Effect of dough conditioners and refinement on intermediate wheatgrass (Thinopyrum intermedium) bread

Efforts are underway to establish the perennial grain intermediate wheatgrass (IWG, Thinopyrum intermedium) as food ingredient due to environmental benefits provided by its cultivation. IWG contains more protein than wheat but exhibits poor gluten-forming ability. This study evaluated if refinement or dough conditioners (wheat protein isolate, vital wheat gluten, ascorbic acid, a commercial enzyme blend, and transglutaminase) could compensate for this characteristic. Dough stickiness and physical attributes of breads made with IWG from two growing locations that was either completely, partly or un-refined were measured. In completely or partially refined breads from one location, transglutaminase reduced stickiness (from 0.721 ± 0.022 and 0.494 ± 0.012 to 0.602 ± 0.007 and 0.309 ± 0.006 N, respectively). However, in unrefined breads it resulted in unacceptably dense crumb, decreasing cell counts from 237 ± 16 to 93 ± 22 and 311 ± 28 to 86 ± 7 per area viewed, depending on growing location. In contrast, ascorbic acid improved crumb structure in completely refined breads, decreasing cell counts (from 247 ± 3 to 129 ± 6 and 356 ± 23 to 104 ± 4 per area viewed, depending on growing location) while increasing average cell size. Moreover, surfaces of breads made with ascorbic acid were smooth, while absence or use of other conditioners resulted in uneven, unappealing appearance. These results highlight how processing can improve IWG functionality.