Forced-convective cooling of citrus fruit: Package design

Optimisation of package design for citrus fruit is required to increase the throughput, by reducing the precooling time, and to enhance fruit quality by providing fast and uniform cooling without inducing chilling injury. The cooling performance of an existing container and of two new containers (Supervent and Ecopack), as stacked on a pallet, was evaluated experimentally and numerically with computational fluid dynamics (CFD). The accuracy of the CFD simulations was confirmed by a good agreement with experiments. The best cooling performance was found for Ecopack, but removing airflow short circuits in this container may enhance the cooling performance even more. Also with respect to uniformity of cooling of the fruit and the magnitude of the convective heat transfer coefficients, in a specific container and between different containers on the pallet, the Ecopack container performed best, followed by the Supervent and the standard container. The new container designs thus clearly showed significant improvements in cooling performance.