Mathematical modeling of swirling flow fluidized bed infrared green tea drying process

In this study, the drying behavior of green tea in the stationary bed and swirling flow-fluidized bed-infrared driers were experimentally investigated and mathematical modeling was performed. Drying experiments were done for 100 W, 250 W, 500 W, 750 W and 1000 W infrared powers, mass losses were measured depending on drying time. Dimensionless mass ratio, moisture content, mass shrinkage rate, drying rate were calculated depending on mass loss and time. Mathematical modeling was performed by using 22 model equations to estimate the thin layer drying behavior of green tea in the stationary bed and swirling flow-fluidized bed-infrared driers. To compare the drying models 14 evaluation criteria were used and the best model was determined. In addition, water extract, total ash, total polyphenols, caffeine, raw cellulose and moisture were determined for dried green tea samples. As a result, it was determined that the best suitable powers were 750 W and 500 W and the best drying models were Midilli-Kucuk and Aghbashlo et al. for stationary bed and swirling flow-fluidized bed, respectively. The highest value of water extract included quality parameters was obtained 36.06% at 750 W in stationary bed and 44.04% at 500 W swirling flow-fluidized bed.