Degree Type

Dissertation

Date of Award

1986

Degree Name

Doctor of Philosophy

Department

Agricultural and Biosystems Engineering

Abstract

Breakage susceptibility has become an important quality characteristic of corn traded in the international market. Centrifugal impacters like the Wisconsin Breakage Tester may be used for rapid determination of breakage characteristics of different corn lots. However, the high dependence of breakage on moisture content necessitates testing at or correcting to a common moisture level;The objective of this study was to quantify the effects of grain moisture, drying methods, and variety on breakage susceptibility values of shelled corn and also to derive a generalized moisture correction equation to allow use of testers like the Wisconsin Breakage Tester in grain market channels;Breakage susceptibility of 576 samples was measured by a Wisconsin Breakage Tester. Breakage susceptibility increased by 40% (compounded) per percentage point decrease in grain moisture content. Heated air drying at 93.3(DEGREES)C increased breakage susceptibility of corn by 2 to 3 times. Breakage susceptibility of heated air dried corn increased by 0.35 percentage point per percent increase in harvest moisture within the range of 23% to 32%. Harvest moisture did not affect samples slow-dried by room temperature air;Breakage susceptibility of corn dried by heated air was also found to increase by 0.74 percentage point for every percent point decrease in the dry down moisture level from 18% to 12%;If dried by heated air, Pioneer 3780 was the least susceptible to breakage, while Pioneer 3720 was most susceptible to breakage. Varietal difference in breakage susceptibility was not observed if the corn was slow-dried by room air;A generalized moisture adjustment equation was derived for compensating the variation in breakage values resulting from changes in grain moisture;Breakage susceptibility values were not correlated with sample test weight or particle size of ground corn.

DOI

https://doi.org/10.31274/rtd-180813-6883

Publisher

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

Copyright Owner

Pradip Kumar Dutta

Language

en

Proquest ID

AAI8703701

File Format

application/pdf

File Size

221 pages

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