Evaluation of the Drying Kinetics of Swirling Fluidized Bed Drying and Performance Assessment on the Nutritional Properties of Bentong Ginger

Abstract Bentong ginger (BG), grown in a high-altitude area of Bentong, Malaysia, has a similar scientific name to the common ginger species and has been patented by the Malaysian government. BG is known for its larger size and pungent taste and is nutritionally rich in antioxidants such as gingerols, which are responsible for a wide range of pharmacological and physiological effects in human health. This study presents the effect of swirling fluidized bed drying (SFBD) compared with oven drying (OD) and freeze-drying techniques (FD) on the drying kinetics, antioxidant potential, and 6-gingerol concentration of BG. The Midilli-Kucuk model showed the best fit at explaining the thin layer drying behavior of the BG for OD and SFBD, whereas the Page model showed the best fit for FD. The experimental results showed that SFBD reduces the total drying time (250 min) and energy consumption (160.4976 kWh/kg) with higher drying rate (0.1813 g/min) and moisture diffusivity (2.4317 × 10-10 m2/s). In addition, the dried BG sample from the SFBD exhibited a slightly higher DPPH inhibition (89.2%) and the best option to preserve the 6-gingerol compound (2.626 mg/mL) in the Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry (LC-QTOF/MS) analysis. Thus, the SFBD approach proved to be a feasible method for drying ginger.