EFFECT OF SEQUENTIAL ABRASION ON STARCH COMPOSITION OF 5 CEREALS FOR ETHANOL FERMENTATION

Five cereals were abraded successively on a Satake abrasive test mill to enhance the starch contents of the pearled grains to improve fermen tation efficiency of fuel ethanol plants. Tempering the cereals to 12. 5% and 15.0% moisture had no consistent effects on rates of grain mass removal by abrasion but final starch losses to the abraded fines coul d be minimized by optimizing grain moisture content. Increasing abrasi on time from 10 to 55 s increased the average grain mass removal from 3.5 to 19.5% in four hulless cereals but 70 s of abrasion was needed t o remove 32.6% of two-row barley to obtain a comparable starch content in the pearled grain. On a dry basis, the pearled grain starch levels were: Canadian Prairie Spring (CPS) red wheat (73.4%); CPS white whea t (72.2%); two-row barley (71.0%); fall rye (70.4%); and triticale (69 .1%), which represented, on average, a 12% increase in starch content over those of the original grains. Ethanol yields per tonne of ferment ation feedstock were increased by 6.5-22.5% as a result of abrasion, w hich would substantially increase ethanol plant throughput and grain f ermentability. (C) 1998 Canadian Institute of Food Science and Technol ogy. Published by Elsevier Science Ltd. All rights reserved.