Journal of Advances in Food Science & Technology

This study investigated the drying kinetics of thin-layer banana slices (Musa spp.) using a domestic microwave oven across five controlled power levels. Fresh banana slices, prepared to a uniform thickness of 0.25 cm and initial moisture content of approximately 80% (wet basis), were dehydrated to a final moisture content ranging between 17% and 18% (wet basis). Drying time demonstrated a dramatic inverse relationship with microwave power, decreasing from 30 minutes at 180 W to just 11 minutes at 900 W.

Analysis of the drying rate curve revealed that higher power levels (600 W and 900 W) induced a shorter constant rate and lengthier falling rate period, indicating effective volumetric heating, whereas lower power levels (180 W to 450 W) were predominantly controlled by the internal diffusion mechanism associated with significant constant rate period and smaller falling rate period. Four common thin-layer drying models (Newton, Page, Modified Page, and Henderson and Pabis) were fitted to the experimental moisture ratio data. The Modified Page model provided the superior statistical fit across all tested power conditions, achieving the highest average coefficient of determination (R² average of 0.9769) and robustly describing the non-linear drying kinetics. The findings confirm that microwave power is the primary control parameter, and careful study is essential to capitalize on kinetic efficiency for high-power density heating.