Evaluation of common and durum wheat rheological quality through Mixolab® analysis after field damage by cereal bugs

The pre-harvest damage of wheat by sunn pests decreases flour quality. Mixolab® is a recent instrument that can be used to accurately describe the technological behaviour of flour dough, since it is able to evaluate both protein and starch components at the same time. Two-year field experiments were carried out to study the effect of Eurygaster maura (Heteroptera: Scutelleridae) feeding on the quality traits of common and durum wheat, recorded using different protocols, in comparison to the traditional sodium dodecyl sulphate sedimentation test (SSV). In 2012-13 growing season, a damage rate between 16% and 21% of damaged kernels led to a greater reduction in dough stability for common (-65%) than for durum wheat (-32%), while the protein strength was affected more by insect activity in durum wheat (-56%). In 2013-14 growing season, E. maura feeding (on average 32% of damaged kernels) reduced SSV by 5% and 66%, dough stability by 12% and 30%, and protein strength by 12% and 16%, for common and durum wheat, respectively. The increasing percentages of damaged kernels in both crops led to a clear decrease in dough stability and protein strength; a significant change in the rheological parameters was noticeable at a 2.5% level of damaged kernels. SSV resulted to be significantly correlated to Mixolab® dough stability, the protein strength, the protein network wakening rate (α) and Change in Mixolab Consistency (CMC, "Wheatbug" protocol) for both common and durum wheat. Therefore, Mixolab® can be considered a suitable tool for a quick detection of damage caused by sunn pests in common and durum wheat flour.