he percent yield of lavender EO was obtained at four different times (5, 15, 30 and 60 min) using the coaxial MWHD extraction approach, and at 180 min using conventional HD. Fig. 2(a) shows the kinetics of lavender EO extraction using the coaxial MWHD approach. The percent yield (w/w) showed a strong dependence on the extraction time. After the first 5 min of MW extraction time, the yield was 0.53%, and the maximum yield (0.75%) was achieved at 30 min, after which no more essential oil was hydrodistillated, although the extraction time was prolonged for 60 min.