RQ-Based Dynamic Controlled Atmosphere Storage of Apple Fruit

“Golden Delicious” apples (Malus ×domestica Borkh. ‘Golden Delicious’) were stored with regular CA, regular CA after treatment with the ethylene receptor blocker 1-MCP (SmartFreshSM) (regular CA + 1-MCP), RQ-DCA and RQ-DCA after treatment with 1-MCP (RQ-DCA + 1-MCP). Post-storage effects on fruit quality immediately after storage as well as during subsequent shelf life at 18 °C were investigated and compared for the different storage treatments. Quality attributes evaluated were Magness-Taylor firmness, background color (hue angle) and internal ethanol content. The RQ-DCA control system was able to control O2 and CO2 partial pressures in the storage container automatically, without human intervention. The RQ, breakpoint of the RQ-DCA stored fruit was found to be 0.2 kPa O2. RQ-DCA was shown to have a significant effect on post-storage quality. The firmness and color of RQ-DCA stored fruit were found to be significantly higher compared to those of fruit stored with regular CA and were comparable to those of fruit stored with RQ-DCA and regular CA after treatment with 1-MCP. Internal ethanol concentrations in the fruit juice were found to be very low, indicating the RQ-DCA control system could detect low oxygen stress accurately before fermentation was triggered and ethanol could accumulate in the fruit.status: accepte