Degree Type

Dissertation

Date of Award

2001

Degree Name

Doctor of Philosophy

Department

Agricultural and Biosystems Engineering

First Advisor

Thomas L. Richard

Second Advisor

Carl J. Bern

Abstract

The objective of this project was to develop value-added disposal/reuse alternatives for corn masa processing residues (i.e., waste, or byproduct, slurries). To accomplish this, the project was divided into four distinct phases. The first phase entailed identification and quantification of relevant physical and nutritional properties of typical corn masa processing residues. As a result, these byproducts appear suitable for use as livestock feed additives, or components thereof. These byproducts are very high in moisture content, but dried, they are high in fiber, and would probably be best suited for ruminant diets. Additionally, when dried, these products have a substantial calcium content, so there may exist potential for use as a calcium source for livestock rations. The second phase encompassed blending and extruding corn masa processing byproducts with soybean meal on a laboratory-scale, and investigating the effects of blend ratio, extrusion temperature, and extruder screw speed on extrusion processing variables and final extrudate product physical and nutritional characteristics. The third phase entailed blending and extruding corn masa processing byproducts with soybean meal on a pilot-scale, and investigating the effects of blend ratio, extrusion temperature, and extruder screw speed on extrusion processing variables and final extrudate product physical and nutritional characteristics. Extrusion processing during these stages produced extrudates with nutritional properties similar to the raw ingredient blends, excellent durability, and little product expansion. The final phase of the project encompassed development of a computer model to assess the economics of various disposal and recycling alternatives for corn masa processing byproducts. It was determined that, under the current economic climate, direct shipping of the raw byproduct slurry is the most economical disposal option for masa processing residues.

DOI

https://doi.org/10.31274/rtd-180813-15342

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu

Copyright Owner

Kurt August Rosentrater

Language

en

Proquest ID

AAI3003267

File Format

application/pdf

File Size

566 pages

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