KINETICS AND THERMODYNAMIC PROPERTIES OF PARBOILED BURGOS WHEAT (TRITICUM DURUM) IN TURKEY DURING DRYING

İngilizce (OpenAlex)

The influence of temperature and dryer types on kinetics, thermodynamic properties of parboiled wheat (bulgur) in Turkey was studied during drying.Durum wheat (local name in Turkey, Burgos) was cooked under atmospheric conditions, and then it was dried at 50, 60 and 70 °C.Six semitheoretical and Fick's diffusivity models with Arrhenius and Eyring-Polanyi approaches were employed to predict drying kinetics and thermodynamic properties.Among all the models, Midilli model was found to have the best fit as suggested average R 2 value of 0.9987, and corresponding RMSE value of 0.010.Effective diffusion coefficient (D eff ) increased significantly (P ≤ 0.05) from 2.38×10 -11 to 5.84×10 -11 (59% increase), 4.65×10 -11 to 8.51×10 -11 (45% increase), and 8.70×10 -11 to 14.10×10 -11 (38% increase) for natural convective air, forced convective air and vacuum drying systems with temperature increase from 50 to 70 °C.The activation energy values of the samples of natural convective air drying (NCAD) (41.46 kJ mol -1 ) compared with that of forced convective air drying (FCAD) (27.71 kJ mol -1 ) and vacuum drying (VD) (22.28 kJ mol -1 ) show a decrease trend which suggests more effective drying.The enthalpy and entropy decreased with increasing temperature for all dryers.The Gibbs free energy increased with increasing temperature.For each dryer, also, general equations to describe the moisture ratio of parboiled wheat as a function of time and temperature were developed.It was concluded that vacuum dryer has provided more effective drying than the other dryers.