Abstract

A microwave (MW) drying system was built for drying skipjack tuna. It was composed of waveguide and cavity, and a modification to the high-voltage power supply using a power electronic device to control the phase of AC input voltage to a high-voltage transformer. The calibration of the MW power enables tuning the power to be used for drying skipjack tuna. The experimental set-up was studied drying kinetics: time profiles of temperature and moisture content (%MC). The temperature was measured using a thermopile thermometer, which was connected to the microcontroller and the PC via an RS232 port. The %MC was monitored gravimetrically. The experimental results and the simulation results from finite element method computations were compared by assessing the coefficient of determination (R ²) and the root-mean-square-error (RMSE). Finally, empirical and semi-theoretical models were fit to the experimental results of moisture ratio and evaluated for best fit using R ² and RMSE.