Effect of high-temperature short-time treatment of wheat flour on gluten vitality and structure

The effect of high-temperature short-time (HTST) applications on gluten in its natural flour environment was investigated. Changes occurring in HTST-treated samples during storage and in samples subjected to severe thermal denaturation were studied. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) profiles of the gluten polypeptides, and the intrinsic fluorescence, were modified only in the heat-denatured preparation. On the other hand, after HTST treatment changes in the extrinsic fluorescence (8-aniline-1-naphthalene sulfonate [ANS] binding) revealed enhanced surface hydrophobicity, which however, regressed on storage. Consistent with these observations was the amount of the associated water. It appears that it is the gluten surface that is mainly affected by HTST treatment, and this could represent a very early stage of heat damage of gluten.