BIO-INDUSTRIAL USES OF SORGHUM PROTEINS
Grain Quality and Structure Research Unit
2010 Annual Report
1a.Objectives (from AD-416)
1) Determine the adhesive properties of sorghum proteins isolated from DDDGS, bran and flour,.
2)Determine the chemical properties of sorghum proteins related to adhesive and bio-plastic quality, and.
3)Improve the quality of sorghum protein based adhesives and bio-plastics.
1b.Approach (from AD-416)
Optimize the isolation of sorghum proteins from DDGS, bran, and/or sorghum flour and characterize the chemical properties of the isolated proteins and their functional properties in adhesives and bio-plastic production. Isolate proteins from sorghum grains with known attributes (e.g. hardness) to determine the factors that influence the quality of sorghum based adhesives and bio-plastics.
Sorghum kafirin proteins were extracted from sorghum DDGS and sorghum flour using acetic acids, HCl-ethanol and NaOH-ethanol methods, respectively. Protein composition and chemical properties such as protein structure and molecular weight were analyzed using AOC standard method, FT-IR, lab-on-a-chip electrophoresis, size-exclusion chromatography (SEC), and reversed phase high-performance liquid chromatography. Thermal properties of extracted protein were analyzed using thermal gravimetric analysis (DSC) and differential scanning calorimetry.
Extraction conditions (methods) and particle size of DDGS had a significant effect on protein yield, purity, and thermal properties. Extraction yield increased as particle size decreased. Seventy percent extraction rate was obtained with DDGS particle size less than 0.25mm. Acetic acid and NaOH-ethanol produce protein with higher purity than protein extracted with HCl-ethanol protocol. Highest purity produced was 98.9% which was from the acetic acid extraction protocol.
ADODR monitoring is conducted via e-mail, phone calls, and on-site visits/meetings.