Hot air drying of cooked and uncooked tarhana dough, a wheat flour-yoghurt mixture

摘要

Drying behaviour of cooked (CTD) and uncooked tarhana dough (UTD) slabs (1, 3 and 6 mm) were determined at constant air temperature (80 degreesC) and velocity (1.86 m/s). Both samples dried in the falling rate period. An analysis of variance (ANOVA) revealed that slab thickness and cooking process significantly affected the drying rate. The effective moisture diffusivity values of CTD and UTD samples were determined from drying experiments using Fick's diffusion model. Effective diffusivity was higher in cooked sample than in uncooked one (1.3-23.5x10(-10) and 0.99-10.OX10(-10) m(2)/S, respectively). This was attributed to the development of channels and pore structure during starch gelatinisation in the cooked sample.