Hydrocyclone procedure for starch-protein separation in laboratory wet milling.

A hydrocyclone system for starch-protein separation was developed for use with 1-kg samples in laboratory corn wet milling. A Doxie 5 hydrocyclone with all but one cyclone plugged and a five-pass starch washing system was compared to a traditional starch tabling procedure using both regular dent and waxy corn hybrids. The tabling procedure gave 3-4% higher starch yields in dent corn and 2-3% higher starch yields in waxy corn. Tabled starch had less protein (0.33 and 0.45% for dent and waxy, respectively) than the Doxie 5 hydrocyclone-separated starch (0.64 and 0.65% for dent and waxy, respectively). Using a Doxie Type A single hydrocyclone instead of the Doxie 5 increased the starch yield; however, protein in starch increased to 1.29 and 0.97% for dent and waxy, respectively. Design and operational differences may account for the different results. The hydrocyclone procedure reduced the time required for starch-protein separation by 75%. It also eliminated the requirement of a large floor area for starch tables, reduced the potential for operator error, and more closely simulated the starch-protein separation process used in industrial operations. The reduced testing time and ease of use will make the hydrocyclone procedure useful for comparing milling procedures or different corn hybrids.