Impact of sourdough and transglutaminase on gluten-free buckwheat bread quality

Abstract

Gluten-free (GF) bread based on starch has low sensory quality and stales faster than conventional wheat bread. At the same time, it is characterized by low nutritional value. Buckwheat flour can be used as an ingredient of GF bread improving favourably its nutritional properties. The application of transglutaminase (TG) that modifies proteins through cross-linking can further improve the overall quality of GF bread. In the present study, we investigated the effectiveness of TG used together with various doses of buckwheat sourdough, prepared using starter cultures L. plantarum ŁOCK 860 and L. brevis ŁOCK 1267, on the quality features of GF buckwheat bread. Compared to control, the exclusive addition of sourdough reduced significantly (p < 0.05) the specific volume of the bread, whereas the crumb was more cohesive and springy with a parallel TG addition. The crumb had lower density, similar to that of conventional bread. The flavor and aroma of the GF buckwheat bread were also improved noticeably. The use of sourdough had a significant effect on the mechanical properties of the crumb. Its structure became more springy. Moreover, the overall sensory quality of experimental bread increased, as the characteristic bitter aftertaste of buckwheat was less noticeable. In conclusion, the simultaneous use of buckwheat sourdough and TG had a positive effect on the total quality score which can lead to the increased sensory acceptability of the GF buckwheat bread.