Influence of the microencapsulation on the functional properties of probiotic strains Lactobacillus helveticus M92, Lactobacillus plantarum L4 i Enterococcus faecium L3

Da bi izazvali željene pozitivne učinke na zdravlje, probiotički pripravci moraju sadržavati žive mikrobne stanice u koncentracijama višim od 106 po gramu proizvoda. Zbog toga se istražuju različite metode koje mogu doprinijeti povećanju njihovog preživljavanja tijekom biotehnološke proizvodnje, čuvanja ili primjene probiotika u različitim proizvodima, te nakon oralne primjene u gastrointestinalnom traktu domaćina. Cilj ovog rada je bio ispitati utjecaj različitih metoda mikroinkapsulacije na preživljavanje probiotičkih bakterija Lactobacillus helveticus M92, Lactobacillus plantarum L4 i Enterococcus faecium L3. Stoga je, provedena mikroinkapsulacija stanica vlažne biomase i liofiliziranih stanica, a zatim i liofilizacija mikroinkapsuliranih stanica svježe biomase L. helveticus M92, L. plantarum L4 i E. faecium L3, te je ispitan učinak mikroinkapsulacije na funkcionalna svojstva probiotičkih sojeva. Mikroinkapsulacija je provedena u alginatu i u karagenanu, te u kazeinu djelovanjem enzima transglutaminaze. Veći postotak preživljavanja mikroinkapsuliranih stanica L. helveticus M92, L. plantarum L4 i E. faecium L3, u simuliranim uvjetima gastrointestinalnog trakta, u odnosu na stanice koje nisu mikroinkapsulirane, ukazuje na zaštitnu ulogu mikroinkapsulacije za probiotičke sojeve. Broj živih stanica probiotičkih bakterija u svim uzorcima bio je veći od 106 CFU/g, što je u skladu sa zahtjevima koje moraju ispunjavati probiotički proizvodi.In order to express their health benefits, the probiotic preparations need to contain at least 106 viable cells per gram of the product. Therefore, several different methods have been investigated with the aim to improve the viability of probiotics during their biotechnological production, storage or application in different food products and after an oral application in the host gastrointestinal conditions. The aim of this thesis was to investigate the influence of different methods of microencapsulation on the survival of probiotic bacteria Lactobacillus helveticus M92, Lactobacillus plantarum L4 i Enterococcus faecium L3. Hence, the microencapsulation of free cells and freeze-dried bacterial cells of L. helveticus M92, L. plantarum L4 i E. faecium L3 was undertaken, also free cells were microencapsulated and afterwards freeze-dried, in order to investigate the effect of the microencapsulation on the functionality of probiotic strains. The microencapsulation of probiotics was performed in alginate, in κ-carrageenan and in transglutaminase-induced casein. The higher percentage of the survival of microencapsulated cells of L. helveticus M92, L. plantarum L4 i E. faecium L3 compared to the percentage of the survival of nonmicroencapsulated probiotic cells, in simulated gastrointestinal tract conditions, indicates the protective effect of the microencapsulation on the probiotic strains. The viable cell count of probiotic strains in all samples was above 106 CFU/g, what is in accordance with the claims set up for probiotic products