Isolation and characterization of lactic acid bacteria and yeasts from fermented sorghum flour

Sorghum (Sorghum vulgare Pers.) is a crop of great interest due to its high yield, its tolerance of adverse agronomic conditions that are becoming more and more frequent for the climate change, and its nutritional quality. In particular, the peculiar organization of the macronutrients (starch and proteins) of this cereal has led to the development of rudimental technologies to exploit its high value in the countries where its use is widely spread for the production of both food and beverages. Nevertheless, in Italy, it is primarily intended for zootechnical use and its application in human nutrition is still limited by cultural constrains. One of the most interesting characteristics of sorghum is the lack of gluten, which makes this cereal an eligible ingredient for coeliac people food. On the other hand, the lack of gluten limits the application of sorghum flour in the bakery industry. For this reason, after spontaneous fermentation of sorghum flour, we isolated and characterized lactic acid bacteria presenting useful characteristics able to improve the technological handling of this ingredient, in order to make sorghum flour usable for bakery products. Moreover, we have evaluated the pH and the Titratable Acidity (TTA) throughout the fermentation process. Regarding the sorghum flour microbiota, we have identified different strains of Weissella spp for the bacterial part, together with Pichia spp and Hanseniaspora spp for the yeast counterpart.