Initial low oxygen stress followed by storage in controlled atmosphere of 'Royal Gala' apples

The aim of this work was to evaluate the application of initial low oxygen stress and 1-methylcyclopropene (1-MCP) on quality maintenance of Royal Gala apples, when stored in a controlled atmosphere (CA). In order to do this, a lot of 50% of the fruit was treated with 1-MCP (625 ppb) and one half of these, together with half of the fruit which did not receive the application of 1-MCP, were subjected to low oxygen stress (0.3 kPa for seven days) before being stored for seven months at 0.5 degrees C under the following CA conditions: 1.2 kPa O-2 + 2.0 kPa CO2; 1.0 kPa O-2 + 2.0 kPa CO2; 0.8 kPa O-2 + 1.0 kPa CO2; 0.6 kPa O-2 + 1.0 kPa CO2 e 0.5 kPa O-2 + 1.0 kPa CO2. After storage, and following a further seven days at 20 degrees C, analyses of fruit quality were carried out. The results show that initial low oxygen stress is not effective in maintaining quality, beyond increasing the occurrence of physiological disorders and decay. There was no big difference in the efficiency of the CA conditions used in this study on the conservation of fruit quality. The application of 1-MCP did not improve quality maintenance in fruit stored under ultralow oxygen, as seen at the lowest partial pressures (<1.0 kPa) used in this work.