Location: Grain Quality and Structure Research
Project Number: 3020-43440-002-007-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2019
End Date: Jul 31, 2023
Objective:
The objective of this project is to investigate the relationship between soil sulfur levels and sorghum protein composition and nutritional quality. Soil sulfur levels are known to impact synthesis of cysteine residues in cereal proteins and impact disulfide cross-linking. Disulfide cross-links negatively impact sorghum protein nutritional quality, thus soil sulfur levels may be an important agronomic factor that impacts sorghum grain quality.
Approach:
Sorghum hybrids will be planted at multiple locations in Oklahoma with known sulfur levels, providing a "sulfur gradient" across the growing locations. If necessary, sulfur fertilizer will be added to increase the levels of sulfur plants are exposed to. Grain will be harvested and analyzed for physical grain traits (kernel hardness, diameter and weight), and protein content. Protein composition will be determined both for kafirin composition and disulfide bound polymeric protein complexes. Finally, in-vitro pepsin digestibility will be measured for both raw and cooked sorghum flour to relate sulfur levels to protein composition to nutritional quality of sorghum.
