Low oxygen treatment prior to cold storage to maintain the quality of apples at industrial scale

A great proportion of losses in apple production can be attributed to fruit physiological disorders, usually revealed during cold storage. These losses are commonly associated with metabolic processes in which calcium is involved. After years of study and experimentation in an attempt to reduce the incidence of Ca-related disorders by exogenous calcium treatments, a study published by Edna Pesis in 2007 opened another research route in this regard. This study, in 'Granny Smith', revealed that applying a treatment of low oxygen at room temperature, a considerable reduction of scald was achieved and pointed to a possible effect on alleviating bitter pit. It was hypothesized that low oxygen treatments may delay the metabolic activity of fruits and also delay ripening, softening and withering. Since 2008, we have continued to deepen into the development of alternative methods of low environmental impact which avoid the use of chemicals. Strategies have been developed for the application of LOT (low oxygen treatment) treatments at room temperature in various apple cultivars, obtaining promising results at the lab and at the semi-industrial scale. In this paper, LOT technology has been validated, this time, on an industrial scale. An Ilerfred system, with monitoring and control of CO₂ and O₂, was used. The LOT followed by conventional cold storage has proved to be very effective for the control of rots in all cultivars, and was able to effectively control “lenticel blotch pit” in 'Reinette'. The results of the 2016 campaign compared to those of the two previous seasons allow us to conclude that improvement in shelf life of apples is achieved by combining different LOT conditions with the dynamic controlled atmosphere (DCA) storage technology.