| Abstract [eng] |
The aim of this project was to evaluate the potential use of lactic acid bacteria (LAB) in fermentation of sourdough for gluten-free bread production. The quality of bread, in terms of enhanced texture, prolonged shelf life, improved organoleptic and nutritional profile, can be strongly influenced by the addition of sourdough. This is especially relevant for gluten-free bread, which demand is increasing constantly. The use of sourdough represents an attractive alternative to increase the quality of gluten-free bread. The use of hemp, chia, quinoa seeds as well as maize and rice flours fermented with selected LAB for gluten-free bread production was investigated. The evaluation of antimicrobial activities of LAB against the most common spoiling fungi isolated from grain products belongs to Bacillus subtilis subsp. spizizenii, Aspergillus niger, Fusarium, and Penicillium, were performed using an agar well diffusion assay method. Based on antimicrobial and phytase activity results from 13 LAB strains belonging to Leuconostoc and Lactobacillus genus was chosen 3: Lactobacillus curvatus 51, Lactobacillus farraginis 206 and Lactobacillus sanfranciscensis W2. Six sourdoughs from maize and rice flours fermented with LAB were prepared. pH, total titratable acidity, volatile acidity, D-, L-lactic acid, quantity of LAB and yeast, amylase, xylanase, phytase, protease activity of sourdoughs fermented by LAB were investigated. Results showed that flour and bacteria strain had a significant influence on sourdough quality. Fermented products of various valuable seeds (chia, hemp, quinoa) were produced. pH, total titratable acidity, phytase activity were determined. Fermentation time, seed and bacteria strain have a significant influence on fermented product pH, total titratable acidity values and content of LAB. The highest phytase activity was found of seeds products fermented with L. sanfranciscensis W2. Gluten-free bread with sourdoughs, valuable quinoa, chia, hemp seeds, and their fermented products were produced. Bread quality, organoleptic properties, and acceptability were evaluated. Results showed that LAB strain and the addition of sourdough ratio had a significant influence on gluten-free bread quality and acceptability. Fermented seeds products decreased pH, specific volume of gluten-free bread. The addition of fermented products increased the acceptability of gluten-free bread. The most acceptable bread was produced with fermented chia and quinoa products. |
