Effects of pressure level
The drying rates of the durian chips dried by MWVC under a pressure of 10 kPa were higher than those dried under 30 kPa at all microwave power levels (see Fig. 3).This is because, at lower pressure, water boils more easily at a lower saturated temperature (Hu et al., 2006; Swasdisevi et al., 2009); there-fore more moisture vapour developed inside the durian flesh, resulting in a high mass transfer rate.