(626w) High Protein Content Distillers Dried Grains with Solubles

Distillers dried grains with solubles (DDGS) with 30% protein content and 40% neutral detergent fiber content (1), is a coproduct of conventional dry grind ethanol plant.  Due to its high fiber content, DDGS is used primarily as ingredient in ruminant animal diets.  Reducing fiber and increasing protein content will allow DDGS use as an ingredient in poultry and swine diets.  Increase in protein and decrease in fiber content of DDGS can be achieved by modified dry grind corn process (E-Mill process) that fractionates corn kernel (to recover germ and fiber as coproducts) prior to fermentation (2).  Further increase in protein content and decrease in fiber content can be achieved by extraction of oligosaccharides and other soluble carbohydrates or by acid precipitation of the protein from E-Mill DDGS. 

Two corn hybrids were fractionated and dry grind processed to produce E-Mill DDGS.  E-Mill DDGS was further processed to produce protein isolate and concentrate products.  The yield of isolate product was too low (<2%) to be feasible economically.  However, concentrate yield was about 43 to 52%.  Protein content of concentrate product for one of the hybrids was 60%.  

1. Liu, K.  2011.  Chemical composition of distillers grains, a review.  Agric. Food Chem. 59: 1508-1526.
2. Singh, V., Johnston, D. B., Naidu, K., Rausch, K. D., Belyea, R. L., and Tumbleson, M. E.  2005.  Comparison of modified dry-grind corn processes for fermentation characteristics and DDGS composition.  Cereal Chem. 82:187-19.