The effect of 1-methylcyclopropene (doses of 1-MCP) on pulp softening (through firmness and magnetic resonance imaging), development of the stalk abscission layer, respiratory behavior and postharvest quality of Galia 'Solar King' muskmelon was evaluated. Fruits from the Mossoró-Assú Agricultural Region in Rio Grande do Norte State, Brazil, were harvested when the stalk area was intact and treated with a solution of Imazalil fungicide and the Megh Wash wax, both at a concentration of 20 ml 10 L-1. The fruits were treated with 1-MCP at concentrations of 0; 100; 300 and 900 nl L-1, and stored at 24.5 ± 0.9ºC and 86.4 ± 7.9% RH for 0; 4; 8; 12; 16 and 20 days. The experiment used a completely randomized design in a 4x6 factorial arrangement with four replicates. 1-MCP reduced the respiratory rate of fruits and delayed the peak in ethylene production, pulp softening and the development of the stalk abscission layer. There were no effects of 1-MCP on mass loss, total tititrable acidity, pH, total soluble solids content, total soluble sugars content and external appearance. However, the internal appearance of 1-MCP treated fruits was better, particularly those exposed to 300 nl L-1. This concentration also resulted in a lower respiratory rate, firmer fruits and a slower development of the stalk abscission layer.
Cucumis melo var cantaloupensis; ethylene; firmness; NMR imaging; respiratory rate; 1-MCP
