Effect of heat treatments on starch pasting, particle size, and color of whole-grain barley

Heat processing treatments are beneficial to reducing microbial contaminants in whole grains prior to human consumption. However, the effects of these heat treatments on properties of barley that may impact its milling and food processing quality are not well understood. The aim of this study was to examine the effects of three different heat treatments (micronization, roasting, and conditioning) on whole-grain barley physical and functional properties including color, flour particle size after milling and flour pasting viscosity. These effects were examined using three diverse barley cultivars (CDC Rattan, CDC McGwire, and CDC Fibar) to determine if varieties respond differently to heat processing. All three heat treatments increased flour slurry viscosity (a measure of flour processing quality), but this effect was observed in only two out of the three barley cultivars. Roasting and conditioning resulted in reduced flour particle size upon milling, which could influence further end product processing and nutritional properties. Heat treatments also altered kernel color. Overall, this research shows that heat treatments can change properties of barley that may affect its function in food applications.