Effect of Calcium Infiltration on Ethylene Production, Respiration Rate, Soluble Polyuronide Content, and Quality of ‘Golden Delicious’ Apple Fruit

Fruit of ‘Golden Delicious’ apple ( Malus domestica Borkh.) infiltrated after harvest with CaCl 2 solutions of up to 12% (w/v) had lower ethylene production rates than untreated fruit during a 7-day period at 20°C immediately following treatment. However, after a 5-month storage period at 0° the effect of calcium on ethylene production diminished rapidly during a 7-day ripening period at 20°. Ethylene production for the 7-day period immediately following calcium treatment was correlated negatively to calcium concentration of the fruit. Calcium treatment had no significant effect on fruit respiration rate in this study. High calcium concentrations resulted in a decrease in the magnitude of ethylene production but had no effect on respiration. Titratable acidity and percentage of soluble solids were unaffected by calcium treatment even at high concentrations of CaCl 2 . Fruit firmness was correlated positively to calcium concentration of the fruit both before and after storage at 0°, and soluble polyuronide content of the fruit was correlated negatively to fruit calcium.