Study of Exopolysaccharide Production by Lactic Acid Bacteria used in the Baking Industry and Comparison of Methods for Their Determination

Introduction: Exopolysaccharides are high molecular weight compounds consisting of monosaccharide residues and their derivatives, which have biological activity and play a protective role in physiological processes. The search for strains of lactic acid bacteria producing exopolysaccharides is a promising area of research due to their proven positive effect on the rheological properties of fermented food products, as well as human health. Purpose: To study the ability of lactic acid bacteria strains from the collection of FGANU NIIHP to produce exopolysaccharides, as well as to compare different methods of their determination - gravimetric, phenol-sulfuric acid Dubois method, anthrone reagent method and titrimetric Bertrand method. Materials and Methods: To determine the ability to produce exopolysaccharides, cultures of lactic acid bacteria were cultured on 12% malt mash for 48 hours at the optimum temperature for each strain. After protein removal and dialysis, the amount of exopolysaccharides was determined in the culture fluid by different methods. Results: It was found that all the collection strains formed exopolysaccharides in different amounts. The strains producing the highest amount of exopolysaccharides were identified as L.amilolyticus-2, L. plantarumA-63(d), L.amilolyticus-1, L.brevis-78(d), L. paracasei-6. The yield of the product containing exopolysaccharides produced by lactic acid bacteria ranged from 7 to 14.4 mg in 1 ml of culture liquid. The results of the study allowed us to conclude the correctness of Dubois method for estimating the content with respect to exopolysaccharides produced by lactic acid bacteria. Conclusion: The conducted studies confirm the ability of strains of lactic acid bacteria, from the collection of FGANU NIIHP, to produce exopolysaccharides. The correctness of the Dubois method for the determination of exopolysaccharides produced by lactic acid bacteria was established.