Development and Performance of A Temperature-Controlled Microwave Dryer

The present study was conducted to dry apples in a Temperature-Controlled Microwave (TCM) drier under optimum conditions. Drying durations, drying curves, color changes and drying models were analyzed. Within the scope of this study, TCM drying, oven drying, shade and sun-drying methods were experimented. Apples were sliced into four and eight pieces and dried at ۵۰, ۶۰ and ۷۰°C drying temperatures in three replicates. The shortest drying time (۳۰ minutes) was achieved in temperature-controlled microwave drying and the longest drying time (۲۸۷ hours) was observed in shade-drying method. TCM drying best preserved the color parameters. Lightness and redness values were best preserved with TCM drying at ۷۰°C in four slices and yellowness value was best preserved with again TCM drying at ۵۰ and ۶۰°C temperatures in four slices. Chroma values were best preserved with temperature-controlled microwave drying at ۵۰°C in eight slices. Considering the drying durations and color parameters, TCM drying was identified as the best method for drying apple.

Keywords:

Apple dryer , Color preservation , Drying curves , Drying kinetics.