Drying kinetics and effective moisture diffusivity of bamboo shoot slices undergoing microwave drying

摘要

Effect of microwave power on moisture content, moisture ratio, drying rate, drying time and effective moisture diffusivity (D_(eff)) of bamboo shoot was investigated using microwave drying. To study the effect of microwave power on drying, bamboo shoot samples (250 g) were dried at different power levels ranging from 140 to 350 W. To determine the kinetic parameters, drying data were fitted to various models based on the ratios of differences between initial and final moisture contents and equilibrium moisture content. Among the models proposed, Wang and Singh model gave a better fit for all drying conditions used. By increasing microwave output power, the D_(eff) values increased from 4.153 × 10~(-10) to 22.835 × 10~(-10) m~2 s~(-1). A third-order polynomial relationship was found to correlate the D_(eff) with moisture content. Further scope of this research work would include the effect of certain factors (shrinkage, case hardening, distortion of product and shape of bamboo shoot samples as an infinite slab) of practical significance to improve the model.