Background. Gluten-free bread is nowadays a very important type of grain products. The growing knowledge of raw materials for its production allows also to improve technological quality and ensures this bread has characteristics of health-promoting food. The aim of the work was to develop a production technology and assess the quality of gluten-free (buckwheat) sourdough bread having the following variants: with half or all of the added water being replaced with fermented beetroot (Beta vulgaris L.) puree. The research included the determination of the total acidity of the first sourdough phase, the measurements of the dough fermentation process by means of a fermentograph and the physicochemical evaluation of the produced loaves of bread. Antioxidant properties of the finished products were also determined, broken down into bread crumb and crust.
Results and conclusion. The analyzes conducted clearly indicated that replacing water with fermented beetroot puree had a positive effect on the fermentation of buckwheat dough, its overall  quality and was characterized by higher antioxidant activity compared to the control sample. It was also proven that extending the fermentation of the liquid sourdough to four days had a positive  effect on the quality of the final product.