Co-Authors:
Kashash, Y., Dept. of Postharvest Science of Fresh Produce, ARO, the Volcani Center, P.O. Box 6, Bet Dagan, Israel, The Robert H. Smith Faculty of Agricultural, Food and Environment Sciences, the Hebrew University of Jerusalem, Rehovot, Israel
Mayuoni-Kirshenbaum, L., Dept. of Postharvest Science of Fresh Produce, ARO, the Volcani Center, P.O. Box 6, Bet Dagan, Israel
Goldenberg, L., Dept. of Postharvest Science of Fresh Produce, ARO, the Volcani Center, P.O. Box 6, Bet Dagan, Israel
Choi, H.J., Postharvest Research Team, National Institute of Horticultural and Herbal Science, Wanju-gunJeollabuk-do, South Korea
Porat, R., Dept. of Postharvest Science of Fresh Produce, ARO, the Volcani Center, P.O. Box 6, Bet Dagan, Israel
Abstract:
The optimal storage temperatures for ‘Wonderful’ pomegranates are between 5 and 7.5 °C. However, application of a cold-quarantine disinfestation treatment against the Mediterranean fruit fly (Ceratitus capitate) requires exposure to a much lower temperature – below 1 °C – for at least 14 days; conditions that often cause chilling injury (CI) symptoms, manifested in surface pitting and internal browning of the white spongy tissue and inner membranes. We demonstrated that harvest time had a remarkable effect on fruit chilling tolerance: early-harvested fruits were very susceptible to CI and were severely damaged after 4 weeks of exposure to 1 °C followed by an additional week at a shelf-life temperature of 20 °C, whereas late-harvested fruits were rather chilling tolerant and showed hardly any CI symptoms after similar exposure. In addition, we developed a postharvest low-temperature-conditioning (LTC) treatment for ‘Wonderful’ pomegranate fruits; it involves exposure to a moderate temperature of 15 °C for 10 days before transfer to the cold-quarantine treatment. When this proposed LTC treatment was applied to mid-season fruits, it entirely prevented the appearance of CI symptoms after 4 weeks storage at 1 °C followed by one additional week at 20 °C, without impairment of fruit-quality parameters, as manifested in loss of weight, flavor, juice total soluble solids and acid contents, and total antioxidant activity. Overall, these findings demonstrate that harvesting mid- and, preferably, late-season fruits, and applying a pre-storage LTC treatment at 15 °C for 10 days, enables export of ‘Wonderful’ pomegranates to new markets that require cold-quarantine disinfestation treatments against the Mediterranean fruit fly. © 2016 Elsevier B.V.