Drying Characteristics of Cereal Powder

Abstract

Drying characteristics of cereal powder were measured and analyzed by using TGA (Thermo Gravimetric Analyzer). The results revealed that
(1) The cereal powder with initial moisture contents above about 20%d.b. dryed in the first falling rate period, followed by the second falling rate period. In the 2nd falling rate period the diffusion coefficients were not constant, and the diffusion equations became non-linear.
(2) The drying constants in the first and second falling rate period were measured. It could be confirmed that the both drying constant had Arrhenius type temperature dependency.
(3) The drying rates in the second falling rate period were estimated from the numerical solutions of the introduced non-linear diffusion equation by CRANK-NICOLSON method, and the results agreed well with the measured results.