Action of ethylene and 1-MCP on the quality of nasturtium flowers

Abstract

The purpose of this study was to determine the effect of ethylene and 1-methylcyclopropene (1-MCP) on the postharvest quality of nasturtium flowers (Tropaeolum majus), by evaluating the mass loss and anthocyanin content of flowers harvested at four different stages of opening. For this, three experiments were performed: only 1-MCP, only ethylene, and 1-MCP combined with ethylene. In both experiments with 1-MCP and ethylene, the flowers were maintained for 24 h with different concentrations of the products. For ethylene, the concentrations used were 0.0, 0.1, 1, 10, 100 and 1000 μL L-1 and for 1-MCP, we used concentrations of 0.0, 0.5, 1.0 and 1.5 μL L-1. For 1-MCP, only the concentration 1.5 μL L-1, was applied for 24 h, then the flowers were exposed to ethylene (100 μL L-1) for a further 24 h, and two controls, inside and outside the airtight chambers. The fourth stage showed the greatest weight loss in response to ethylene at the end of 96 h of assessment in relation to other stages. Ethylene had greater effects on the flowers fully open. In all stages evaluated 'bent neck' effect was observed in response to ethylene, which was inhibited when the flowers were treated with 1-MCP. 1-MCP is effective in preventing the deleterious effects of ethylene, even in the presence of exogenous ethylene. The ethylene at a maximum rate influenced the anthocyanin content, possibly due to greater dehydration of flowers, i.e., greater loss of fresh weight, since the 1-MCP had no influence.