Mathematical modeling and thin-layer drying kinetics bamboo slices on convective tray drying at varying temperature

Abstract

This study investigated the thin-layer drying characteristics of bamboo slices in a convective tray dryer with three different temperatures viz., 55, 65 and 75C and fit the experimental data to four drying models to identify the best fit model and drying temperature. The drying rate curves of slices typically demonstrate a smooth diffusion controlled drying behavior. The drying rate at the beginning of the process was generally lower at 55C, with a marked difference between it and the other temperatures. The difference between MRs increased gradually at the commencement of drying and the time required for reaching equilibrium moisture content decreases with increasing temperature. The average value of coefficient of determination (r2) and RMSE revealed values varied between 0.94–0.99 and 0.014–0.073, respectively. Page and logarithmic models obtained the highest r2 and least RMSE at all temperatures and better reflected the drying mechanism of bamboo slices than exponential model. Rehydration ratio elevated when salt solution used for rehydration and the weight gain was more irrespective of temperature. Superior rehydration was noticed when the slices were dried at 65C, and it was relatively poor at 75C and 55C. Products dried at 65C recorded highest scores for visual appearance and colour at the end of drying.