Title: Investigation of Conditions for Rapid Cereal Starch Isolation Using Sonication Authors
Submitted to: Meeting Abstract
Publication Type: Other
Publication Acceptance Date: April 22, 2005
Publication Date: May 22, 2005
Citation: Park, S., Bean, S., Wilson, J.D. 2005. Investigation of conditions for rapid cereal starch isolation using sonication. Program Book of the 3rd International Wheat Quality Conference. 2005. Abstract. p.397 Technical Abstract: Cereal starches have been isolated by hand-washing, wet-milling, or enzymatic methods (EM). However, these procedures are often tedious and time-consuming. Therefore, the objectives of this study were to develop new, rapid and reproducible starch isolation methods using sonication. Decorticated sorghum flour was sonicated in a pH 10.0 buffer with 2% SDS and 2% reducing agent at a solvent to sample ratio of 20:1, followed by water-washing. Sonication times (2, 4, 6, 8, and 10 min) and different reducing agents ('-ME, DTT, and sodium meta-bisulfite) were tested. Protein content of starch was only 0.35-0.45% (db) after a 2-min sonication (using any reducing agent) and was reduced further to 0.15-0.30% (db) using longer times. The sonicated starch was comparable to starch obtained by the EM which takes several hours to complete. Starch yield (db) and protein content (db) were 74 and 0.83% for the EM starch, and 74 and 0.42% for the sonicated starch. The color of starch obtained by sonication showed a similar L (brightness) value, (93.9 vs. 93.8) and lower b (yellow) value (2.99 vs. 3.80) than the EM starch. Physicochemical properties of starches from different types of sorghum (hard vs. soft, normal vs. waxy) and the purification of starch from other cereals will be presented. Wheat, corn, rice, and barley starches were also rapidly isolated using this procedure.