ARS | Publication request: Alkaline extraction of phenolic compounds from intact sorghum kernels

Submitted to: International Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 2, 2012
Publication Date: August 14, 2012
Repository URL: http://doi:10.1111/j.1365-2621.2012.03138.x
Citation: Blackwell, D.L., Herald, T.J., Bean, S., Gadgil, P. 2012. Alkaline extraction of phenolic compounds from intact sorghum kernels. International Journal of Food Science and Technology. Blackwell, D. L., Herald, T. J., Bean, S. R. and Gadgil, P. (2012), Alkaline extraction of phenolic compounds from intact sorghum kernels. International Journal of Food Science & Technology. doi: 10.1111/j.1365-2621.2012.03138.x p. 1-5.

Interpretive Summary: Decortication is an abrasive method of bran removal and is not as effective for grains with softer pericarp such as sorghum. Thus, health promoting compounds that are found within the bran may be lost due to processing. Direct extraction of the health promoting compounds found in sorghum using an alkaline solvent was achieved without the need to decorticate or grind the grain. Furthermore, natural colorants within the bran may be isolated as a by-product of the waste stream to add further value. Alkaline extraction may hold advantages over the traditional decortications method with grains of soft endosperms. Direct isolation of the health promoting compounds using an alkaline extraction method eliminates the need to process sorghum into flour or meal.

Technical Abstract: An aqueous sodium hydroxide solution was employed to extract phenolic compounds from whole grain sorghum without decortication or grinding as determined by Oxygen Radical Absorbance Capacity (ORAC). The alkaline extract ORAC values were more stable over 32 days compared to neutralized and freeze dried treatments.