DETERMINATION OF NEUTRAL SUGARS IN CORN DISTILLERS DRIED GRAINS, CORN DISTILLERS DRIED SOLUBLES, AND CORN DISTILLERS DRIED GRAINS WITH SOLUBLES

Corn distillers' dried grains (DDG), corn distillers' dried solubles (DDS), and corn distillers' dried grains with solubles (DDGS) are coproducts from ethanol production. Knowledge of the carbohydrate composition of these coproducts will increase their potential for further processing. Materials were first hydrolyzed by trifluoroacetic acid, and the resulting neutral sugars were analyzed by high-performance liquid chromatography. Glycerol (3.5-10.2%), arabinose (2.8-10.0%), xylose (3.2-14.1%), mannose (0-2.6%), glucose (5.6-18.8%), and galactose (1.1-2.6%) were found in these ethanol coproducts. Corn DDS had the highest content of neutral sugars (39%), of which glucose accounted for about half of this total. Neutral carbohydrates from the hydrolysis of the 80% methanol soluble fraction (monosaccharide and low molecular weight oligosaccharides) from these corn distillers' products were mostly glycerol and glucose.