Gluten-free flour fermented with autochthonous starters for sourdough production: Effect of the fermentation process

Abstract

Refined rice flour and wholegrain quinoa and buckwheat flours were used to prepare gluten-free sourdoughs. Two autochthonous LAB strains were isolated, one from quinoa (Limosilactobacillus fermentum Q3) and the other from buckwheat (Lim. fermentum T5). Lactiplantibacillus plantarum ATCC8014 was used as a reference starter. Two fermentation processes were evaluated, a single-step process (30 °C, 24 h) named SD1, and a daily refreshment process (backslopping for 10 days) named SD2. Sourdoughs were freeze-dried prior to analyses. Pasting properties, pentosan and polyphenol contents, and antioxidant activity were analysed. Flour properties were significantly modified by fermentation. Polyphenol extractability increased during fermentation, which resulted in a higher antioxidant capacity, mainly through a reducing mechanism. Q3 and T5 strains produced the most remarkable modifications of flour properties. Differences were found between both fermentation processes, mainly as a result of the development of different microbiota. The single-step fermentation (SD1) showed to be a simple and appropriate method for improving flour properties.