Impact of 1-MCP and hot water treatment on postharvest quality of pomegranate fruit

Pomegranates are commonly stored in Iran at temperatures higher than 10°C and RH≈70%. At this storage condition, the fruit are affected by desiccation and loss of quality. In this experiment, the effect of SmartfreshTM (1-MCP) at 1 µl L(-1) with hot water treatment (HWT) at 50°C for 5 min and the combination of these two treatments (SmartfreshTM+HWT) were studied in reducing the mentioned problems in ‘Malas Saveh’ pomegranate fruit. Untreated fruit was used as the control. The fruit were stored at 13°C for 45 days and thereafter, fruits were held further at 20°C for 7 days as a simulated shelf life. Fruit firmness, colour parameters and skin-shriveling index were evaluated at the end of storage and after holding, but the fruit quality characteristics were determined only after holding at 20°C. Results showed that the fruit firmness of SmartfreshTM treated fruits was higher than that of other treatments after storage, but after holding, there were no significant differences in fruit firmness among the tested treatments. HWT treated fruit, in contrast with other treated fruit, had lower L* value than the control fruit after storage and after holding. There were no significant differences in a* and b* among the treatments in this trial. The skin-shriveling index of SmartfreshTM treated fruits was significantly lower than that of other treatments after storage and after holding. The skin-shriveling indexes of HWT and SmartfreshTM+HWT treatments were lower than that of control after holding, while after storage, no significant differences in skin-shriveling indexes were observed among them. Fruit treated with SmartfreshTM had highest titratable acidity and lowest total soluble solids compared to other treatments. Titratable acidity of control fruits was lower than that of HWT and SmartfreshTM+HWT treatments, but there were no significant differences among the control, HWT and SmartfreshTM+HWT treatments in total soluble solids. SmartfreshTM treated fruit had greatest aril moisture and medium juice colour among the tested treatments at this experiment. Overall, SmartfreshTM treatment was more effective than hot water and combination treatments in maintaining the postharvest quality of pomegranate fruit during storage and under holding.