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The microbial diversity and pasting properties of three sourdoughs produced from composite gluten-free flours were investigated using 16S rRNA gene clone libraries and the Rapid Viscoanalyser. Finger millet-pearl millet (FP), Pearl millet-sorghum (PS) and Finger millet-sorghum (FS) sourdoughs were produced. Eleven aerobic bacteria and twelve lactic acid bacteria (LAB) were randomly selected from the sourdoughs. Presumptive Bacillus subtilis and Pediococcus spp. were identified in all the sourdoughs after 48 h of fermentation, while yeast was not detected in any of the products. The LAB population and pH ranged from log 7.70 CFU g −1 to log 10.52 CFU g −1 and 3.8 to 4.2 respectively. The findings showed that well-developed sourdough could be produced from these composite flours by spontaneous fermentation. Significant differences were observed in the pasting properties of all the sourdoughs. Decline in the tendency to retrograde occurred in all sourdoughs, thereby justifying the lower staling rate of final products. This study enhanced the corpus of existing knowledge on the microbial diversity of gluten-free sourdough and provided a basis for the possible application of Pediococcus spp. and Weisella spp. as a starter culture(s) in fermented products. [ABSTRACT FROM AUTHOR]

Indigenous grains for food production have the potential to combat food insecurity and poverty in Africa. The aim of the study was to determine the effect of sourdough fermentation on the acidity, microbiological quality, microbial diversity and rheological properties of three underutilized African cereals. The sourdoughs had pH ranging from 3.9 to 4.1. Finger millet and pearl millet sourdoughs had LAB counts >7 log cfu g−1 indicating they are suitable for use as starter culture(s). Microbial diversity was determined using culture dependent techniques and the identity of isolates was established using 16S rRNA gene sequencing. This showed the presence of Bacillus , Brevibacillus , Acinetobacter and Pediococcus species in the sourdoughs. An occurrence of Candida glabrata was observed in finger millet sourdough. Sourdough fermentation resulted in significant increases (p < 0.05) in the peak, trough and final viscosity of pearl millet and sorghum. A lower setback in the three samples indicated improved shelf-life. Starter culture(s) were identified that might be used in the production of gluten-free baked foods as a result of sourdough fermentation. [ABSTRACT FROM AUTHOR]