Investigation of the Role of Arabinoxylan on Dough Mixing Properties in Native and Model Wheat Dough Systems

Abstract

The aim of this work was to investigate and compare the effect of arabinoxylan (AX) addition and incorporation on the mixing properties of native and model doughs of different wheat types, to get more insight into the role of AXs in dough formation. In the experiments, flour samples of a wheat variety (normal starch type) and two wheat lines (waxy and high amylose) were used. Model doughs were composed by fractionating flours into starch and gluten followed by subsequent reconstitution according to their original gluten to starch ratio. AX isolate was dosed in 1% and 3% to the native and model doughs. Incorporation of AX was performed by reduction and re-oxidation of wheat dough with dithiothreitol (DTT) and KIO₃, respectively.
Model doughs behaved similarly to native doughs thus were found appropriate for the model experiments. In general, higher AX level resulted higher dough consistency in every dough system compared to the corresponding base dough, however, the extent of the growth was different. In case of assumed AX incorporation only small differences were found in the mixing properties compared to AX addition. Based on sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) analysis, some minor but clear changes were observed in the protein subunit profile of AX containing doughs compared to base doughs, but no difference was identified between doughs made by AX addition and AX incorporation. However, the characterization of the gluten-AX interactions requires more detailed investigation, in which a pure gluten-starch-AX model system can offer a valuable, well-defined matrix.