Compositional Analysis of Defatted Syrup from a Corn Ethanol Dry-Grind Process as a Feedstock for Biobased Products

A characterization study was conducted on defatted corn syrup (DCS) from an ethanol dry-grind process and its potential as feedstock for biobased products and biofuel is evaluated. Analyses included total solids, ash content, total protein, amino acids, inorganic elements, starch, total carbohydrates, lignin, organic acids, glycerol, and presence of functional groups. Total solids content was 37.4% (±0.4%) by weight, and the mass balance closure was 101 (±0.5%). Total carbohydrates [27% (±5%) wt of dry solids] were composed of starch (6.3%), soluble monomer carbohydrates (12%), and nonstarch carbohydrates (9.3%). Hemicellulose components (structural and nonstructural) were xylan (6%), xylose (1%), mannan (1%), mannose (0.4%), arabinan (1%), arabinose (0.4%), galatactan (3%), and galactose (0.4%). On the basis of measured physical and chemical components, a biochemical conversion route and subsequent fermentation to value-added products is a good possibility. Though less promising as a feedstock for liquid transportation fuels, DCS has the potential to meet current United States demand (20–30 million kg per year) for succinic acid. Finally, even without any form of hydrolysis, DCS could also potentially meet global demand for histidine (360,000 kg per year).