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Differing Effects of Mechanical Dough Development and Sheeting Development Methods on Aggregated Glutenin Proteins

¹New Zealand Institute for Crop & Food Research Limited, Private Bag 4704, Christchurch 8001, New Zealand. ²Corresponding author. E-mail: suttonk@crop.cri.nz.

Dough development using sheeting and mechanical dough development (MDD) were compared with respect to the effect the mixing method had on the molecular size distribution and degree of protein thiol exposure of the aggregated glutenin proteins. Although sheeting imparts a lower rate of work input on doughs than does MDD mixing, changes in protein aggregation patterns during mixing were similar for both methods of dough development, indicating that protein disaggregation was important in the process of dough development. In both systems, a reduced rate of change in the protein aggregation patterns was associated with optimum dough development. The MDD mixing was characterized by increasing exposure of the thiol groups on the SDS-insoluble glutenin during mixing while the sheeting process resulted in fewer exposed thiol groups on both SDS-soluble and SDS-insoluble glutenin proteins. This suggested that disulfide bond rupture may not be a required process in dough development and that high effective stresses per se may not be required to develop doughs. This is consistent with a model for dough development that does not require extensive covalent bond rupture but instead involves mainly rupture and reformation of noncovalent interactions such as hydrophobic bonds and hydrogen bonds between protein chains.