Title: Properties of Low-oil Corn Distillers Dried Grains with Solubles (DDGS) Authors
|Saunders, Jessica - SOUTH DAKOTA STATE UNIV|
Submitted to: Biomass and Bioenergy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 9, 2009
Publication Date: September 5, 2009
Citation: Saunders, J.A., Rosentrater, K.A. 2009. Properties of low-oil corn distillers dried grains with solubles (DDGS). Biomass and Bioenergy. 33:1486-1490. Interpretive Summary: The U.S. corn ethanol industry is rapidly growing. Additionally, the quantity of coproducts resulting from ethanol manufacture, such as distillers dried grains with solubles (DDGS), is also increasing. Currently, DDGS is primarily used as livestock feed. But, as the industry continues to grow, there is a push to develop value-added uses for DDGS. Many plants are interested in extracting corn oil from the DDGS to produce biodiesel. If oil is extracted from DDGS, however, the resulting chemical and physical properties of the resulting feed products may be substantially altered. The goal of this study was to determine various physical and chemical properties for DDGS that was commercially solvent extracted. The resulting low-oil DDGS exhibited water activity, thermal properties, bulk density, and angle of repose values similar to unmodified DDGS. Color values were substantially lighter, however. Compositionally, fat levels were much lower, while protein and fiber were higher than traditional DDGS. This information will be valuable to ethanol manufacturers and livestock producers alike, as more uses for ethanol coproducts are implemented.
Technical Abstract: Corn-based ethanol production is exponentially growing in the U.S. As the use of ethanol as a fuel source increases, so does the need to find valuable uses for coproducts of the production process, such as distillers dried grains with solubles (DDGS). DDGS is a good source of fiber and protein. Currently, DDGS is sold by ethanol processors and used as livestock feed, thereby increasing profit for the production plants, and replacing corn components in animal diets. As the industry continues to grow, there will be an increased need to find additional uses for DDGS. Physical and chemical properties of coproduct streams are becoming increasingly investigated, as these characteristics affect many aspects of utilization, such as target species, optimal dietary substitution rates, transportation, flowability, and behavior during storage. Potential avenues for future use of DDGS may include value-added feed, food, and industrial products. Additionally, much interest lies in extracting oil from DDGS to produce bio diesel and other products. If oil is extracted from DDGS, the resulting chemical and physical properties of the remaining constituents may be substantially altered. The objective of this study was to quantify, using standard laboratory methods, physical and chemical property values for low-oil DDGS. The extracted DDGS exhibited water activity, thermal properties, bulk density, and angle of repose values similar to unmodified DDGS. Color values were substantially lighter, however. Additionally, fat levels (2.7% db) were much lower, while protein (34.0% db) and fiber (8.4% db) were higher than traditional DDGS. Results from this study will be valuable to ethanol manufacturers and livestock producers alike, as more uses for ethanol coproducts are implemented. Thus more value can be extracted from the humble kernel of corn.