Dynamic controlled atmosphere storage suppresses metabolism and enhances volatile concentrations of 'Galaxy' apple harvested at three maturity stages

The objective of this study was to assess the interaction between four storage conditions and three maturity stages of 'Galaxy' apple at harvest (unripe, ripe and overripe, based on starch pattern index) on its metabolism and volatile concentrations after harvest and 9 months of storage plus 7 days of shelf life at 20 °C. Storage conditions were: [1] Controlled atmosphere (CA) (1.2 kPa O2 + 2.0 kPa CO2); [2] CA + 1-methylcyclopropene (1-MCP) (0.625 μL L−1); [3] Dynamic controlled atmosphere based on respiratory quotient 1.3 (DCA-RQ 1.3) + 1.2 kPa CO2 and [4] DCA-RQ 1.5 + 1.2 kPa CO2. Fruit stored under DCA-RQ 1.5 had higher concentrations of total esters and characteristic aroma volatile compounds in extracted juice. Highest ester concentrations occurred in overripe fruit stored at DCA-RQ 1.3 and DCA-RQ 1.5. 1-MCP application suppressed volatile compound production, not allowing its increment with advanced of the maturity stage and reduced the main esters after storage. DCA-RQ suppressed internal ethylene concentration, ethylene production, and respiration rate, but the low metabolism in fruit stored under DCA-RQ 1.5 did not result in lower volatile compound production.