ARS | Publication request: Changes in Physical Properties during Dry Grind Processing of Corn

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 19, 2010
Publication Date: May 16, 2010
Citation: Rosentrater, K.A., Liu, K. 2010. Changes in Physical Properties during Dry Grind Processing of Corn. AOCS Annual Meeting and Expo, Phoenix AZ, May 16-19, 2010.

Technical Abstract: Corn-based ethanol has dramatically increased in the U.S. in recent years. So too has the quantity of coproducts. These are composed of nonfermentable components (i.e., protein, lipid, fiber, and ash) from the corn kernel. These materials are separated from the ethanol and then subjected to various separations and drying processes. The most common coproduct is distillers dried grains with solubles (DDGS). DDGS has become widely used as a livestock feed ingredient. One of the key issues associated with DDGS is poor flowability. The objective of this study was to identify where in the manufacturing process “stickiness” is imparted to the coproduct material. Eight samples were collected from two corn-based fuel ethanol plants, and included raw corn, cooked slurry, liquefied mash, whole stillage, thin stillage, wet cake, distillers dried grains (i.e., no added solubles), and DDGS. Each of these samples was dried at 50º for 24 h, then milled to 0.5 mm. Properties tested included Carr Testing (angle of repose, aerated bulk density, packed bulk density, compressibility, angle of spatula, total flowability index, angle of fall, angle of difference, dispersibility, floodability index), thermal conductivity, thermal diffusivity, and color (Hunter L, a, b). Results of these tests will be presented and compared, and implications for the industry will be discussed.