Effect of 1-methylcyclopropene on 'Rocha' pears stored under normal atmosphere conditions.

摘要

The effects of 1-MCP treatments on the ripening of pear (Pyrus communis) cv. 'Rocha' during a cold storage period of seven months was evaluated throughout three growing seasons (2004-06) in Portugal. At 24 h after harvest, the fruits were treated with 100, 200 and 300 ppb 1-MCP for 24 h at 0 degrees C, and were stored under normal atmosphere conditions at 0 degrees C and 90-95% RH. Fruit samples were removed from storage periodically and pulp firmness, skin colour, soluble solids content (SSC) and titratable acidity (TA) were evaluated, immediately and after a shelf-life period of 7 days. The 1-MCP treatment delayed the loss of pulp firmness and yellowing during the cold storage period. However, the efficacy of 1-MCP on the inhibition of the quality attributes development was affected by the concentration of 1-MCP and the pear maturity stage before the treatment. Pears with a Streif index greater than 0.09 were sensitive to 200 and 300 ppb 1-MCP. The longer the storage period, the greater were the differences detected between the treated and untreated fruits. Ripening during the shelf life period proceeded similarly to that of the untreated fruits, but the 300 ppb-treated fruits had higher pulp firmness and TA and were greener. This concentration seems to be the most appropriate, though sensory analysis should be assessed to confirm it.