| Abstract [eng] |
This study is dedicated to the extraction of dietary fiber-enriched flaxseed press cake fractions, selection of biotechnological tools for their processing and application to produce functional foods. In the initial stage of the experiment, dry fractionation was used for flaxseeds to produce dietary fiber-enriched products with an average total dietary fiber content of 26 %. The increased dietary fiber content in fractions also increased water absorption. Ultrasonication of dietary fiber-enriched flaxseed fraction fractions (850 kHz; 0.9 W/cm2, 1.3 W/cm2, 2.0 W/cm2) had a significant effect on flaxseed dietary fiber. In flaxseed fractions with higher dietary fiber content, higher microbial contamination was detected than in smaller particle size fractions with less dietary fiber content. Applying low frequency (37 kHz) ultrasonic flaxseed dietary fiber processing in 15 min. at low temperatures (30–50 °C), a significant reduction in microbial contamination was observed. In addition, the use of dietary fiber-enriched flaxseed fractions in fermentation processes and preparation of hydrated gels was investigated. Ultrasonication of flaxseed press cake (850 kHz; 0.9 W/cm2, 1.3 W/cm2, 2.0 W/cm2) before solid-state fermentation had a significant positive effect on the reproduction of lactic acid bacteria and on the formation of lactic acid D(–) and L(+) isomers. Ultrasonication of aqueous suspensions increased gel viscosity by an average of 33.18 %. The best quality of the gels was obtained by using 40 % of flaxseed press cake and 60 % of blackcurrant press cake. Ultrasonication increased the viscosity of flaxseed dietary fiber more than their mixtures with blackcurrant press cake. Thus, ultrasonication makes it possible to intensify the process of gel formation and increase the efficiency of this type of production process. |
