CHILLING INJURY IN CANTALOUPE MELONS AT TWO MATURITY STAGES

Abstract

Inf this work we evaluated physiological responses in ripe and unripe cantaloupe melons related to chilling injury (CI) symptoms. Weight loss, firmness, pH, tritatable acidity, total soluble solid, color, electrolyte leakage, ethanol and acetaldehyde accumulation, and respiration and ethylene production rates were monitored on ripe and unripe fruits. Chilling injury in both maturation stages showed similar symptoms, but these appeared at different periods. CI symptoms found in epicarp were mainly pitting, then turning into brown discoloration and finally depressed areas. This produced watery zones in the mesocarp. Unripe fruits were more susceptible to CI that ripe melons. When stored at 2°C they displayed the highest CI damage after 13 d, while ripe fruits developed similar symptoms but only after 30 d. CI caused textural firmness reduction, and both acetaldehyde and ethanol accumulation. Severity of chilling injury in both ripe and unripe stages was correlated with physiological weight loss, ethylene production rate and textural firmness reduction. CI in unripe fruits was correlated with acetaldehyde accumulation, although in ripe fruits correlated with respiration rate. We concluded that ripe melons can tolerate low storage better than unripe melons. Additionally, maturity index is a key factor to determine the severity of chilling injury symptoms.