Influence of Moisture Content and Temperature on Thermal Conductivity and Thermal Diffusivity of Rice Flours

Abstract

The thermal conductivity and thermal diffusivity for four types of rice flours and one type of rice protein were determined at temperatures ranging from 4.8 to 36.8 °C, bulk densities 535 to 875.8 kg m−3, and moisture contents 2.6 to 16.7% (w.b.), using a KD2 Thermal Properties Analyzer. The thermal conductivity of rice flours and rice protein increased with the increase in temperature, moisture content as well as with increase in bulk density. Thermal diffusivity decreased with increase in moisture content, increase in temperature and bulk density. The thermal conductivities values obtained were within the range of 0.045 to 0.124 W m−1 K−1 whereas the thermal diffusivity values were in the range of 0.094 to 0.138 mm2 s−1.