Effect of extrusion on the polymerization of wheat glutenin and changes in the gluten network

The changes in the gluten network during extrusion treatment were studied by assessing the polymerization behavior of glutenin. Gluten samples were extruded at different barrel temperatures, screw speeds, and flow rates. The results indicated that high molecular weight glutenin subunits increased while free sulfhydryl groups and low molecular weight glutenin subunits decreased as the screw speeds and flow rates increased during extrusion treatment. Specific β-sheet structures of gluten clearly increased, while α-helices and β-turns fluctuated during extrusion processing, thus forming a tight gluten network. The characteristics of the protein network were evaluated by confocal laser scanning microscopy. The results showed that a homogeneous and denser gluten network was formed at higher extrusion temperatures during the extrusion process, which may be related to the polymerization of low-molecular-weight glutenin subunits. This study provides a theoretical basis for the improvement and regulation of extrusion quality during the gluten extrusion process.