Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation


Agriculture, Food and Environment


Biosystems and Agricultural Engineering

First Advisor

Dr. Michael D. Montross

Second Advisor

Dr. Samuel G. McNeill


Wheat is one of the most widely consumed staple foods in the world, supplying both nutritional and caloric requirements for billions of people. The rising global population and increased food demand behooves all stakeholders across the wheat supply chain to significantly increase their output and efficiency. Beyond the target for increased farm yields, dietary, nutritional, and health requirements along with their continuous supply must be satisfied with improved storage and processing schemes. Post-harvest changes in wheat can result in a significant reduction in its quality. Such losses could be qualitative and/or quantitative, impacting its physical, physiological, organoleptic, and nutritional attributes. However, a significant portion of these changes are also associated with ubiquitous biological activities of wheat-borne insects and microorganisms. A lab scale study of soft red winter wheat stored in hermetic bags and conventional, aerated conditions with 5 varieties, 3 storage temperatures and up to 6 months storage duration were examined for changes in specific microbial profiles and composition of α-amylase, ß-glucan, total protein content, and long chain fatty acids along with their germination potential. Samples of Agrimax 438, Pembroke 2021 (from Lexington, Kentucky), another Pembroke (from Princeton, Kentucky) Pioneer 26R10 and Truman were used. Each hermitic bag contained 60 g of whole wheat kernels, and were heat sealed. The conventionally stored samples consisted of 60 g of wheat in 1-quart (0.946 L) steel cans covered with lids that were fitted with a nylon filter membrane (0.45µm) to allow gaseous exchange but minimal microbial contamination. The cans and hermetically sealed bags were stored in the same temperature-controlled chambers at 2, 10 and 27°C. All samples were conditioned to the same moisture content range of 12.8-13.4% and as-received samples were taken at the point the bags and cans were prepared. Samples were taken every 2 months for 6 months to evaluate quality changes with a destructive sampling procedure. Parameters of storage time and temperature were found to be significant for all studied variables with an inverse relationship in most cases. The nutritional profile was improved after the sprouting process with the employment of stresses of salt, pH (acid), and temperature. Whole wheat kernels were screened for foreign materials and broken seeds, were soaked in distilled water for 24 h and placed on white paper towels in white plastic bowls (46 g in each bowl) to sprout in the dark for a period of 3 days at a temperature of 20°C and a relative humidity of 94%. Samples were withdrawn every 24 h and their α-amylase, total protein, long-chained fatty acids, and antidiabetic potentials were examined. Sprouting was observed to initiate a significant breakdown in macromolecules with the stresses causing different alterations in the studied characteristics. The viability of wheat kernels was monitored using a custom-built imaging system with enhanced focus and compensation for light and color bias in the images. Individual seeds had their weight and images captured before and during a 4-day sprouting process to monitor changes in their size, shape, color, and weight. Parameters such as major and minor axis lengths, eccentricity, and mean red, blue, and green pixels were examined over time. Results indicated that kernel weight, size and color are suitable indicators for detecting viability during germination.

Digital Object Identifier (DOI)

Funding Information

This research was supported in part by the United States Department of Agriculture National Institute of Food and Agriculture (USDA NIFA) Multistate Project NC213 under accession number 1018137.