Abstract:

The thin layer drying characteristics of carrot slices were investigated and moisture content (relative to dry matter)
was modeled as a function of drying time under different conditions of temperature, air flow rate and sample thickness.
Meanwhile, based on Fick’s diffusion law, the effective diffusion coefficients of water (Deff) in carrots were calculated and
modeled as well. Results showed that the thin layer drying kinetics of carrots could be described by the Page equation, the
coefficients of equation were obtained through regression analysis, and the equations of Deff vs. air temperature, air flow rate
and sample thickness were obtained by multiple linear regression. The experimentally observed Deff values increased from
0.84 × 10-9 to 6.69 × 10-9 m2/s with increasing drying temperature, air flow rate and sample thickness.

Key words: carrot, drying, dynamic modeling, moisture diffusion coefficient