Sustainable Processes and Physico-Chemical Characterization of Artisanal Spontaneous Gluten Free Sourdough (Quinoa, Amaranth and Brown Rice) Compared to Wheat Sourdough

The industry predominantly depends on synthetic or artificial additives, occasionally permitting the inclusion of natural molecules sourced from plants or replicated from their original counterparts. The production of bakery products increasingly uses sourdough to improve the quality of bread or to obtain “clean label” products (free of artificial additives). The additive production sector contributes to this concern through the synthesis of potentially harmful compounds, the utilization of hazardous chemicals and solvents, the management of resulting by-products, and reliance on non-renewable resources for manufacturing. One percent of the world’s population suffers from celiac disease. Celiac disease is treated by excluding gluten from the diet. Most gluten-free bakery products have low nutritional and sensory quality. Therefore, sourdough is being used to replace chemical yeast to improve the sensory and nutritional quality and increase the shelf life of gluten-free bakery products. Three gluten-free sourdoughs were prepared with different flours: brown rice, quinoa and amaranth, in order to compare them with traditional sourdough (wheat) and optimize the most suitable temperature for the conservation of sourdoughs. Physicochemical analysis (pH, titratable acidity and color), antioxidant activity (FRAP, ORAC and ABTS), total phenolic compound content (Folin–Ciocalteu), total aflatoxin content, lactic and acetic acid content and microbiological analysis (mold and yeast content and bacterial and fungal composition (microbiota composition)) were carried out during the elaboration process and at different storage temperatures. A higher microbiological quantity of molds and yeasts (7.97 log CFU/mL), non- Saccharomyces yeasts (7.78 log CFU/mL) and lactic acid bacteria (8.10 log CFU/mL) and fungal composition were observed in the amaranth sourdough. The wheat sourdough obtained a higher total content of phenolic compounds (33.03 mg GAE g −1 ) and antioxidant capacity in ABTS and FRAP, but the quinoa sourdough had the highest ORAC content. In addition, it was observed that the adequate temperature for the conservation of the doughs is 25 °C, due to the predominance of Lactobacillus spp. and Pediococcus spp. bacteria in the sourdough. Therefore, pseudocereal sourdoughs (quinoa and amaranth) could be an alternative to incorporate into the preparation of gluten-free bread, since their microbial composition, physicochemical composition, antioxidant activity and total phenolic compounds would contribute to gluten-free bread and thus produce health benefits for people with celiac disease.