Investigation on thin-layer drying kinetics of sprouted wheat in a tray dryer

Abstract

The thin-layer drying behavior of sprouted wheat (cv. PBW 550) was experimented at different drying periods, such as 24 h, 36 h and 48 h. The samples were dried in a tray dryer at 50–80οC at an interval of 10°C. The moisture ratio was fitted to the six thin-layer drying models, and the performance of the models was assessed by statistical parameters. The Wang and Singh model has accurately predicted the drying behavior of sprouted wheat for all sprouting periods and drying temperatures. In addition, the effective moisture diffusivity of grain sprouts at three drying periods (24 h, 36 h and 48 h) of sprouted wheat was increased from 1.79 × 10-9 to 2.58 × 10-9 m2 s-1, 1.921 × 10-9 to 2.781 × 10-9 m2 s-1 and 1.858 × 10-9 to 2.561 × 10-9 m2 s-1 with increase in drying temperature from 50oC to 80oC. Moreover, at the above-stated drying periods, the activation energy for sprouted wheat was 11.357 kJ mol-1, 11.428 kJ mol-1 and 9.427 kJ mol-1, respectively. Therefore, thin-layer drying of sprouted wheat was successfully simulated between 50°C and 80°C for various drying periods. This study provided imperative information to understand the drying behavior and relationship between various drying parameters of sprouted grains that could produce nutritive functional flour.