The role of arabinoxylan in determining the non-linear and linear rheology of bread doughs made from blends of wheat (Triticum aestivum L.) and rye (Secale cereale L.) flour

Abstract

Part of the role which arabinoxylan (AX) plays in bread making relates to its impact on the bulk rheology of dough. However, the actual mechanisms by which it influences dough rheology are still not well understood. An evident research approach is to use endo-β-1,4-xylanases (XYLs) to hydrolyze AX and hence increase their solubility. Here, the AX population in (i) wheat dough and (ii) mixed cereal doughs made from blends of wheat flour (WF) and rye flour (RF) was subjected to hydrolysis by XYL from Aspergillus aculeatus (XAA) or Bacillus subtilis (XBS). Non-linear and linear dough rheology was studied by uniaxial extensional and small-amplitude oscillatory shear measurements, respectively. Low dosages of XBS or XAA in wheat or mixed cereal doughs changed neither their non-linear nor their linear extensional rheological responses, presumably because limited AX hydrolysis did not result in high losses of water binding and/or because dough constituents bound the liberated water. A high dosage of XBS or XAA led to extensive hydrolysis of AX and considerably decreased the linear extensional viscosity. This decrease resulted from an altered dough water distribution.