In this master’s thesis, we investigated the effect of different encapsulation formulations on the survival, growth, and metabolic activity of Lactobacillus paragasseri K7. The aim of the study was to compare encapsulated bacteria with free cells and to evaluate the influence of alginate and cyclodextrin (CD) derivatives (CD-citrate and CD-maleate at concentrations of 0,1 % and 0,2 %) on cell protection during simulated in vitro digestion, as well as on bacterial growth and bacteriocin activity (BA). The microbeads were prepared using the ionic gelation method. After exposure to simulated gastric and intestinal phases, bacterial survival was determined, while growth, changes in pH values, optical density, and BA were monitored during incubation. The results showed that encapsulation under the applied in vitro digestion conditions did not provide better protection compared to free cells. Differences among encapsulated samples were observed depending on the composition of the carrier material, with some formulations exhibiting greater mechanical instability and consequently increased cell release. Encapsulated bacteria showed slower growth, a smaller decrease in pH values, and lower optical density values compared to free cells. BA was detected in free cells, whereas it was detected only exceptionally in encapsulated samples. The results confirm that the effectiveness of encapsulation strongly depends on the composition and stability of the carrier material and requires further optimization.
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