378 Effect of adding lactic acid during steeping corn with different initial moisture content on steepwater profiles and wet milling results.

P. YANG and S. R. Eckhoff. Graduate Research Assistant and Professor, respectively, Department of Agricultural Engineering, University of Illinois, Urbana, IL 61801.

Reducing steep time by adding lactic acid instead of in situ fermentation was studied by steeping corn at two different initial moisture levels in 2,000 or 3,000 ppm SO(2) with three levels of lactic acid (0, 0.28 or 0.55%) for 18 hr. Three levels of lactic acid, were added to fresh steepwater. Starch yield from those steep conditions was comparable to that from 24 hr batch steeping. Adding lactic acid decreased steepwater pH, accelerated SO(2) absorption and increased the amount of solids released from corn. Adding lactic acid did not increase starch yield for the hybrid used, but did allow for good separation at 18 hr. Germ skimming was easier and protein content in starch was lower when lactic acid was added. Pasting properties of starch were not affected by adding lactic acid.