Numerical analysis of coupled heat and mass transfer processes in packaged tomatoes throughout the cold chain

This study simulated the heat- and mass-transfer characteristics of fresh tomatoes by developing a computational fluid dynamics model. The root-mean-square error (RMSE) and mean absolute percentage error (MAPE) for the tomato temperature were 0.579 °C and 3.89%, respectively, and the RMSE and MAPE for the tomato mass loss were 0.737 g and 9.87%, respectively. Furthermore, the effect of different cold chain breaking (CCB) parameters on fluctuations in tomato temperature and mass loss were quantified by a sensitivity analysis. The results indicate that CCB increases the tomato temperature and moisture loss compared with an uninterrupted cold chain, especially for the tomato moisture loss during the second CCB because of the irreversibility and superposition of this negative effect. Furthermore, CCB would increase the inhomogeneity of the temperature distribution of packaged tomatoes but significantly reduce the inhomogeneity of tomato mass loss. Additionally, tomato temperature fluctuations are less sensitive to changes in relative humidity during the CCB process, and the sensitivity between them is almost two orders of magnitude less than the sensitivity of other CCB parameters. However, the loss of tomato mass proved to depend most strongly on variations in relative humidity and the least on variations in the CCB temperature.