Responses of ‘Fuji’ apples to short and long duration exposure to elevated CO2 concentration

Fruit maturity, diphenylamine (DPA) treatment and controlled atmosphere (CA) storage regimes were evaluated as factors affecting development of ‘Fuji’ apple CO2 injury. The incidence and severity of CO2 injury (brown-heart) increased with advanced maturity and greater watercore severity at harvest. The development of CO2 injury during storage was prevented by DPA treatment. The severity of CO2 injury was higher in fruit exposed to 20 kPa CO2 after harvest than in fruit exposed to 20 kPa CO2 after 8 months of CA storage. Ethanol, acetaldehyde and methanol concentrations increased during shortand long-term exposure to high CO2, however, DPA reduced ethanol and acetaldehyde accumulation. Storage in low O2 (0.5 kPa O2, 0.05 kPa CO2) also stimulated accumulation of ethanol, acetaldehyde and methanol however, no internal disorders developed with or without the use of DPA. The harvest date effect on severity of CO2-injury following short-term exposure to 20 kPa CO2 was related to severity of CO2-injury after long-term CA storage with 3 kPa CO2. © 2002 Elsevier Science B.V. All rights reserved.