Breakage Susceptibility Reduction by Short-Term Tempering of Corn

ABSTRACT THE effects of short-term (0-60 min) tempering of corn before cooling on the breakage susceptibility and moisture removal during cooling was studied using both thin-layer and deep bed drying processes. Thin-layer tests at three temperatures and four final moisture contents showed breakage susceptibility was dramatically increased for drying below 19% but can be reduced by tempering with most of the reduction occurring in the first thirty minutes. Moisture content removal by cooling was increased by increasing tempering time and drying air temperature. Study of crossflow, crossflow with turning and rack-type dryer configurations confirmed the effects of tempering on breakage susceptibility and moisture removal during cooling found by the thin layer tests. Moisture removal was also affected by the dryer configuration, with the largest removal for the crossflow configuration. Heat energy input per mass of water removed was significantly reduced by including cooling in the drying process, with larger reductions at 17% than at 15% moisture content.