Thermal conductivity of granular rice starches

Thermal conductivities of four types of granular rice starches, regular, lo w protein, waxy and low protein waxy, were measured at bulk densities of 60 0 and 800 kg/m(3), temperatures of 20, 50 and 80 degrees C, and moisture co ntents of 4, 20 and 40% (wet basis), using a line-source thermal probe syst em equipped with a computerized data acquisition system. A completely rando mized experimental design with factorial treatment structure resulted in a total of 72 treatments, each with 3 replications. The thermal conductivity was significantly different among various rice starches. Low protein and wa xy rice starches had higher thermal conductivities than regular and low pro tein waxy rice starches. Thermal conductivity increased significantly with increases in bulk density, temperature and moisture content. Prediction mod els were developed to calculate thermal conductivity values for practical a pplications.