Little is known about the thermophysical properties of fresh-cut lettuce other than heat of respiration. Empirical correlations based on food composition remain the only way to estimate the thermophysical properties of fresh-cut lettuce. The objectives of this study were (i) to determine the thermophysical properties of several baby-leaf lettuce and brassica greens and (ii) to verify the measured thermophysical properties by using them in a heat transfer model and comparing the predicted product temperatures with measured product temperatures in a simulated interruption of a cold chain. Density, leaf thickness, thermal conductivity, specific heat and water activity from nine varieties of baby-leaf lettuce and brassica greens were measured. A broken cold chain was simulated in a low temperature incubator set at 10 degrees C for a length of time before readjustment at 2 degrees C. Results showed that density (1078-1112 kg m(-3)), leaf thickness (0.18-0.54 mm), thermal conductivity (0.55-0.70 W (m degrees C)(-1)) and specific heat (3.1-4.3 kJ (kg degrees C)(-1)) varied significantly (P < 0.05) between varieties. However, no significant differences were observed for water activity (0.959 +/- 0.006). Using thermophysical properties as input in the heat transfer model, experimental and calculated temperatures were well correlated (R-2 = 0.98) with a root mean square error of 0.57 degrees C over the 10-40 mg CO2 (kg h)(-1) range of respiration rate. The measured thermophysical properties adequately predicted the temperature of the baby-leaf greens during simulated broken cold chains. A sensitivity analysis performed with the heat transfer model showed that the thermal conductivity, the specific heat and the density were relatively more important on the thermal behaviour of the baby-leaf greens than the heat of respiration. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.