VARIABLE OXYGEN AND CARBON DIOXIDE CONCENTRATIONS DURING CONTROLLED ATMOSPHERE STORAGE OF `GOLDEN DELICIOUS' APPLES
In both experiments. 20-apple samples from 6 commercial orchards were harvested and stored in 208 liter containers at 0C for 4, 6, and 8 months. Additional samples were removed from CA and held at 0C for 14 days before evaluation. Gas composition was measured and controlled 6 times per day using automatic control equipment. In the first experiment, samples were stored at constant 0.0% CO2 and one of three O2 regimes (constant 2.0%. 0.5 rising to 3.5%. or 3.5% falling to 0.5% O2). Apples stored at 3.5% falling to 0.5% O2 during the storage period were softer than apples held at constant 2.0% or those held at 0.5% rising to 3.5% O2 during the storage period. Variable O2 concentrations did not influence weight loss during storage and insignificant scald, flesh browning, core browning, rot, and low 02 injury were observed. In the second experiment, samples were stored at constant 2.0% O2 and one of three CO2 regimes (constant 0%, constant 5%. or 0% rising to 6% CO2). Constant 5% or rising CO2 conditions did not significantly influence flesh softening or weight loss during storage. Negligible CO2 injury was observed.