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item Johnston, David

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2004
Publication Date: 4/1/2004
Citation: Singh, V., Johnston, D., Rausch, K.D. Enzymatic maize milling process for dry grind ethanol. Meeting Abstract. 55th Annual Starch Conference, Detmold Germany, April 20-24, 2004. Paper #3.6.

Interpretive Summary:

Technical Abstract: Conventional dry grind maize processing is very efficient in producing ethanol but does not produce high valued coproducts. In a conventional dry grind ethanol plant only one coproduct, dried distillers grains with solubles (DDGS) is produced. DDGS is sold as an animal food product, mainly for ruminant animal diets, due to its high fiber content, and is low in value. The U.S. ethanol production capacity is projected to nearly double by the end of year 2006. Most of this increase in ethanol capacity, will come from new dry grind maize facilities. Using the conventional process, increases in dry grind ethanol production means that the supply of distiller's dried grains with solubles (DDGS) will increase proportionately. Use of DDGS as feedstock to non-ruminant animal diets will help in maintaining the demand-supply balance. However, the fiber content in DDGS needs to be reduced, before DDGS can be widely used as non-ruminant animal foodstuff. New process modifications have been developed for the conventional dry grind maize process such as quick germ (QG) and quick germ quick fiber processes (QGQF). These process modifications allow cost effective removal of coproducts such as germ and pericarp fiber at the beginning of the dry grind maize process, prior to fermentation. A new process modification called enzymatic milling (E-Mill) for dry grind has been developed which is an improvement over the QG and QGQF processes and also allows recovery of endosperm fiber as a valuable coproduct. In this study, the effects of three different modified dry grind maize processes, quick germ (QF), quick germ and quick Fiber (QGQF) and enzymatic milling (E-Mill) were observed. Fermentation characteristics and DDGS composition were determined and compared to the conventional dry grind maize process. Significant effects were observed on fermentation characteristics and DDGS composition with these modified dry grind processes. The E-Mill processes increased fermentation capacity by 27%, reduced the fiber content of DDGS by 81% and increased the protein content of DDGS by 105%, relative to the conventional dry grind process. The QF and the QGQF processes also improved the fermentation and DDGS characteristics but not as significantly as the E-Mill process.