Drying Kinetics of Air Fryer Roasted Sesame Seeds: Mathematical and Neural Networks Modeling

Abstract

Roasting is the essential preliminary step in the production of sesame paste. In this study, the effect of air-fryer temperatures (170°C, 180°C, and 190°C) on the drying kinetics of sesame seeds was investigated as an innovative process in roasting. The drying kinetics of the thin layer model were studied, and the effective moisture diffusivity was evaluated using Fick's equation of diffusion. The thermodynamic parameters of the process were also established, including the enthalpy (ΔH), entropy (ΔS), and Gibbs free energy (ΔG). Additionally, the drying behavior of the samples was predicted by applying artificial neural network (ANN) methods. In conclusion, the Midilli et al. model was the one that best fitted the observed data, which represents the drying process. As the temperature increased, the D_eff value of sesame seeds demonstrated a significant increase from 1.49 to 1.78 × 10⁻⁷ m²/s. The activation energy (E_a) of sesame seeds was found to be 14.77 kJ/mol. As the drying temperature increased, the Gibbs free energy increased, and the enthalpy decreased. There was no effect of temperature on the negative entropy value (−0.345 kJ/mol K). The ANN model was able to predict the moisture content during the roasting process with an accuracy of 99.96%. Therefore, air frying could be recommended as an energy-efficient and promising approach to roasting sesame seeds.