Effects of selected lactobacilli on the functional properties and stability of gluten-free sourdough bread.

The aim of this investigation was to determine the influence of seven different spp. (Lb.) strains compared with a commercial starter culture (CS) on the functional properties of gluten-free (GF) sourdough-breads. The sourdough stability of selected strains was also evaluated upon back-slopping. Results showed that the bread properties were greatly affected by the Lb. strains. Millet breads achieved lower specific volumes (1.80-2.19 cm/g), higher crumb firmness (19.01-42.19 N) and lower relative elasticities (21.5-43.4%) than buckwheat breads. Compared with the CS, and positively influenced the crumb firmness of buckwheat and millet breads, respectively, while enhanced this property in both breads. Only one of the two strains was able to improve all functional properties in both GF breads. Back-slopping of the sourdoughs revealed stable properties in case of buckwheat, while maturity of the millet sourdough could not be reached. These observations were supported by the microbial count, metabolite production and carbohydrate consumption. Mature sourdough significantly improved the crumb firmness and porosity of the GF breads. These results highlighted the importance of selecting the appropriate lactic acid bacteria strains, to maximize the quality of GF bread.