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 50, 60 and 70°C drying temperatures in three replicates. The shortest drying time (30 minutes) was achieved in temperature-controlled microwave drying and the longest drying time (287 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 70°C in four slices and yellowness value was best preserved with again TCM drying at 50 and 60°C temperatures in four slices. Chroma values were best preserved with temperature-controlled microwave drying at 50°C in eight slices. Considering the drying durations and color parameters, TCM drying was identified as the best method for drying apple.