Drying kinetics of barley grains and effects on the germination index

Abstract

This study aimed to assess the drying kinetics of barley grains and, using mathematical modeling, to evaluate the diffusivity during drying and after drying to evaluate the effect of high drying temperatures on the seed germination index for malt production. Three drying temperatures 40, 60 and 80°C were used. The last two, 60 and 80°C, reached moisture close to ideal for storage with 6 and 4 hours respectively; at 40°C, drying process took 12 hours and would still take additional hours to reach 13% moisture on a dry basis. Drying temperature influenced the germination power. The protein content was reduced according to increased drying time. The diffusivity coefficient was higher in conventional than in intermittent drying, probably due to heat loss in the intermittent process. It was observed that higher the temperature higher is the diffusivity. Ks values of the Omoto model ranged from 1.07 to 2.05E-4.