Start Date: Nov 03, 2009
End Date: Mar 31, 2011
The aim of the first portion of the project is to identify and quantify the primary factors and interactions that affect flowability, handling, and storage behavior of ethanol coproducts (including distillers dried grains with solubles (DDGS) and distillers wet grains (DWG)), especially those that result in poor coproduct flowability. Independent variables that will be controlled include composition (including moisture content, lipid content, residual starch content, etc. – by varying the ratio of CDS/DWG in the DDGS), and storage and handling conditions (including storage time, consolidation pressure, temperature, and humidity). Dependent variables include material handling characteristics and flowability behavior, as quantified by physical properties and Jenike and Carr Indices. Practical industrial practices and/or remediation strategies (i.e., altering coproduct processing conditions, modifying storage conditions, using flow agents, or other measures) will be identified, investigated, and developed for use at commercial operations. The aim of the second portion of the research is to develop pelleted distillers grains-based feed products that can be used for traditional livestock (i.e., beef, dairy, swine, poultry), or new target species (such as fish). Pelleted products will be developed (in close collaboration with SDSU animal nutritionists) via pellet mill processing and extrusion processing using DDGS as a protein source. Advantages to pelleting of feed can include nutrient-densification, better palatability, improved nutrient availability as a result of cooking that occurs during processing, and improved storability and flowability behavior. Thus these pelleted feed products will have intrinsic values higher than currently-available distillers grains, which are stored, shipped, and fed as-is in loose, granular bulk form. The aim of the third portion of the research is to develop food products from distillers grains for human consumption. High-fiber, high-protein, low-starch DDGS-based flour will be developed by fractionating distillers grains in order to concentrate various nutrient streams; specific fractions will then be selected for further processing (which may include milling, bleaching, deodorizing, sterilizing, etc.), after which they will be incorporated into various ingredient matrices for baking and subsequent product testing. Ingredient functionality and nutritional assessment will be conducted to determine if these materials are viable for use in human foods, and if, by increasing the protein and fiber contents, either improved food products or new foods can be developed based on DDGS. These novel products will provide new utilization avenues for ethanol coproducts.