Feasibility of ambient loading of citrus fruit into refrigerated containers for cooling during marine transport

Abstract

As an alternative to forced-air precooling, warm loading of citrus fruit into refrigerated containers for cooling during marine transport was explored. This practice could provide several logistic and economic savings. Although successful for resilient citrus fruits, the cooling process and performance of ambient loading have not been explored in a systematic manner. There is still a considerable potential to optimise the implementation of the technique and to apply it to more sensitive citrus or other fruits. Calculations identified the required cooling capacity of a refrigerated container as a function of the envisaged fruit cooling time, and these were complemented by a full-scale experiment. Although a refrigerated container was theoretically able to cool the produce in less than 5 days, the experiment showed that these cooling rates are not currently achieved in practice, bearing in mind that step-down cooling was applied. Future improvements in the technique point towards an improved box design and better stacking on the pallet, and to reducing airflow short-circuits between pallets.