Utjecaj različitih lioprotektora na preživljavanje funkcionalnih starter kultura tijekom liofilizacije

undergraduate thesis

• Title (english): The effect of various lyoprotectors on survival of functional starter cultures during the lyophilisaton
• Author: Irena Budimir
• Mentor: Jagoda Šušković (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Antibiotic, Enzyme, Probiotic and Starter Cultures Technology); Zagreb
• Defense date and country: 2012-06-29, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Liofilizacija ili sušenje proizvoda u zamrznutom obliku je postupak sušenja kojim se tekući dio materijala odvodi sublimacijom. U ovom radu je provedena liofilizacija potencijalnih probiotičkih sojeva Enterococcus faecium ZG1-54, Lactobacillus pentosus ZG2-25, Lactococcus lactis ZG5-9 i Lactococcus lactis ZG5-32 te je ispitan učinak obranog mlijeka i inulina na preživljavanje ovih bakterija tijekom navedenog procesa. Pri tome, fosfatni pufer je korišten kao kontrola, a broj stanica prije i nakon liofilizacije određivan je indirektnom metodom. Dobiveni rezultati ukazuju na to da lioprotektori imaju zaštitni učinak tijekom liofilizacije, s obzirom da njihov dodatak doprinosi povećanom preživljavanju ispitanih sojeva tijekom tog procesa. Dodatkom obranog mlijeka postignuta je manja smrtnost stanica u usporedbi s rezultatima dobivenim primjenom inulina te fofatnog pufera, što ga čini najboljim izborom u odabiru lioprotektora. Probiotički soj Lactococcus lactis ZG5-9 pokazuje najbolje preživljavanje tijekom liofilizacije uz dodatak obranog mlijeka, dok probiotički soj Lactococcus lactis ZG5-32 najuspješnije preživljava proces liofilizacije uz dodatak prebiotika inulina. Prema tome, liofilizacija se uz odabir učinkovitog lioprotektora može uspješno primijeniti za proizvodnju i čuvanje probiotičkih sojeva kroz dulje vrijeme jer omogućuje održavanje točno propisanog broja živih aktivnih probiotičkih bakterija kojeg je potrebno unijeti u organizam kako bi probiotici iskazali pozitivne učinke na zdravlje.

Abstract (english)

Lyophilisation, or desiccation of a frozen state product, is a drying method by which the liquid part of the material is being separated through sublimation. The lyophilisation in this work is carried out on the potential probiotic strains: Enterococcus faecium ZG1-54, Lactobacillus pentosus ZG2-25, Lactococcus lactis ZG5-9 and Lactococcus lactis ZG5-32 and, additionally, we tested the effect of skimmed milk and inulin on survival of these bacteria during the given process. In achieving that, a PBS - phosphate buffer solution was used as a controlling agent, and the number of cells before and after lyophilisation had been determined by an indirect method. The obtained results are indicating that lyoprotectors have a preserving effect during the lyophilisation, since their addition contributes to increased survival of tested strains during that process. By adding skimmed milk, a smaller mortality of cells was achieved than the one shown in results of inulin and phosphate buffer addition, which makes skimmed milk the best lyoprotector choice. The probiotic strain Lactococcus lactis ZG5-9 is showing the strongest resistance during the skimmed milk lyophilisation, whereas the probiotic strain Lactococcus lactis ZG5-32 has a maximal survival rate in the probiotic inulin lyophilisation.To conclude, by using a proper lyoprotector in lyophilisation we can efficiently improve industrial production and preserve probiotic strains through a longer period of time. Lyophilisation enables us to precisely maintain the prescribed number of probiotic bacteria which is needed in our nutrition in order to have a positive effect on our health.

• Keywords: bakterije mliječne kiseline; liofilizacija; lioprotektori; probiotici
• Keywords (english): freeze-drying; lactic acid bacteria; probiotics; lyoprotectans
• Language: croatian
• URN:NBN: urn:nbn:hr:159:495131
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-15 09:46:16