Effects of 1‐Methylcyclopropene and Hot Water Quarantine Treatment on Quality of “Keitt” Mangos

The optimal 1‐methylcyclopropene (1‐MCP) treatment to slow ripening of whole “Keitt” mangos, either alone or in combination with hot water treatment (HWT) (prior to or post 1‐MCP) was identified. USDA‐APHIS mandates that HWT can be used for control of fruit flies, but this may affect fruit response to 1‐MCP. Mangos were evaluated by repeated measurement of nondestructive firmness, peel color, and ethylene production on the same mango fruits during 2 wk of ripening at 20 °C after treatment. The magnitude of ethylene production increased as a result of both 1‐MCP and HWT. With softer mangos (65 N), treatment with 1‐MCP alone delayed fruit softening and extended the number of days to full‐ripeness (25 N) from 5 d in untreated fruit to 11 d. For these riper fruit, application of 1‐MCP prior to HWT extended the days to full‐ripeness to 9 d compared with 7 d when 1‐MCP was applied after HWT. With firmer mangos (80 N), 1‐MCP treatments alone prolonged the days to full‐ripeness to 13 d as compared to 11 d for the untreated fruit. There was no significant concentration effect on firmness retention among 1‐MCP treatments (0.5, 1.0, or 10.0 μL/L). HWT resulted in a faster rate of fruit softening, taking only 7 d to reach full‐ripeness. Combining 1‐MCP with HWT reduced the rate of softening compared to HWT alone, resulting in 9 to 11 d to full‐ripeness. Application of 1‐MCP before HWT showed a greater ability to reduce the rate of fruit softening compared with 1‐MCP treatment after HWT.