The storage of fruit at minimum oxygen condition is crucial for optimal fruit quality maintenance. However, the optimal oxygen partial pressure of fruit varies according to several factors such as species, cultivar, harvest maturity, temperature, growing season and storage period. Based on these factors, storage technologies were developed that allow for the detection of the lower oxygen limit (LOL) and the storage of fruit under the lowest optimal oxygen partial pressure. One emerging technology is known as dynamic controlled atmosphere (DCA). Commercially, there are four DCA systems used: [1] DCA based on ethanol production and accumulation (DCA-Eth); [2] DCA based on chlorophyll fluorescence (DCA-CF); DCA based on the respiratory quotient (DCA-RQ) and [4] DCA based solely on CO2 production (DCA-CD). This reviews the recent developments of these DCA systems and their effect on fruit quality. Generally, the storage of fruit under DCA has a positive effect on the overall fruit quality, with regards to reduced physiological disorders and higher flesh firmness maintenance, when compared to controlled atmosphere (CA). Evidence also shows that storing fruit under DCA-RQ and DCA-CD allowed higher volatile compound emission and concentration, which can contribute positively to fruit flavor. The DCA systems are “green storage technologies” because the system enables the increase of storage temperature and thereby saving electrical energy. Storage of apples under DCA maintains an overall fruit quality similar to CA combined with the ripening inhibitor 1-Methylcyclopropen (1-MCP), which is an interesting option for organic fruit storage. Dynamic controlled atmosphere is a recently developed storage technique and is in constant improvement. The latest developed DCA techniques (DCA-RQ and DCA-CD), in contrast to DCA-CF, allow the use of extremely low oxygen levels. In the future, new and multi-sensor DCA systems are under development, which might not just control O2 partial pressure but also temperature and other parameters to allow for more energy efficient but high quality fruit storage systems.

This study was carried out to examine the response of ‘Luiza’ apple to different storage atmospheres, durations, and chemical inhibition of ethylene action by 1-MCP. Analysis of fruit quality and physiological disorder incidence were performed every two months during eight months of storage for Exp. 1 and 2, and after eight months for Exp. 3. Both CA storage and 1-MCP treatment reduced fruit ethylene production and respiration and prevented the rapid fruit softening, flesh browning incidence and fungal decay of ‘Luiza’ apple. The combination of 1-MCP treatment before storage in CA provided an additional benefit in firmness retention after simulated marketing conditions at 22oC. Based on the time to reach a firmness of 53 N, the storage life of ‘Luiza’ apple is less than four months in air-storage and more than six months under CA-storage. ‘Luiza’ fruit did not develop symptoms of CO2 injury when stored under high CO2 partial pressures (up to 4.5 kPa). However, we observed increased flesh browning and fungal decay incidence for CA-stored fruit between six and eight months of storage. Therefore, the storage potential of ‘Luiza’ apple fruit may be limited to six months under CA-storage (1.5 kPa O2 and 2.5 kPa CO2).