ARS | Publication request: USE OF ULTRASOUND AND EXTRUSION PROCESSING TO IMPROVE THE NUTRITIONAL AND FUNCTIONAL QUALITY OF SORGHUM FLOUR

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2005
Publication Date: July 16, 2005
Citation: Singh, H., Bean, S., Alavi, S. 2005. Use of ultrasound and extrusion processing to improve the nutritional and functional quality of sorghum flour [abstract]. 2005 IFT Meeting, New Orleans, July 16-20, 2005. p. 99B-23.

Technical Abstract: Sorghum is a drought resistant cereal grain grown mainly in the southern great plains of the U.S. Interest in using sorghum in human food products has recently been increasing. This is due in part to the development and promotion of white food grade sorghums; those with a white grain produced on a tan plant. Flour from such sorghums is white in color and has a bland, neutral flavor. Sorghum is a safe food for persons with celiac disease, now estimated at 3 million in the U. S. The proteins in sorghum do not have the same functionality as those in wheat. One reason for this is the encapsulation of the proteins in protein bodies. Sorghum proteins are held in spherical bodies and have been recognized as major cause low digestibility and poor functionality. To disrupt these protein bodies and free the proteins for interaction, both extrusion and ultrasound were used to process sorghum flour. Sonication resulted in a significant increase in the solubility of polymeric proteins, suggesting that disruption of protein bodies did occur. Likewise, extrusion processing significantly altered the polymeric protein profile when sorghum proteins were analyzed by size-exclusion chromatography. Analysis of extruded flours using a farinograph showed significant changes in mixing behavior and water absorption. Extruded flours were also used to produce bread and pasta, both products where proteins play important functional roles. Pasta made from extruded sorghum flour had less die swell and cooking loss than the control flours. These studies show that the functionality of sorghum flour can be increased and that disruption of the protein bodies may play a role in this.