Characterisation of wheat flour and gluten proteins using buffers containing sodium dodecyl sulphate

Abstract

Abstract The application of buffers containing the anionic detergent sodium dodecyl sulphate (SDS) to the study of wheat flour proteins is described. SDS‐containing buffers are more effective than alternative solvents, including those which contain a cationic detergent, e.g. cetyltrimethylammonium bromide, in terms both of their ability to solubilise wheat proteins and of their suitability as buffers for column chromatography. Thus, a solvent containing 0.069m (2%) SDS solubilises a high proportion (95%) of flour protein, and gel filtration chromatography on columns of Sepharose CL‐4B in the presence of 3.47 × 10 −3 M (0.1%) SDS, particularly when used in conjunction with polyacrylamide gel electrophoresis, is a powerful tool for the detailed analysis of flour proteins. This technique enables flour proteins to be resolved into three major groups which have been identified as glutenins, gliadins and albumins plus globulins. It can be used to monitor increases in the molecular size of the glutenin fraction during the preparation of gluten from flour, and preliminary data suggests that there may be a correlation between the molecular size of this protein fraction and the breadmaking quality of the flour.