Gliadin and zein show similar and improved rheological behavior when mixed with high molecular weight glutenin

Small amplitude and lubricated squeezing flow tests were performed to investigate the effect of high molecular weight glutenin (HMWG) on the rheological properties of gliadin and zein dough composites. It was hypothesized that addition of small amounts of HMWG to zein cause changes in its viscoelastic properties in the same way as its addition to gliadin. Starch (87%, w/w) and protein/protein composites (13%, w/w), and water were mixed into dough. The water content of prepared dough was in the 41.7–45.3% range. Composites were gliadin-HMWG and zein-HMWG. Phase angle and complex modulus (G*) were obtained from frequency sweep tests at 0.5% strain amplitude over a 0.01–100 rad/s frequencies. Lubricated squeezing flow test were carried out at a range of strain rates to determine the sample extensional viscosities.Gliadin and zein samples exhibited high phase angle values that decreased with the addition of HMWG, which was attributed to enhancement of their elastic characteristics. A similar trend was observed in lubricated squeezing flow results. HMWG incorporation increased the extensional viscosities of gliadin and zein samples. This study suggests that rheological properties of zein can be improved with HMWG addition and provides basic information for future investigations on developments for gluten-free products.

► Dough model systems were prepared from starch and protein/protein composites. ► Effect of high molecular weight glutenin on gliadin and zein doughs was investigated. ► Improved rheological properties were observed with HMWG addition. ► Potential applications of other cereal prolamins in gluten free industry.