Modeling of thin-layer solar drying kinetics of cassava noodles (tapioca)

Abstract

This work aimed at modeling thin-layer solar drying of cassava noodles (tapioca). The selection of good drying models for dryers helps to improve their efficiency. Drying data of tapioca was obtained using a forced convection solar dryer. The treatment combinations of the experiment comprise of air flow velocities (V) of 1.5, 2.5, and 3.5 m/s; drying layer thicknesses (B) of 0.48 and 0.72 cm; and initial moisture contents (M_i) of 297, 186, and 122% (dry basis). Eleven thin-layer drying models from literature, in addition to a new model developed in this work were all fitted to the solar drying data of tapioca. Least square regression analysis was carried out and comparison between drying models was made using goodness of fit statistical parameters. Drying kinetics of the tapioca was determined. Effective moisture diffusivity and activation energy of the tapioca were also determined. The results obtained from the analysis show that the new model (Modified Aghbashlo model) was best fitted to the drying data of tapioca. The determined effective moisture diffusivity of the tapioca samples varied from 4.93 x10^-11 to 8.82 x 10^-11 m²/s. Also the activation energy of the tapioca samples was determined as 28 kJ/mol.

Keywords: Cassava noodles, drying models, statistical parameters, effective moisture diffusivity, activation energy, Nigeria