| Abstract [eng] |
The objective of this study was to apply lactic acid bacteria such as Pediococcus acidilactici KTU05–7 and Pediococcus pentosaceus KTU05–9 from the KTU Department of Food Science and Technology collection for the production of fermented barley products and to test these products for bread baking. The chemical composition of barley as well as total and soluble β-glucan content in barley were determined, the influence of β-glucans on the viscosity of aqueous barley suspensions was evaluated. The changes of β-glucans and the activity of hydrolase class enzymes were measured in fermented barley products. The barley bread baking was done, when 20 % wheat flour was replaced by experimental barley flour, and bread quality was evaluated. The highest β-glucan content in comparison to other varieties was in Christopher (3,11 %) and Luokė (3,07 %) barley. The soluble β-glucan content of tested different barley varieties ranged from 0,43 to 1,49 %, the highest content was in Luokė and Noja DS barley. The barley products were suitable media for lactic acid bacteria growth and acid production. Fermentation with both P. acidilactici and P. pentosaceus resulted in decreased content of β-glucans and after 72 hours of fermentation only 5,5–25,5 % of β-glucans and 3,4–5,4 % of soluble β-glucans were remained not broken. Moderate linear correlations between the maximum viscosity (mPa) and total β-glucans as well as soluble β-glucans were determined (R = 0,55 and R = 0,68, respectively). α-Amylase, β-xylanase activities in fermented barley products decreased, protease and β-glucanase activity – increased. Addition of fermented barley product increased acidity, the specific volume and crumb porosity of bread, also increased hardness of bread crumb, reduced its elasticity and adhesion. The most accepted for customers was bread baked with P. pentosaceus fermented barley product. The degree of β-glucan hydrolysis in barley products prepared using P. pentosaceus and solid state fermentation was lower, so such fermented barley product could be used in bread baking, in order to retain the maximum amount of β-glucans and make bread acceptable to consumers. |
