Influence of Moisture Content and Bulk Density on Thermal Diffusivity of Green Teas

The thermal diffusivity of green teas has been used as engineering parameter in the design of processes and machines for drying, storing and aeration. The thermal diffusivity of green teas was determined and its changes with moisture content, bulk density investigated. The thermal diffusivity values of green teas decreased from 8.126×10^-8 at 250 kgm^-3 to 5.037×10^-8 m²s^–1 at 550 kgm^-3. The change of the thermal diffusivity of green teas at different moisture content shows that it increased from 8.281×10^-8 at 5.3% db to 12.617×10^-8 m²s^–1 at 70.0% db and from 7.497×10^-8 at 5.3% db to 12.464×10^-8 m²s^–1 at 70.0% db, respectively, as bulk density increased.