Abstract:The objective of this study was to develop a heat transfer model for gas grilling of salmon steaks and evaluate the inactivation behavior of Listeria monocytogenes under different grilling conditions by incorporating microbial thermal inactivation kinetics. The one-dimensional unsteady heat transfer model was used to describe the heat transfer process during gas grilling of salmon, and the model parameters were solved by the combination of the finite difference method and least square optimization algorithm, then the temperature history during gas grilling was also obtained. Finally, the lethality of Listeria monocytogenes during gas grilling was calculated by the General Method. The results showed that the thermal diffusion coefficient, convective heat transfer coefficient of flame side and air side were 1.83 × 10-7 m/s2, 15.18 W/(m2·℃) and 16.36 W/(m2·℃), respectively. Verification tests showed that the developed model can be suitable for describing the heat transfer during gas grilling of salmon, with the RMSE of 1.48-3.33 ℃ between the model predictions and the measured values. In addition, numerical simulation of different scenario showed that Listeria monocytogenes could still survive in salmon steaks if they were unevenly turned during the roasting process, even if the center temperature up to 71 ℃, however, if they were flipped evenly with the time interval of 2, 3, 4 min or 5 min during gas grilling, the lethality of Listeria monocytogenes at all locations was greater than 5.21 lg(CFU/g) when the center temperature of the salmon steak reached 71 ℃. The results of this study can provide scientific guidance for safe cooking.