Properties of solvent extracted low-oil corn distillers dried grains with solubles

Abstract

Corn-based ethanol is exponentially growing in the US, as is the need for valuable uses for coproducts of the production process, such as distillers dried grains with solubles (DDGS). Currently, DDGS is used as livestock feed, thereby replacing some 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.