Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/10/2007
Publication Date: 1/2/2008
Citation: Srinivasan, R., Yadav, M.P., Belyea, R.L., Rausch, K.D., Pruiett, L.E., Johnston, D., Tumbleson, M.E., Singh, V. 2008. Fiber separation from distillers dried grains with solubles using a larger elutriation apparatus and use of fiber as a feedstock for corn fiber gum production. Biological Engineering 1(1):p.39-49. Interpretive Summary: In dry grind corn processing, ethanol is produced from the starch portion of the kernel and the remaining material is dried to produce distillers dried grains with solubles (DDGS). This relatively low value material is the only coproduct (other than carbon dioxide) and has a limited number of uses. In order to generate new value added coproducts and improve the economics of ethanol production, a simple method was developed to separate the light fiber fraction of the DDGS away from the non-fiber material using air fractionation. The fiber fraction of this separation was tested successfully to see that it could be used to prepare a valuable product called corn fiber gum (CFG). This food grade gum is a complex carbohydrate that can be used to stabilize natural flavors in soft drinks or as an emulsifier in other food or industrial products. This finding will be useful to commercial manufacturers who are trying to develop a new commercial product based upon corn fiber gum. If successful, it will lead to new markets for DDGS, which will benefit U.S. corn processors and corn growers.
Technical Abstract: In an earlier study, the combination of sieving and elutriation (air flow) was found to be effective in separating fiber from distillers dried grains with solubles (DDGS); the elutriation column diameter used was 63 mm. Larger quantities of fractions were needed for carrying out studies on production of valuable products from the fractions. In this study, an elutriation apparatus with a larger elutriation column (155 mm ID) was developed to process DDGS at higher rates. Fiber separation from DDGS using the larger scale (155 mm) elutriation apparatus was evaluated and compared with results from the 63 mm column. Fiber was evaluated for corn fiber gum (CFG) production, which has uses as an emulsifier and thickener in foods. Processing of commercial DDGS material using the larger scale apparatus with higher operating input rate gave results similar to that obtained using smaller scale apparatus. Protein and fat contents were higher in the heavier fractions (material that settled in the bottom of the elutriation column); fiber content (neutral detergent fiber) in the lighter fractions (material carried to the top of the elutriation column) was higher than the initial material. The large elutriation apparatus did not change fiber separation characteristics. Total CFG yields from fiber varied from 35.8 to 44.2%. CFG yields were comparable to CFG yields from corn wet milling fiber. Fiber separated from DDGS has potential use as feedstock for CFG production.