Paper Number
BM6 

Session
Biological Macromolecules: Proteins, Cellulosic Biomass and other Biomaterials

Title
Redefining the role of the gluten network in the rheology of wheat dough

Presentation Date and Time
October 12, 2015 (Monday) 1:30

Track / Room
Track 4 / Constellation F

Authors (Click on name to view author profile)

1. Meerts, Mathieu (KU Leuven, Department of Chemical Engineering)
2. Cardinaels, Ruth (TU Eindhoven, Department of Mechanical Engineering)
3. Oosterlinck, Filip (DSM Ahead B.V., Materials Science Center)
4. Courtin, Christophe M. (KU Leuven, Laboratory of Food Chemistry and Biochemistry)
5. Moldenaers, Paula (KU Leuven, Department of Chemical Engineering)

Author and Affiliation Lines (in printed abstract book)
Mathieu Meerts¹, Ruth Cardinaels², Filip Oosterlinck³, Christophe M. Courtin⁴, and Paula Moldenaers^1
1Department of Chemical Engineering, KU Leuven, Leuven 3001, Belgium; ²Department of Mechanical Engineering, TU Eindhoven, Eindhoven 513, The Netherlands; ³Materials Science Center, DSM Ahead B.V., Geleen 6167, The Netherlands; ⁴Laboratory of Food Chemistry and Biochemistry, KU Leuven, Leuven 3001, Belgium

Speaker / Presenter 
Meerts, Mathieu

Text of Abstract
Although bread making has been practised for millennia, the fundamental understanding of the relations between dough microstructure and rheology is still surprisingly limited. It is well known that the dough matrix consists of a hydrated gluten network filled with starch granules. There is, however, no consensus yet about the specific contribution of each of these major constituents (gluten and starch) to the overall dough behavior. We have tackled this research question by investigating the rheological behavior of both components individually, and by studying mixtures of different gluten-to-starch ratios as well as dough made from weak and strong flours. Oscillatory and creep-recovery experiments are implemented to investigate respectively the linear and nonlinear viscoelastic behavior in shear. Uniaxial extensional tests are performed by means of an extensional viscosity fixture on a rotational rheometer. In the nonlinear region, dough behavior appears to be primarily determined by the response of the gluten network, which is in line with the findings of previous studies. Surprisingly, this conclusion does not seem to hold for the linear dough behavior, which is also strongly affected by the starch granules. As a result, only nonlinear rheological tests are able to distinguish strong from weak flour dough. The value of the strain hardening index (SHI) clearly reflects differences in both gluten quantity and quality, and is also affected by changes in water content and mixing time. To further elucidate the precise role of the gluten network in dough behavior, we have studied the effect of glucose oxidase on dough rheology. This enzyme is believed to modify the existing gluten network by creating additional disulfide crosslinks. Changes in the gluten network are again most apparent in nonlinear rheological tests, and with the SHI we are able to quantify the concentration-dependent strengthening effect of glucose oxidase on the gluten network.