Capillary Electrophoresis of Wheat Gliadin: Initial Studies and Application to Varietal Identification

WheaT gllllen proTeins have importanr functional properties. and are reliable indicators of genOType. They are also very heterogeneous. demanding use ofpoweJ:ful analytical techniques. Gel electrophoresis methods are lvidely used for gluten analysis, blll they are labor-inrensive. and their daTa are not easily quant((ied. A1ethods of capillmy electrophoresis (CE) are now available that promise to overcome these disadvantages. We here report successful application and optimization of two CE procedures for gliadin analysis. The first procedure used 0.06 mollL sodium borate buffer. pH 9.0. containing 200 mLiL acetonitrile + 10 giL sodium dodecyl sulfate; separations were excellent. but reproducibility was difficult to maintain. The second buffel; 0.1 mol/L phosphate. pH 2.5. containing a linear hydrophilic polymel; overcame this problem, providing separations of gliadins that are rapid. high-resolution, automatic. and easily quant~(ied. CE analyses ofgliadin also reliably differenriate varieties ofall us. wheat classes. CE is thus a valuable technique for gliadin analysis. complementary to other methods of electrophoresis and chromatography. CE has much potential to become a routine tool for wheat varietal ident~(ication and class((ication. and for prediction of quality.