Title: GLUCOSE OXIDASE EFFECTS ON WHEAT FLOUR ALBUMINS AND GLIADINS. Author
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 22, 2005
Publication Date: September 11, 2005
Citation: Tilley, M. 2005. Glucose oxidase effects on wheat flour albumins and gliadins. Abstract No. 238 in: 2005 AACC International Annual Meeting Program Book. p.144. Meeting Abstract. Technical Abstract: Chemical oxidants are routinely added to flour to modify rheological properties (shorten mixing time, improve gas retention, lower energy requirement for dough mixing) and enhance breadmaking performance (increase loaf volume and improve crumb structure). The elimination of potassium bromate, and possibly other chemical oxidant additives, presents a challenge to the baking industry. Alternative oxidation methods need to be found since industrial baking has been standardized with bromate. Substitution of chemical oxidants with enzymes is a desirable approach because enzymatic reactions are very specific, with little or no reactivity outside of the substrate. Oxidoreducing enzymes such as glucose oxidase (GOX) have been proposed as improvers for the baking industry. The mechanism of improvements caused by GOX is not well understood. Following dough-mixing wheat flour with and without the addition of GOX, the different protein classes were extracted and analyzed by electrophoresis and size-exclusion HPLC. The most significant effects were observed to occur in the albumin (water-soluble) and gliadin (alcohol-soluble) protein groups. A significant increase in protein concentration and molecular weight distribution was shown in the albumin fraction by SE-HPLC. Further analysis revealed that this is due to changes in gliadin solubility. Gliadins are generally not soluble in water. However, the inclusion of GOX in flour-water dough renders the gliadins more water-soluble. The biochemical interactions are responsible for this behavior, indicating the possible effects on end-use properties.