Impact of low-temperature storage on quality of high-moisture corn grain

Wang, Ning

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https://hdl.handle.net/2142/88058 Copy

Description

Title

Impact of low-temperature storage on quality of high-moisture corn grain

Author(s)

Wang, Ning

Issue Date

2015-07-20

Director of Research (if dissertation) or Advisor (if thesis)

Rodriguez, Luis F.

Department of Study

Engineering Administration

Discipline

Agricultural & Biological Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Corn
• Mold
• High moisture

Abstract

Alternative energies such as bioethanol have been developed to reduce the dependence on non-renewable fossil fuels, which are also responsible for national security issues and increases in greenhouse gases. Bioethanol has gained attention because it can be blended with gasoline at different levels, and it is thus compatible with current motor engines. Bioethanol also helps to prevent air pollution and early ignition. Traditional or first-generation bioethanol is produced from food crops, predominantly corn in the U.S., whereas advanced or second-generation bioethanol is generated from cellulosic materials such as corn stover. Early harvesting of corn can increase the yields of grain and stover and reduce the lignin content of the stover and as a result, can reduce the major costs of feedstock and stover pretreatment in traditional and advanced bioethanol production. Motivated by these advantages, frozen storage is an innovative way of storing the problematic high-moisture corn grain left from an early harvest. However, the efficiency and reliability of this approach are challenges because of yield fluctuations due to agronomic factors and undesirable weather during the harvesting season. As an alternative, low-temperature short-term storage (LSS) is a promising way to relieve the pressure to freeze the corn grain prior to the onset of inclement weather and to reduce energy waste of freezer when bad weather does occur. This study focuses on the appropriate storage duration of high-moisture corn grain at low temperatures. By completing two objectives, this study provides suggestions on storage duration for high-moisture corn grain in low-temperature short-term storage (LSS) according to a significant decrease in quality. The first objective is the determination of the point at which the quality of stored grain is significantly changed. The second objective involves suggestions based on those findings. Grain harvested at 35% moisture content was stored at 20°C, 8°C and 4°C for up to 40 days and at -20°C for 6 month. After storage, the grain was tested by 100-g wet milling and whole-kernel plating to measure quality. For each quality parameter, suggestions proposed based on the significant changes with storage duration, as determined by Duncan’s multiple range test (MRT). Conclusive suggestions on the storage duration for high-moisture grain at 8°C and 4°C are offered by compiling suggestions according to all quality parameters. Most of the quality parameters assessed in this study showed significant changes indicating a quality decrease, which I defined as an undesirable decrease in a valuable component or an increase in mold infection during storage. For certain quality parameters, the quality decrease is much larger at 20°C than at 4°C and 8°C. For all quality parameters, the suggested durations for 4°C are shorter or equal to that for 8°C. Overall, the suggested duration for storing grain with a 35% moisture content is 8 days at 8°C and 12 days at 4°C. The selection of temperature should consider both the expected storage duration and also the processing capacity. Please be advised that the suggested duration may vary if other specific aspects of grain quality are considered.

Graduation Semester

2015-8

Type of Resource

text

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http://hdl.handle.net/2142/88058

Copyright and License Information

Copyright 2015 Ning Wang

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