บทคัดย่องานวิจัย

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Effect of mechanical harvest and timing of 1-MCP application on respiration and fruit quality of European plums Prunus domestica L.

Felix Lippert and Michael M. Blanke

Postharvest Biology and Technology Volume 34, Issue 3 , December 2004, Pages 305-311

2004

บทคัดย่อ

Effect of mechanical harvest and timing of 1-MCP application on respiration and fruit quality of European plums Prunus domestica L.

Mechanical harvest was simulated by dropping mature but not ripe European plums (Prunus domestica L.) from a range of heights o­nto a plate. These plums were exposed to 0.5 μl l−1 1-MCP either before or after this treatment and cold-stored at 2 °C and 95% relative humidity for 4 weeks. Mechanically harvested European plums lost their firmness during 4 weeks cold storage at 2 °C with Shore firmness values of 52, whereas manually picked control fruit remained sufficiently firm for fresh fruit consumption with fruit firmnessShore values above 60. European plums consumed oxygen at a rate of 1–3 mg kg−1 h−1 with a constant RQ of ca. 1.1, due to CO2 refixation and malic acid as major respiratory substrate, during the 4 weeks of cold storage at 2 °C. Fruit respiration of 32 mg O2 kg−1 h−1 at 20 °C, based o­n Arrhenius plots, was typical of climacteric plums. This rate was halved by 1-MCP during the first 5 days in cold store, an effect which diminished after these 5 days during subsequent shelf-life indicating a temporary effect of 1-MCP o­n fruit respiration.

Mechanical harvest increased loss of fresh mass during cold storage, decreased fruit firmness and induced internal browning, but affected neither respiration nor ethylene synthesis. Treatment with 1-MCP before mechanical harvest prevented adverse effects such as softening and bruising, while the same treatment after mechanical harvest was less effective, indicating the benefit of a tree treatment. Manually picked, 1-MCP treated plums, however, benefited, in terms of fruit quality, by preventing or retarding bruising in the 4 weeks of cold storage.

Overall, these results (a) classify the European plum P. domestica L. as a climacteric fruit based o­n the large respiration and ethylene fluxes and rise during ripening, and their limited responses to 1-MCP, i.e. not as ‘suppressed climacteric’; (b) show that European plums can easily be cold-stored for 2 or 4 weeks, if plums are harvested mechanically or picked manually, respectively.