Abstract

Microwave drying characteristics of safou pulp (Dacryodesedulis) were evaluated in a laboratory scale microwave dryer. The drying experiments were carried out at 0.42, 0.56 and 0.70 kW. Three commonly used mathematical models were evaluated with the experimental data. The results indicated that the Page model was most adequate in predicting moisture transfer for safou pulp, just a falling rate period was observed in the microwave drying processes; the values of effective diffusivity were increased with the increment of the experimental power levels. The regression equations of drying rate against drying duration or moisture were found to describe very well the drying characteristics for safou pulp; it took nearly 70% of total drying time to remove the latter half of moisture in the microwave drying safou pulp. The above findings can facilitate the design and operation of microwave drying of safou pulp.

Key words: Dacryodesedulis, microwave drying characteristics, modelling, diffusivity, drying rate.