Bean is an ancient crop, that has due to its nutritional value a high potential in food industry, especially in bakery, as there is a growing interest for gluten-free products. Inclusion of bean flour in such products would contribute to larger contents of proteins, dietary fibres, minerals and other bioactive compounds, furthermore there would be a larger variety of gluten-free products. Despite the nutritional properties, the use of bean flour in food industry is limited by the presence of antinutritional factors, so there is a need of an effective method for degradation and reduction of antinutritional factors. The aim of the thesis was optimization of lactic acid fermentation of bean flour, which has been already shown as a good potential method for degradation of phytic acid. As starter cultures for lactic acid fermentation three Lactobacillus strains (L. plantarum, L. brevis in L. fermentum) were tested on two substrates – brown and white bean flour with different fermentation times (24, 48 and 72h). Lactic acid fermentation was evaluated by colonies forming units (CFU) count, pH measurement and determination of lactic acid concentration. Additionally, the assay of phytase activity in the solid medium and in a fermentation broth was performed. The optimal time of lactic acid fermentation considering biomass increment was 24 hours. Starter culture L. fermentum and white bean flour as a substrate proved to be the most useful combination with the highest phytase activity detected and the lowest lactic acid concentration, which was also confirmed by the higher pH and the lower CFU count.
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