Improving the technology of gluten-free bread with quinoa flour

Abstract

The object of this study is the technology of bread baking based on liquid sourdough and gluten-free flour mixture. The problem with this technology is that gluten-free raw materials do not contain gluten proteins, which ensure the elasticity and firmness of the dough and increase the porosity of the bread. To improve the structural and mechanical properties of the dough, new types of flour were introduced into the recipe compared to the analog recipe: quinoa, buckwheat, and oat. The positive effect of quinoa on dough quality has been known for a long time but the limitation in its use is the bitter taste caused by the content of saponins. A method of removing saponins using ultrasound (40 kHz, τ=20 min) has been proposed, which made it possible to remove 60 % of saponins and completely remove the bitterness of grains. At the same time, the content of proteins remained unchanged while the content of phenols decreased by only 0.1 mg GAE/g. The addition of 18 % (to the mass of the flour mixture) of quinoa flour and the reduction of the starch content in the recipe had a positive effect on the organoleptic parameters of the bread quality. The acidity of dough (4.4–5.2 °Н) and bread (0.6 °Н) decreased compared to the control sample, but it was sufficient for a normal fermentation process. Bread with quinoa flour had increased moisture (more than 66 %), which can negatively affect its stability during storage. An increase in the proportion of quinoa flour in the recipe by 5 % contributed to an increase in the porosity of the crumb by 2.1 %. The proposed technology for making gluten-free bread with Quartet quinoa flour based on liquid sourdough can be industrially implemented as it makes it possible to obtain a product with desirable consumer properties. The total duration of dough ripening was reduced by 1–1.5 hours, compared to the steam method, which increases the economic efficiency of the proposed technology.