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A New Method to Study Simple Shear Processing of Wheat Gluten-Starch Mixtures

¹Food Science and Technology Group, Faculty of Agriculture, University of Tabriz, Tabriz 51664, Iran. ²Food and Bioprocess Engineering Group, Department of Agrotechnology and Food Sciences, Wageningen University, Bomenweg 2, 6703 HD Wageningen 6700 EV, The Netherlands. ³Corresponding author. Fax: +31-317-482237. E-mail: AtzeJan.vanderGoot@wur.nl ⁴Department of Agrotechnology and Food Sciences, Centre for Protein Technology TNO-WUR, P.O. Box 8129, Wageningen 6700 EV, The Netherlands.

This article introduces a new method that uses a shearing device to study the effect of simple shear on the overall properties of pasta-like products made from commercial wheat gluten-starch (GS) blends. The shear-processed GS samples had a lower cooking loss (CL) and a higher swelling index (SI) than unprocessed materials, suggesting the presence of a gluten phase surrounding starch granules. Pictures of dough micro-structure by confocal scanning laser microscopy (CSLM) showed the distribution of proteins in the shear-processed samples. This study revealed that simple shear processing could result in a product with relevant cooking properties as compared with those of commercial pasta. Increasing gluten content in GS mixtures led to a decrease in CL and an increase in maximum cutting stress of processed samples, whereas no clear correlation was found for SI values of sheared products. It was concluded that the new shearing device is unique in its capability to study the effect of pure shear deformation on dough development and properties at mechanical energy and shear stress levels relevant to industrial processing techniques like pasta extrusion.