1-MCP may increase commercial life and storage potential of melon fruits

Melons (Cucumis melo L. cv. Piel de Sapo) are very sensitive to chilling injury (CI) under low-temperature storage. CI induces small brown pits and necrotic areas on the skin that increase their intensity after transfer of the fruit from low temperature to 20?C. Ethylene plays a key role in many developmental processes and in the response of plants to different biotic and abiotic stresses. Towards the understanding of the involvement of ethylene in the responses to cold in the skin tissue, fruits were treated with 0, 0.5 and 1 mL L?1 1-methylcyclopropene (1-MCP) immediately after harvest for eight hours and subsequently were stored in air at 2?C for up to 21 days. The level of oxidative stress through enzymatic antioxidant activities like superoxide dismutase (SOD) peroxidase (POX), catalase (CAT), non-enzymatic systems (ascorbic acid) total antioxidant capacity (trolox equivalent antioxidant capacity (TEAC) were determined. Damage on skin membranes was established by measuring of ion leakage and ethylene production was monitored. The changes in antioxidant potential of melon fruits were related to the capacity of 1-MCP to increase their commercial life. Loss of firmness was significantly lower in 1-MCPtreated fruits. In addition, 1-MCP-treated fruits (1 mL L?1) exhibited lower levels of ethylene production and higher activities of superoxide dismutase, peroxidase and catalase. Treated fruits also exhibited better retention of ascorbate and higher trolox equivalent antioxidant capacity during storage. In accordance with these observations, lower ion leakage values were detected in 1-MCP-treated melons. Results suggest that 1-MCP conferred a greater resistance to oxidative stress, reducing the incidence and severity of CI. This, along with the reduction in ethylene production, could contribute to the increase in commercial life and storage potential of melon fruits. [Acknowledgements: Regional Centre Study of Healthy Foods, CONICYT-REGIONAL, GORE Region of Valpara?so, project R12C1001]. SourcesBlocking of ethylene perception modulates the enzyme antioxidant system and increase the chilling tolerance of Spanish melon fruitM. Valdenegro1, L.Fuentes1, R.Simpson1,21Regional Centre Study of Healthy Foods (CREAS), CONICYT-Regional GORE, Valpara?so, Chile2Department of Chemical and Environmental Engineering, Universidad Tecnica Federico, Santa Maria, Valpara?so, ChileM?nica Valdenegro, mvaldenegro@creas.clV Postharvest Unlimited, ISHS International Conference, 10-13 June 2014, Cyprus,http://web.cut.ac.cy/postharvest/ Picture is melon ?Cordial F1?, Sakata Key words Poscosecha ???postcosecha ???postharvest ???na-oes ????? ??? ?????? ????? ????? ?post-r?colte ??????? ?? ????????? ????? na-oogst ???post-raccolta ???Obr?bka po ???p?s-colheita ????????????????? ???hasat sonras? ????? ?Ernte ????????????????? ??????? ??????????? ???postcollita ???poskliz?ov? ????? ????? ? ????? nakon branja ???pozberov? ????? ?obdelovanje zemlje po ???post-colleita ???????? ????? ???pascapanen ????il?onn postharvest ??????? ???p?c ra?as ???derliaus apdirbimas po ???lepas tuai ????? ?? ?????? ???post-recoltare ????????? ????? ???????????????????? ?????????????? ?????????????????? ???sau thu ho?ch ?????????????????? ???zangemva kwenkathi yokuvuna Mel?n ????? ?melon ???waatlemoen ??????? ???? ???melono ????? ?????? ???????? ???meloen ???melone ????? ??? mel?o ??????? ???kavun ???????? ????? ??? ??? ??? ??? ???