Modeling of mass and heat transfer in deep fat frying processes and evaluation in potato model food system

In the present study, a convective heat transfer coefficientchanges during deep fat frying was investigated. So, by keeping the oil temperature constant as a heat transfer medium, temperature changes in a potato strip (cube-shaped), in the center and left-right sides of the strip during frying by a three-channel thermocouple was measured. Processing temperature of oil was 150, 160 and 170°C. The strip temperature was recorded by a data logger at     ten-second intervals. Due to no significant changes in the temperature of different selected locations in potato strip, the center temperature was selected and recorded as an effective temperature. Also, heat transfer parameter included convective coefficient () was calculated in the range of 128_515 W/m2.K .Result showed that  is high in high levels temperature because of increasing rate of moisture exiting and turbulence in the oil. Also, with increasing oil temperature, decreasing of oil content and decreasing in moisture content of slices were observed. The mass transfer parameters including the effective moisture diffusivity () and the oil diffusivity () were calculated in the range of 9.12×10-9 _1.31×10-8 m2/s and  1.26×10-5_1.52×10-5 m2/s , respectively. By using the calculated coefficients, heat and mass transfer modeling, was done by mathematical equations and the relevant equations were solved by the method of separation variables. Simulation was also done with COMSOL Multiphysics version 5.3a and the resulted profiles were also presented.