Improving shelf life of pre-ripe and ripe ‘Galia’ melon fruit by 1-MCP

Abstract

Galia melons (cucumis melo L. var. reticulates ‘True Galia’) harvested at pre-ripe and ripe stages were treated with 5 uL.L-1 1-methylcyclopropene (1-MCP) for 18 h at 200C and stored at the same temperature. Respiration and ethylene production, mesocarp firmness, soluble solids concentration, electrolyte leakage, pH, titratable acidity, and visual changes were noted for the period of storage. 1-MCP not only delayed the respiratory climacteric peak 10 days but reduced the respiration rate as well. In contrast, the respiration pattern of ripe fruit was not significantly affected by 1-MCP. Peak climacteric ethylene production of pre-ripe fruit treated with 1-MCP was delayed 6 days and reduced by 65%. 1-MCP resulted in higher ethylene production rate in ripe fruit (68%) from day 3 to the end of storage. Fruit treated with 1-MCP at the pre-ripe stage demonstrated higher firmness values throughout storage compared with control. Firmness was 11.1 N in pre-ripe fruit on day 11 (last day of control fruit), while only 2.4 N in pre-ripe control. The firmness was also higher (67%) in ripe 1-MCP-treated fruit after day 3: Ripe 1-MCP-treated fruit, were 1406 N and 12.2; and ripe control fruit, were 5.04 N and 4.85 on day 5 and 9, respectively. Loss of titratable acidity and green rind color was delayed by 1-MCP in both pre-ripe and ripe fruit. Electrolyte leakage of mesocarp tissue was lower in 1-MCP-treated, compared with control fruit, in both pre-ripe (throughout storage) and ripe fruit (after day 6). Windows of edibility of both pre-or ripe 1-MCP- treated fruit was extended by 40 to 50%.