Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Dairy Science

First Advisor

Padmanaban G. Krishnan


High protein and high fiber residues from ethanol processing streams may be utilized in food applications. Heat-processed wet cake from the ethanol plant was identified as a starting material for further optimization. Food Grade Distillers Grain (FDDG) was produced exclusively for this study employing successive washing schemes, freeze drying and particle size reduction. FDDG was further fractionated into Fine FDDG and Coarse FDDG using a 0.2mm and 0.5mm screen, respectively, in conjunction with an ultracentrifugal mill. The nutritional compositional and functional traits of FDDG were determined. Wheat flour was fortified using FDDG substitutions at the 0, 5, 10, and 20% levels using fine FDDG and coarse FDDG. The particle size distribution of the various flours were determined. The effects of both particle size and fortification at 5 to 20% levels were compared against Control samples (0% fortified Bread flour). Significant increases in protein content and TDF content were achieved in fortified blends at each level of fortification. Differences in effects of particle size (0.2mm or 0.5mm) were less discernible. Bread produced using the flour blends were evaluated for loaf weight, loaf volume crumb structure and bread Texture Profile Analysis (TPA). The TPA yielded data on bread hardness, cohesiveness, resilience, springiness and chewiness. The wheat flour used in the study had a significant proportion (77.7%) that ranged from 75 to 150 microns in particle size. A large proportion of the Fine FDDG (88.72%) and Coarse FDDG ranged in particle size from 150 to 400 microns. FDDG ranged in protein content from 36.01% (Fine FDDG) to 37.59 % (Coarse FDDG). Fine-grinding appeared to result in a slight but statistically significant higher protein content. Fine and coarse FDDG showed no differences in dietary fiber content (TDF). Dietary fiber was the predominant constituent in FDDG at 51.3%TDF in Fine FDDG and 49.5% TDF in Coarse FDDG. Bread wheat flour that had 2.67% TDF, was significantly improved in fiber content with the addition of up to 20% DDGS. TDF content in the blends went up to 13.74% with the inclusion of 20% Coarse FDDG. Enrichment of wheat flour at 5, 10 and 20% levels of substitution brought about a steady and significant increase in fiber content. This was observed with both the fine FDDG and the coarse FDDG.

Library of Congress Subject Headings

Bread -- Composition.
Distilling industries -- By-products.
Food -- Fiber content.
Food -- Protein content.
Enriched foods.
Distillers feeds.



Number of Pages



South Dakota State University


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