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

Goldenberries (Physalis peruviano 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 degrees C for 20 h and then kept at 20 degrees C for 8d. 1-MCP gas concentrations used were 0, 0.5 or 5 mu LL-1. Application of 1-MCP delayed the onset of the ethylene climacteric in IG and MG fruit in a dose-dependent fashio 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 mu LL-1 1-MCP showed for 6d 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. (C) 2007 Elsevier B.V. All rights reserved.