ISOLATION TREATMENTS AND EFFECTS OF GLIADIN AND GLUTENIN FRACTIONS ONDOUGH MIXING PROPERTIES

The effects of a range of solvents and buffers commonly used in the is olation of gliadin and glutenin polypeptides were evaluated on the fun ctionality of gliadins and glutenins in a small-scale dough mixer. Fra ctions from two wheat cultivars that differed in mixing behavior and h igh molecular weight glutenin subunit composition were studied. Dialys is or addition of dilute acetic acid rather than water before drying w as critical for mixing behavior to remain unaltered. The mixing behavi or of gliadin and glutenin fractions treated with a range of buffers a nd solutions, including sodium dodecyl sulfate, urea, aqueous alcohols and acetonitrile, and low pH buffers was unaltered after dialysis aga inst acetic acid. In contrast, exposure of both gliadins and glutenins to reducing. agents altered the mixing behavior of these fractions. T he results will guide research on the isolation of single polypeptides for functionality studies and development of a simple dough for struc ture and function studies.