Effects of deviations in airflow properties and product properties on cooling of chicory roots were studied based on numerical simulations with a validated transient model of coupled heat and mass transfer in bulks of chicory roots. The model was solved for a one-dimension 1-m deep bulk of chicory roots cooled at various levels of air velocity, temperature and relative humidity. Variations in bulk porosity, heat of respiration and product heat capacity were studied as well. The results led to an improved understanding of the cooling process with respect to control strategies and cold store practice. The smallest sensitivity of product temperature with respect to process conditions was found at low velocity (0.1 m s(-1)), low temperature (1 degreesC) and high RH (95%). Small deviations of these conditions could, however, still lead to increased weight losses by as much as 4% after 3 months of storage. Variations of bulk porosity and of respiration rates significantly affected weight loss variations. (C) 2003 Elsevier Ltd. All rights reserved.