2008 Annual Report
Multi-instrument SKCS comparisons and calibrations with researchers in Kansas, Nebraska, and Texas will be completed. The effect of environment on protein content and composition of isolated hard and soft endosperm fractions will be determined. Wet milling, dry milling, extrusion and fermentation quality of selected sorghum lines will be conducted. Color compounds, phenolics, and other small molecules in sorghum from weathered and sound grain; evaluate grains for markers of insect and fungal damage and infestation will be characterized and cataloged.
Exotic germplasm will be evaluated for desirable processing traits (e.g. ethanol yield). GxE stability of processing quality in sorghum lines showing desirable processing traits will be evaluated. Impact of compounds found in sorghum grains as a result of weathering, mold, insects, or fungal invasion on food and processing quality will be determined. Processing methods to reduce or eliminate impact of environmental damage will be investigated.
Improved techniques for extracting and analyzing sorghum proteins will be developed. Methods for extracting and purifying sorghum proteins for industrial and food applications will be determined. Formulations for the production of wheat free sorghum foods from batter type systems will be optimized.
Optimization of batter type product formulations for production of wheat free sorghum based foods will be continued. Visco-elastic dough formation in artificial sorghum protein-starch dough systems will be investigated and changes to sorghum proteins during mixing will be elucidated and compared to wheat proteins during mixing. Methods for disruption of sorghum protein bodies in sorghum flour to free proteins for interaction during mixing will be developed. Starch and protein content and composition from diverse sorghum lines will be determined and related to ethanol and lactic acid yields. The extent of protein-protein interaction and protein-starch interaction in artificial sorghum dough systems will be determined. Methods for the use of reduction-oxidation systems to form a visco-elastic dough directly from sorghum flour will be developed. Sorghum proteins and starch will be modified to improve functionality in food. Pre-treatment methods for altering protein and starch composition in sorghum for improved ethanol and lactic acid yields will be developed.
Fermentation quality of sorghum: The effect of mashing on sorghum protein cross-linking and its relationship to fermentation quality of sorghum was conducted. Lines that showed more cross-linking tended to have lower fermentation efficiencies (i.e. took longer to reach maximum ethanol yields). Based on this research, a fraction of polymeric proteins were identified as markers that could be used to predict ethanol fermentation efficiency in sorghum. This research supports ARS Strategic Plan Goal # 2 “Enhance the competitiveness and sustainability of rural and farm economies” via the actionable strategy “Improve understanding of relationships between raw material/feedstock composition, component molecular structure/physical structure, and end-use quality, function and end-user acceptance.”
Sorghum is a drought resistant cereal crop grown in the central U.S. The majority of the U.S. sorghum crop is currently used for animal feed. However, increasing amounts are being used for fuel ethanol production. For ethanol plants located in the sorghum growing region of the U.S., sorghum is the major feedstock. During ethanol production, the starch in cereal grains is converted to glucose and then fermented to ethanol. This process involves heating the material (mashing), during which sorghum proteins form cross-links. These cross-links form web-like structures that trapped starch and reduced fermentation efficiency. Identifying sorghum lines that do not develop strong protein cross-links may lead to the development of improved sorghum hybrids for the ethanol industry. This research supports ARS Strategic Plan Goal #2 "Enhance the competitiveness and sustainability of rural and farm economies" via the actionable strategy "Improved understanding of relationships between raw material/feedstock composition, component molecular structure/physical structure, and end-use quality, function and end-user acceptance" and NP306 "Quality and Utilization of Agricultural Products" Component 1. Quality characterization, preservation, and enhancement, problems a-c.
5.Significant Activities that Support Special Target Populations
Schober, T.J., Bean, S., Boyle, D.L. 2007. Gluten-free sorghum bread improved by sourdough fermentation: Biochemical, rheological and microstructural background. Journal of Agricultural and Food Chemistry. 55:5137-5146.
Ciacci, C., Maiuri, L., Caporaso, N., Bucci, C., Del Giudice, L., Massardo, D., Pontieri, P., Fonzo, N., Bean, S., Ioerger, B.P., Londei, M. 2007. Celiac disease: In vitro and in vivo safety and tolerability of wheat-free sorghum food products. Clinical Nutrition. 26:799-805.
Ioerger, B.P., Bean, S., Tuinstra, M.R., Pedersen, J.F., Erpelding, J.E., Lee, K.M., Herrman, T.J. 2007. Characterization of polymeric proteins from vitreous and floury sorghum endosperm. Journal of Agricultural and Food Chemistry. 55:10232-10239.
Taylor, J., Bean, S., Ioerger, B.P., Taylor, J. 2007. Preferential binding of sorghum tannins with gamma-kafirin and the influence of tannin binding on kafirin digestibility and biodegradation. Journal of Cereal Science. 46:22-31.
Wang, D., Bean, S., Mcclaren, J., Seib, P., Madl, R., Tuinstra, M., Shi, Y., Lenz, M., Wu, X., Zhao, R. 2008. Grain Sorghum is a Viable Feedstock for Ethanol Production. Journal of Industrial Microbiology and Biotechnology. 35:313-320.
Wu, X., Zhao, R., Bean, S., Seib, P.A., Mclaren, J.S., Madl, R.L., Tuinstra, M., Lenz, M., Wang, D. 2007. Factors impacting ethanol production from grain sorghum in the dry-grind process. Cereal Chemistry. 84(2):130-136.
Zhao, R., Bean, S., Ioerger, B.P., Wang, D., Boyle, D.L. 2008. Impact of Mashing on Sorghum Proteins and Its Relationship to Ethanol Fermentation. Journal of Agricultural and Food Chemistry. 56:946:953.