A comparative study between intermittent microwave and infrared drying of bioproducts

Abstract

A systematic experimental study of both intermittent microwave (MW) and infrared (IR) drying was used to compare the efficacy of the two methods when batch drying two bioproducts, namely potato and carrot. The controllable parameters examined in this study were MW power and IR intensity level, MW and IR intermittencies and the transition period from convective to MW drying. A comparison of the drying kinetics showed intermittent MW drying to be an effective method for shortening the drying time that was required to reach a certain moisture content when it was compared with intermittent IR drying and convective-MW drying. A comparison of the colour degradation of the product showed that step variation of the IR intensity during intermittent drying reduced the colour change of the product less than constant radiative intermittent IR drying.