Different responses of goldenberry fruit treated at four maturity stages with the ethylene antagonist 1-methylcyclopropene

Goldenberries (Physalis peruviana L.) were harvested at four different maturity stages: immature green (IG), mature green (MG), yellow (Y) and orange (OR). Fruit were treated or not with 1-methylcyclopropene (1-MCP) at 25 °C for 20 h and then kept at 20 °C for 8 d. 1-MCP gas concentrations used were 0, 0.5 or 5 μL L−1. Application of 1-MCP delayed the onset of the ethylene climacteric in IG and MG fruit in a dose-dependent fashion, and transiently decreased ethylene production in Y and OR fruit. 1-MCP application transitorily decreased the respiration rate in MG fruit and, to a lesser extent, in IG and Y fruit. In contrast, 1-MCP-treated OR fruit displayed higher respiration rates than control fruit throughout the experimental period. Fruit treated with 5 μL L−1 1-MCP showed for 6 d average CO2 production levels approximately 41% higher than those of control fruit, with a respiration rate up to 76% higher on day 4. The hue angle was higher in 1-MCP-treated Y goldenberries than in control fruit for 8 d but differences between MG treated and untreated fruit were recorded only at the end of the experiment. In contrast, no differences were detected in IG and OR fruit. 1-MCP-treated fruit were not consistently firmer than untreated fruit during storage. Also, 1-MCP had no effect on soluble solids or ascorbic acid contents. 1-MCP application did not prevent decay in OR fruit but reduced its incidence thus suggesting that it may influence pathogen infection and development in ripe goldenberries.