Temperature Variation During Dynamic Controlled Atmosphere Storage: Effects on the Quality of ‘Maxi Gala’ Apples

This study aimed to determine the temperature variation strategies in the first 30 days in dynamic controlled atmosphere storage based on respiratory quotient 1.3 (DCA-RQ 1.3) on the quality maintenance of ‘Maxi Gala’ apples after long-term storage plus extended shelf life (7 and 14 days). ‘Maxi Gala’ apples were harvested in two growing seasons, in 2019 (first season) and 2020 (second season). ‘Maxi Gala’ apples were stored under a controlled atmosphere with ultra-low oxygen (CA/ULO), CA/ULO + 1‑methylcyclopropene (CA/ULO + 1‑MCP) at 2.0 °C in the two growing seasons, and DCA-RQ 1.3 under constant temperatures of 0.5, 2.0 (first season), 1.0, and 2.5 °C (second season) and temperature variation strategies of (0.5 → 2.0), (2.0 → 0.5) in 2019, and in 2020 of (1.0 → 2.5) and (2.5 → 1.0) °C. Fruit stored under DCA-RQ 1.3 with constant temperatures of 2.0 and 2.5 °C and temperature variation of (2.0 → 0.5) and (1.0 → 2.5) °C showed high flesh firmness and the highest healthy fruit amount due to the lowest mealiness and flesh breakdown incidence compared to CA/ULO and CA/ULO + 1‑MCP after 7 and 14 days shelf life. Fruit stored under DCA-RQ 1.3 at 1.0 °C showed lower flesh firmness and healthy fruit amount due to highest mealiness, flesh breakdown, and decay after 7 and 14 days at 20 °C. In conclusion, DCA-RQ 1.3 at 2.0 and 2.5 °C keeps fruit with high physicochemical quality for long-term storage, prolonging shelf life for up to 14 days at 20 °C. Temperature variation strategies do not provide additional benefits to physicochemical quality compared to constant temperature (2.0–2.5 °C).