TECHNOLOGICAL ASPECTS OF PRODUCING FERMENTED BEVERAGES WITH ANTIOXIDANT PROPERTIES BASED ON GRAIN RAW MATERIALS

Abstract

The purpose of the research work was to develop technological aspects of producing fermented beverages with antioxidant properties based on grain raw materials. The objects of research were samples of beverages based on barley grain. Probiotic starter cultures produced by Propionix LLC were used for microbial fermentation of plant beverages: concentrated microbial mass of the Propionibacterium freudenreichiisubsp strain. Shermanii KM 186 and bacterial concentrate Bifidobacterium longum B379M. It was found that the most intensively active acidity decreased after 6–8 hours of fermentation and reached values of 4.38–4.60 after 10 hours. Moreover, propionic acid bacteria accumulate acidity most intensively, both with individual use and in synergy with bifidobacteria. During fermenting with a combined starter culture, the viscosity of beverages increased by 53.4 % relative to the viscosity of the unfermented barley beverages. The observed patterns are associated with the synergistic action of microorganisms towards the hydrolysis of structural polysaccharides and the synthesis of exopolysaccharides. The highest concentration of polyphenolic compounds was found in beverages fermented with Propionibacterium freudenreichii (1.26 mgGAE/ ml) and with a combination of Propionibacterium freudenreichii and Bifidobacterium longum (1.24 mg-GAE/ml). The antioxidant activity of barley beverages was in the range of 71.0–100.7 %. The regularity of the increase in DHPPI activity of beverages fermented with microorganisms by 20.4–41.8 % was revealed. It has been established that during the fermentation of plant beverages by microorganisms, an increase in the content of dry substances by 14.5–28.5 %, protein components – by 21.7–28.3 % is observed relative to the unfermented beverages. In a scientific study, the technological parameters of obtaining fermented beverages based on barley grain were substantiated. It has been established that fermentation of beverages with probiotic microorganisms has a positive effect on the formation of the structure and nutritional value of the product, effectively increases the antioxidant activity and the content of polyphenolic compounds.