Characterization of drying kinetics and moisture diffusivity in finger millet using fluidized bed drying

Finger millet, a staple cereal, undergoes various processing methods such as germination and fermentation to enhance bioactive compounds for health-promoting food applications. Drying is a crucial step in this process, affecting shelf life and quality. This study investigates the drying characteristics of two types of finger millet: wet millet (Sample A) and germinated millet (Sample B) in a fluidized bed dryer at temperatures of 40 °C, 50 °C, and 60 °C, with two different fluidizing velocities. The drying kinetics followed a curvilinear falling rate pattern, suggesting a diffusion-controlled drying mechanism. Notably, Sample B exhibited higher effective moisture diffusivity than Sample A. The drying kinetics were accurately modelled using the Page model, with a strong correlation between experimental and predicted values. These findings have significant implications for optimizing drying conditions in industrial food processing, potentially improving energy efficiency and product quality.