Abstract

The optimum condition for storage of 'Laetitia' plums (Prunus salicina) under controlled atmosphere (CA) is not currently known. This study was aimed at assessing the effects of controlled atmospheric (CA) conditions on the postharvest quality preservation of ‘Laetitia’ plums. Besides regular atmosphere  (RA; 21kPa O₂ + 0.03 kPa CO₂) as condition/treatment control, the following CA conditions (kPa O₂ + kPa CO₂) were assessed: 1+3; 1+5; 2+5; 2+10; and 11+10. In all cases, the fruit were stored for 60 days at 0.5°C±0.1°C and 96±2% of relative humidity (RH). Upon removal from the cold storage chamber and after four days in ambient conditions (20±2°C/60±5% RH), the fruit were assessed in terms of: respiration and ethylene production rates; flesh firmness; texture; titrable acidity; red color index and hue angle (h^o) of the skin; incidence of fruit cracking and internal breakdown (flesh browning). The fruit stored under the different CA conditions presented lower respiration and ethylene production rates, higher values of flesh firmness, texture and titrable acidity, lower development of skin red color, and lower incidence of skin cracking compared to the fruit under RA. CA conditions of 2+5, 1+5, and 1+3 resulted in a more substantial delay of ripening. CA conditions of 2+5 and 1+3 resulted in lower incidence of internal breakdown.

Key words: Ripening, physiological disorder, postharvest, Prunus salicina.