix) at the 1^st day to 12.25 °Brix at the 4^th day. However, postharvest treatment of 1 mM PUT for 5 min recorded significantly minimum changes in TSS (18.30 at 1^st to 13.66 °Brix at the 4^th day). In conclusion, postharvest dip treatment of 1 mM PUT for 5 min effectively delayed physico-chemical and physiological changes in jamun fruits under ambient storage.