The effect of tempering on protein properties and arabinoxylan contents of intermediate wheatgrass (Thinopyrum intermedium) flour

Background and objectives: To benefit from ecosystem services provided by intermediate wheatgrass (IWG, Thinopyrum intermedium) cultivation, its processing conditions require optimization to facilitate its use in foods. This study assessed tempering as a strategy to improve IWG flour properties relevant for dough making. Findings: Tempered IWG samples had significantly higher maximum torque in the GlutoPeak, which strongly correlated with lower contents in total and water-extractable arabinoxylans (p <.05, r = −0.481; p <.01, r = −0.611) and phosphate buffer-soluble proteins (p <.01, r = −0.893). While higher maximum torque was observed when IWG was tempered to 14% (compared to 12%), target moisture and tempering time did not have any effect. Tempering induced significant reductions in accessible thiols, which also negatively correlated with maximum torque (p <.05, r = −0.473). SDS-PAGE analysis, however, did not indicate a shift in flour protein profiles. Conclusions: Tempering significantly increased maximum torque and significantly reduced the contents of phosphate buffer-soluble proteins, accessible thiols, and arabinoxylans. Together, these findings imply increased protein aggregation and an improved IWG protein network. Significance and novelty: This work demonstrates that the interaction between proteins and arabinoxylans is crucial for IWG dough properties and can be influenced by processing methods.