title: Effect of soy skim from soybean aqueous processing on the performance of corn ethanol fermentation.
abstract: The feasibility of using soy skim, a co-product of the aqueous processing of soybeans, in ethanol production from corn was evaluated. Specific growth rates were compared when Saccharomyces cerevisiae was grown in soy skim and peptone-yeast extract media supplemented with glucose. Such soy skim was proved to be a good nitrogen source for yeast growth. Next, fermentation of dry-ground corn to ethanol using soy skim as the media was simulated on 1.5-L scale. Replacing water with soy skim increased the initial ethanol production rates by 4-32% while final ethanol yield was about 39 g/100 g dry corn, similar to the result when water was used. Solid and protein contents in the finished beer increased with the addition of soy skim. Thus, replacing water in corn-ethanol fermentation with soy skim is feasible, and may improve the economics of both aqueous soybean processing and corn ethanol fermentation.
authors.affiliation: Department of Food Science and Human Nutrition, Center for Crops Utilization Research, 2312 Food Science Building, Iowa State University, Ames, IA 50011, USA.
authors.forename: Linxing
authors.initials: L
authors.lastname: Yao
authors.forename: Tong
authors.initials: T
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
mesh_terms: D000704:Analysis of Variance; D056804:Biofuels; D002851:Chromatography, High Pressure Liquid; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000187:drug effects*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development*; D041942:Soy Milk / Q000737:chemistry / Q000494:pharmacology*; D013025:Glycine max / Q000737:chemistry*; D003313:Zea mays / Q000378:metabolism*
chemical_list: D056804:Biofuels; D000431:Ethanol