Thin layer drying behaviour of fermented cocoa (Theobroma cacao L.) beans

To assess the impact of a rest interval and bean turning on the thin-layer drying behavior of fermented cocoa beans, beans of mixed Trinitario varieties were dried in a cabinet oven at three temperatures (40, 50, 60°C) using three drying regimes, namely; continuous drying, intermittent drying (drying for 8h with a rest period of 16h), and intermittent drying with turning of beans.  Moisture content, water activity, pH and colour attributes were measured and sensory evaluation of the cocoa liquor carried out on selected samples.  Drying curves were constructed and drying rate constants (k) and effective diffusivity (Deff) values determined. Keywords: Oven-drying; Fick’s Law; Rate constant; Diffusion coefficient