Effect of controlled atmospheres containing low O2 and high CO2 on chilling susceptibility of Manila mangoes.

Disinfestation of mango (cv. Manila) was achieved by exposure to controlled atmospheres containing 1 % oxygen and either 30 or 50 % carbon dioxide for 3 days at 12 C. After disinfestation, mangoes were kept at 12 C for 27 days and transferred at regular time intervals to 25 C for ripening for up to 9 days. Weight loss, textural hardness (puncture), pH, titratable acidity, soluble solids, color and respiration rates were measured. Results were analyzed by ANOVA and Tukey's paired test (alpha=0.05). No differences were found between controlled atmosphere-treated and untreated (control) mangoes held at 12 C. However, mangoes stored at 12 C showed differences in changes in color, texture, weight loss, titratable acidity, pH and soluble solids compared to control fruits maintained at 25 C, but reached normal levels after allowed to ripen at 25 C. Respiratory activity of mangoes held at 12 C for 18 days and then allowed to ripen at 25 C was higher than that of fruits kept at 25 C. Symptoms of chilling injury appeared by 18 days in mangoes that were treated with 50 % CO2, by 21 days in mangoes treated with 30 % CO2 and by 24 days in untreated control fruits. It appeared that disinfestation by controlled atmospheres increased slightly the susceptibility of Manila mangoes to chilling injury.