MATHEMATICAL MODELING AND THIN-LAYER DRYING KINETICS OF 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. PRACTICAL APPLICATIONS Consumers are inclining towards taking health-promoting products from nontraditional sources. Bamboo shoots are now an important food crop in the international food market. Bamboo shoot being low in fat, high in dietary fiber and rich in mineral content, like an ideal vegetable, has been used traditionally the world over. The market for bamboo shoots is growing steadily, and more and more people are developing a taste for them. Processing while keeping nutrients intact and enhancement of shelf life of the value-added products assume great significance for business potential due to seasonal availability of bamboo shoots. It would demand process standardization for small-scale processing units. Therefore, the use of hot air in controlled cabinet drying through convective air is far more rapid and provides uniformity and hygiene for industrial food drying processes. Therefore, this study deals in detail about dynamics of thin-layer drying kinetics of bamboo slices and its quality evaluation by rehydration and sensory process.