Mathematical Modelling of Thin-layer Drying Process of Bamboo (Bambusa bambos) Shoots at Varying Temperature

Abstract

Abstract
The present study was carried out for understanding the drying mechanism in bamboo shoots and thereby helpful for selection and designing of appropriate drying system. Thin-layer drying characteristics of bamboo shoot slices were determined experimentally as a function of temperature using a laboratory tray dryer. Six mathematical models (Henderson and Pabis, Logarithms, Newton, Page, Two term, Wang and Sing) for describing the thin-layer drying behaviour of bamboo shoot slices were investigated. The tests were conducted using three air temperatures (75, 80 and 85°C). Out of the six models considered, Page model best reflected the drying mechanism of bamboo shoot slices. The performance of these models was investigated by comparing the coefficient of determination (R2), reduced chi-square (χ2) and root mean square error (RMSE) between the observed and predicted moisture ratios. The drying air temperature had the significant effect on the drying kinetics of bamboo shoot slices. Effective moisture diffusivity varied from 4.22×10-12 to 5.56×10-12 m2/s over the temperature range studied, with an activation energy of 28.60 kJ/mol. The temperature dependence of the diffusivity coefficients was described satisfactorily by a simple Arrhenius-type relationship.

Keywords: Bamboo shoot slices; Activation energy; Drying kinetics; Effective moisture diffusivity; Moisture ratio; Thin-layer drying