Background: Frying is the cooking of food in fat, which involves heat and mass transfer simultaneously. During frying, moisture loss creates cavities or pores as well as passageways in the food. These cavities are known as capillary pores and the oil penetrates through them during frying. 
Materials and Methods: This study aimed to evaluate the effect of chitosan on mass transfer during deep-fat frying of Kurdish cheese nuggets. Moreover, the effect of chitosan level (0, 0.5, and 1.5%), frying temperature (150, 170, and 190°C), and frying time (0, 1, 2, 3, and 4 min) on mass transfer in the breading coating and the core parts were determined in this study. The data were statistically analyzed using ANOVA and Duncan post-hoc test in SPSS software (Version 21.0). In addition, MATLAB software was utilized to fit the equations. 
Results: The results showed an interaction effect of these processing conditions on mass transfer. Batter- coated samples with 1.5% chitosan had the lowest oil content in core and breading among all formulations. The model based on Fick’s law was used to describe moisture transfer data. The oil absorption rate constants in the breading and core parts were within the range of 0.19-0.27 s−1- 0.22-0.41 s−1, respectively. Activation energy obtained from the Arrhenius plot ranged between 13.65 and 54.93 kJ/mol.
Conclusions: Moisture loss during frying increased with the increase of frying time and temperature and was significantly affected by batter formulation. The kinetic models gave a good fit for moisture diffusion and oil transfer.