Kinetic Modeling of Heat and Mass Transfer During Deep Fat Frying of Churro

Abstract

The effect of deep fat frying temperatures, ranging from 160 to 190 oC, on frying parameters including the heat transfer coefficient (he), mass transfer coefficient (ke) and effective moisture diffusivity (De) were investigated during deep fat frying of churro that is fried dough pastry. Therefore experimental studies were conducted for both heat and mass transfer phenomena and mathematical model was developed for simultaneous transfer by using Newman technique for churro actual geometry (3-D cylindrical shape). Fourier’s and Fick’s laws were applied for computation of coefficients of heat and mass transfer. The he coefficients were 437.360-93.535 W/m2K in the temperatures range of 160 to 190 oC. However, the value of ke and De increased by an increase in oil temperature during frying. The maximum values were determined as 17.36 x10-5 m/s and 2.48 x10-5 m2/s at 190 oC for ke and De, respectively. Model and experimental data had good agreement and the transfer coefficients followed the first order kinetic model with high R2 and low RMSE values. There was found an Arrhenius equation between the effective moisture diffusivity and deep fat frying temperature, so the value of activation energy was calculated as 63.546 kj/mol.