Skip to main content
ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #250390
Title: Chemical and physical properties of fuel ethanol coproducts relevant to value-added uses

Author
item BHADRA, RUMELA - South Dakota State University
item MUTHUKUMARAPPAN, K - South Dakota State University
item Rosentrater, Kurt

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2010
Publication Date: 9/1/2010
Citation: Bhadra, R., Muthukumarappan, K., Rosentrater, K.A. 2010. Chemical and physical properties of fuel ethanol coproducts relevant to value-added uses. Cereal Chemistry. 87(5):439-447.

Interpretive Summary: During the last several years, the corn-based fuel ethanol industry has been one of the fastest growing industrial sectors in the U.S. Coproducts from ethanol include distillers dried grains with solubles (commonly known as DDGS), distillers dried grain (DDG), distillers wet grains (DWG), and carbon dioxide. Distillers grains contain high proportions of protein, fiber, energy, and other nutrients, and are primarily used as livestock feed ingredients. The objective of this study was to examine various chemical and physical properties of DDGS, DDG, and DWG from several commercial plants. These properties included crude protein, crude fat, crude fiber, neutral detergent fiber, acid detergent fiber, crude ash, residual starch, glucose, carbon partitioning, moisture content, water activity, bulk density, thermal properties, color (Hunter L*, a*, b*), angle of repose, particle size distribution, and particle shape. Overall, it appears that several possibilities for adding value to ethanol coproducts exist, including producing additional ethanol, extracting value-added compounds, using as human food ingredients, or using as fillers for biocomposites.

Technical Abstract: One of the fastest growing industries in the United States is the fuel ethanol industry. Since 2000 there has been an increase of more than 600%, in this industry. The major coproducts from corn-based ethanol include distillers dried grains with solubles (DDGS) and carbon dioxide. DDGS is used as a livestock feed since it contains high quantities of protein, fiber, amino acids, and other nutrients. The goal of this study was to quantify various chemical and physical properties of DDGS, distillers wet grains (DWG), and distillers dried grain (DDG) from several plants in South Dakota. Chemical properties included crude ash, Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), crude fiber (CF), crude protein, crude fat, and total starch content in each of the samples. Physical properties included moisture content, water activity, bulk density, thermal properties, color (L*, a*, b*), and angle of repose. We also conducted image analysis and size determination of the DDGS particles. Carbon group characterization in the DDGS and DDG samples were determined using NMR spectroscopy. Results from this study showed several possibilities for using DDGS in application other than animal feed. Possibilities include harvesting residual sugars, producing additional ethanol, producing value-added compounds, using as human food additives, or even using as inert fillers for biocomposites.