Delaying establishment of controlled atmosphere or CO2 exposure reduces ‘Fuji’ apple CO2 injury without excessive fruit quality loss

Abstract

Abstract Storage of ‘Fuji’ apple fruit in a high CO 2 (3 kPa) and low O 2 (1.5 kPa) controlled atmosphere (CA) reduced firmness and titratable acidity (TA) loss during long term storage. This CA environment also induced development of internal CO 2 -injury (brown-heart) and slowed the disappearance of watercore. The symptoms of internal CO 2 -injury were first detected 15 days after CA establishment and the severity increased during the first 4 months of CA-storage. Delaying establishment of CA conditions for 2–12 weeks significantly reduced the severity of CO 2 -injury. Delaying CO 2 accumulation to 3 kPa for 1–4 months during CA (1.5 kPa O 2 +0.05 kPa CO 2 ) storage also reduced development of CO 2 -injury symptoms. Delaying CA or CO 2 accumulation resulted in lower firmness and TA compared to establishment of CA within 72 h of harvest. However, the delay treatments did result in firmness and TA that were significantly higher compared to values for fruit stored in air. The incidence and severity of senescent injuries (flesh browning and core flush) detected during the late period of storage were greater in air- than CA-stored fruit. The results indicate the susceptibility of ‘Fuji’ apples to CO 2 -injury is highest during the first weeks of storage after harvest. Delaying establishment of CA or exposure to elevated CO 2 after harvest may be a practical strategy to reduce CO 2 -injury while maintaining other important quality attributes at acceptable levels.