Abstract 

Jujube or Indian jujube (Ziziphus mauritiana Lamk.) belongs to Rhamnaceae family. It is a white fleshed fruit with pleasant aroma. Jujube fruit is highly enriched with ascorbic acid, phenolics, vitamin A, vitamin B, calcium, phosphorus and iron. Due to high perishability, it exhibits limited shelf and storage life, which limits its marketability and quality. Hence, this study was done to investigate the influence of postharvest applications of methionine and melatonin on storage quality of jujube fruit under cold storage conditions. In this experiments, jujube fruits cv. ‘Umran’ were treated with methionine and melatonin at different concentrations viz. T0 = control, T1 = 0.25 % methionine, T2 = 500 μM melatonin, T3 = 0.25 % methionine + 500 μM melatonin. The treated fruits kept under cold storage at 7 °C with 80±90 % relative humidity for 24 days. To evaluate change in quality, changes in physical, biochemical, organoleptic, phytochemicals and enzymatic parameters were measured at 4 days interval for cold storage. Experiment was conducted according to Completely Randomized Design with four treatments and three replications. Data were analysed statistically by applying ANOVA and LSD to evaluate the best treatment. The results showed that application of 0.25 % methionine was must suitable for maintaining higher quality parameters of jujube like fruit firmness (64.93 N), weight loss (10.00 %), chilling injury (1.07 score), decay (1.63 score), peel colour (5.4 score), overall acceptability (5 score), total soluble solids (13.01 °Brix), titratable acidity (0.75 %), ascorbic acid (84.30 mg 100 mLˉ¹ FW), activities of peroxidase (160.70 U μg̵¹ protein) and catalase activity (7.45 U μg̵¹ protein) under cold storage. It is concluded that postharvest application of 0.25 % methionine, 500 μM melatonin and 0.25 % methionine + 500 μM melatonin can be used for maintaining higher storage life of jujube.