Elevated CO2 in dynamic controlled atmosphere storage: Impact on anaerobic metabolism and overall quality of 'Maxi Gala' apples.

BACKGROUND

The present study investigated the effects of high CO2 partial pressures (pCO2) in dynamic controlled atmosphere monitored by respiratory quotient (DCA-RQ 1.3) on the anaerobic metabolism compounds, physiological disorders and overall quality of 'Maxi Gala' apples after 9 months of storage (2.0 °C), plus 7 days of shelf life (20 °C). Two experiments were conducted over 2 years. In the first year, 'Maxi Gala' apples were stored under controlled atmosphere (CA - 1.2 kPa O2 + 2.0 kPa CO2), CA + 1-methylcyclopropene (1-MCP), DCA by chlorophyll fluorescence (DCA-CF + 1.2 kPa CO2) and DCA-RQ 1.3 with different pCO2 (0.4, 1.2, and 1.6). The same treatments were evaluated in the second year, with addition of DCA-RQ 1.3 + 2.0 kPa CO2.

RESULTS

'Maxi Gala' apple stored under DCA-RQ 1.3 + 0.4 kPa CO2 and DCA-CF maintained healthy fruit amount similar to DCA-RQ 1.3 + 1.2 and 1.6 kPa CO2, but with lower flesh firmness. DCA-RQ 1.3 with higher pCO2 (1.6 or 2.0) increases the production of ethyl acetate, but did not impact physiological disorders compared to DCA-CF. CA + 1-MCP maintained high flesh firmness, but reduced healthy fruit amount.

CONCLUSION

The present study has demonstrated that DCA-RQ 1.3 with 1.6 or 2.0 pCO2 can be adopted for 'Maxi Gala' apples storage, resulting in similar or better fruit quality than DCA-RQ 1.3 + 1.2 kPa CO2. Additionally, the adoption of high pCO2 in the DCA-RQ storage system can result in cost reductions related to CO2 adsorption. © 2024 Society of Chemical Industry.