Wheat flour proteins: The selectivity of solvents and the stability of gliadin and glutenin fractions of stored flours

A gel‐filtration study of extraction of wheat proteins by eight separate solvent systems is presented and the nature of the protein classes extracted by each solvent has been quantified. As judged by carboxymethylcellulose ion‐exchange chromatography, gel‐filtration and starch‐gel electrophoresis, no storage changes have occurred in wheat flour gliadin and glutenin proteins extracted from flours kept at 25, 12 and ‐20 °C for 18 months. SDS‐polyacrylamide‐gel electrophoresis shows minimal change in the gluten molecular weight distribution on storage. Six and twenty‐year‐old flours were also tested.