EFFECTS OF CARBON DIOXIDE TREATMENT ON CONTROLLED ATMOSPHERE STORAGE BEHAVIOR OF McINTOSH APPLES

McIntosh apples (Malus sylvestris Mill.) were treated with different levels of CO2 for various lengths of time prior to controlled atmosphere storage. Beneficial effects of CO2 treatment on retardation of softening were observed in 1973 and in a commercial trial in 1974, but not in the 1974 and 1975 experiments. There was no effect of CO2 treatment on soluble solids or acid levels. Extensive surface and internal injury was found in apples treated with 15 or 20% CO2 for 10 or more days. In the limited commercial trial, CO2-treated fruit was significantly firmer than untreated fruit, but the difference in firmness was not considered sufficient to warrant application of the treatment for McIntosh apples.