Effect of dynamic controlled atmosphere monitored by respiratory quotient and 1-methylcyclopropene on the metabolism and quality of 'Galaxy' apple harvested at three maturity stages

- DCA-RQ is efficient in quality maintenance regardless maturity at harvest.
- DCA-RQ 1.3 maintain similar quality as compared to 1-MCP treatment.
- The anaerobic metabolism change among maturity stages.
- DCA-RQ 1.5 result in higher fermentation without increase electrolyte leakage.

The objective of this study was to evaluate the interaction between controlled atmosphere (CA), CA + 1-methylcyclopropene (1-MCP) and dynamic controlled atmosphere monitored by respiratory quotient (DCA-RQ) with three fruit maturity stages at harvest (early harvest date, optimal harvest date and late harvest date) on 'Galaxy' apple metabolism and quality after harvest and 9 months storage plus 7 days of shelf life at 20 °C. Fruit stored under dynamic controlled atmosphere monitored by respiratory quotient 1.3 (DCA-RQ 1.3) showed lower ethylene production, respiration rate, mealiness and higher flesh firmness in comparison to CA stored fruit, but did not differ from those treated with 1-MCP. The dynamic controlled atmosphere monitored by respiratory quotient 1.5 (DCA-RQ 1.5) increased the acetaldehyde, ethanol and ethyl acetate concentration, regardless of the fruit maturity at harvest. The storage of 'Galaxy' apple under DCA-RQ 1.3 is efficient in keeping quality regardless of the maturity stage at harvest.