EFFECT OF LOW-OXYGEN ATMOSPHERE ON STORAGE SCALD AND QUALITY PRESERVATION OF DELICIOUS APPLES

Studies of low-O2 storage of ''Delicious'' apple fruit (M. domestica Borkh.) were conducted in Oregon [USA] (1981), Washington (1982) and British Columbia [Canada] (1981 and 1982). A combination of 1% O2 with 1% CO2 was the most promising for control of storage scald and quality preservation of ''Delicious'' apple fruit grown in Oregon. A combination of 1% O2 with < 0.03% CO2 effectively reduced or eliminated the incidence of storage scald and preserved dessert quality of apples grown in Washington. Early-harvested apples from British Columbia developed a high incidence of storage scald after 7 mo. of storage in 1% O2 with 0.05% CO2. Apples harvested at commercial maturity, developed only slight or minimal storage scald symptom after 7 mo. of storage in 1 and 0.5% O2 with 0.05% CO2. A high incidence of low-O2 injury (i.e., ribbon-like, depressed skin browning) was found in fruit from Oregon stored for 9 mo. in 0.5% O2 (with or without CO2) and in 1.0% to 1.5% O2 with < 0.03% CO2. No low-O2 injury was found in fruit from Washington or British Columbia after low-O2 storage.