Energy and exergy analyses in microwave drying of orange slices

The orange samples were cut into slices with a thickness of 4 mm and treated with ohmic method for 3, 5, and 7 min as ohmic pre-treatment in three voltages 30, 50 and 70 V. Then, they were dried in three replicates using a microwave dryer and at three powers of 90, 360, and 900 W. The statistical analysis results showed that the ohmic time, ohmic voltage and microwave power are significant for the energy and exergy efficiency and specific energy and exergy loss at 1% level. The highest energy and exergy efficiency was observed at 900 W and in the ohmic time of 7 min. The highest energy and exergy efficiency was observed at 59.041% and 47.76%, respectively. The maximum energy loss was seen at 90 W and ohmic time of 3 min. The microwave power, ohmic time, and ohmic voltage were statistically significant for all the parameters (energy and exergy) such that with increasing them, the energy and exergy efficiency increased, while the specific exergy and energy loss decreased.