MODELING OF MASS TRANSFER PARAMETERS DURING DEEP-FAT FRYING OF FRIED MELON CAKE (ROBO)

In this investigation, the mechanism of mass (moisture and fat) transfer during deep-fat frying of robo (fried melon cake) was carried out. The plots of dimensionless concentration ratios against time were used to determine moisture transfer parameters including moisture diffusivity, moisture transfer coefficient, moisture transfer Fourier number, moisture transfer Biot number and activation energy and fat transfer kinetic parameters such rate constants and activation energy at different frying temperatures of 140, 155 and 170 0C. All moisture parameters increased linearly with frying oil temperatures except moisture transfer Biot number which deceased linearly with increase in temperature with correlation coefficient (R2) ≥ 0.99. There was also positive linear relationship between fat transfer rate constant and frying temperatures (R2 ≥ 0.99). An Arrhenius type of relationship was found between temperature and the effective moisture diffusivity and fat transfer rate constant (R2≥0.99) with activation energies values calculated as 25.66 and 42.18 kJ/mol, respectively. Both moisture loss and fat desorption after initial adsorption of 60 seconds were adequately modeled by the first-order kinetics adopted with high correlation coefficient (R2) value and were time and temperature dependent as revealed by Arrhenius analysis performed on the experimental data.