Proizvodnja fermentiranih probiotičkih napitaka s bioaktivnim peptidima primjenom soja Lactococcus lactis ZGBP5-51

master's thesis

• Title (english): Production of fermented probiotic drinks with bioactive peptides using strain Lactococcus lactis ZGBP5-51
• Author: Lucija Vuletić-Antić
• Mentor: Blaženka Kos (mentor)
• Mentor: Katarina Butorac (pomoć pri izradi, neposredni voditelj)
• Committee member: Andreja Leboš-Pavunc (predsjednik povjerenstva)
• Committee member: Ksenija Markov (član povjerenstva)
• Committee member: Rajka Božanić (član povjerenstva)
• 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: 2023-10-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Cilj ovog diplomskog rada bio je proizvesti funkcionalne fermentirane probiotičke napitke s bioaktivnim peptidima primjenom autohtonog potencijalnog probiotičkog soja Lactocococcus lactis ZGBP5-51, izoliranog, identificiranog i okarakteriziranog kao producenta proteolitičkih enzima. Proizvedena su tri fermentirana mliječna napitka od kojih je jedan sadržavao samo komercijalnu mezofilnu starter kulturu, drugi je sadržavao komercijalnu starter kulturu i soj L. lactis ZGBP5-51 u jednakim omjerima, a treći isključivo soj L. lactis ZGBP5-51. Optimizacijom uvjeta proizvodnje probiotičkih napitaka odabrana je mezofilna temperatura (28 °C) za provođenje fermentacije. Tijekom skladištenja u trajanju od 21 dan određen je broj živih bakterijskih stanica, pH vrijednost, stupanj kiselosti, odnosno volumni udio proizvedene mliječne kiseline, kao i mikrobiološka ispravnost. Najbolji rezultati postignuti su s napitkom proizvedenim primjenom komercijalne starter kulture i soja L. lactis ZGBP5-51 jer je izmjeren najveći broj živih bakterijskih stanica i najviša pH vrijednost tijekom skladištenja. Utvrđeno je preživljavanje soja L. lactis ZGBP5-51 tijekom procesa liofilizacije veće od 6 log CFU mL-1 što zadovoljava tehnološki kriterij izbora probiotičkih sojeva. Senzorskom analizom proizvedenih napitaka najveći prosječni broj bodova ostvario je napitak proizveden primjenom komercijalne starter kulture.

Abstract (english)

The aim of this thesis was to produce functional fermented probiotic drinks with bioactive peptides using the autochthonous potential probiotic strain Lactocococcus lactis ZGBP5-51, isolated, identified and characterized as a producer of proteolytic enzymes. Three fermented dairy beverages were produced, one containing only the commercial mesophilic starter culture, the second containing the commercial starter culture and the L. lactis ZGBP5-51 strain in equal proportions, and the third exclusively the L. lactis ZGBP5-51 strain. By optimizing the conditions for the production of probiotic drinks, a mesophilic temperature (28 °C) was chosen for fermentation. During storage for 21 days, the number of viable bacterial cells, pH value, degree of acidity, i.e. the percentage of lactic acid produced, as well as microbiological safety were determined. The best results were achieved with the beverage produced using the commercial starter culture and strain L. lactis ZGBP5-51, as the highest number of viable bacterial cells and the highest pH value were measured during storage. The survival of the strain L. lactis ZGBP5-51 during the lyophilization process was determined to be higher than 6 log CFU mL1 , which is in accordance with the technological criteria for the selection of probiotic strains. Sensory analysis of the produced beverages showed the highest average number of points by the beverage produced using a commercial starter culture.

• Keywords: probiotički napitci; bioaktivni peptidi; Lactococcus lactis
• Keywords (english): probiotic drinks; bioactive peptides; Lactococcus lactis
• Language: croatian
• URN:NBN: urn:nbn:hr:159:816283
• Study programme: Title: Molecular Biotechnology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka molekularne biotehnologije (magistar/magistra inženjer/inženjerka molekularne biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-06-27 13:30:53