The effect of mixing on glutenin particle properties: aggregation factors that affect gluten function in dough

Previously we reported that the SDS insoluble gel-layer: the Glutenin Macro Polymer (GMP) can be considered as a gel consisting of protein particles. These glutenin particles have a size of about 10-(1)-10(2) mum and consist of HMW-GS and LMW-GS only. In GMP isolates from flour, the particles are spherical. In isolates from dough, glutenin particles have lost this shape. This seems relevant, since mixing disrupts the particles and the mixing energy required for dough development correlated with the glutenin particle size in flour. The question studied in this paper is how changes at a glutenin particle level affected the subsequent process of gluten network formation during dough rest and if this could be used to explain resulting dough rheological properties. To this end, we studied how various mixing regimes affected the dough properties during and after resting (elasticity). We cannot fully explain the differences in the final dough properties observed using parameters such as the quantity of GMP in flour, the quantity of re-assembled GMP in dough and the size of re-assembled glutenin particles. However, other parameters were found to be important: (1) the Huggins constant K' reflecting the tendency of glutenin particles to interact at level II of the Hyperaggregation model; (2) the composition of glutenin particles affecting the potential to form smaller or larger particles and (3) for over-mixed dough, covalent re-polymerisation at the so-called level I of hyperaggregation. Using these parameters we can better explain dough viscoelasticity after resting. (C) 2004 Elsevier Ltd. All rights reserved.