Proizvodnja kefirnog napitka u bioreaktoru s čvrstim slojem

master's thesis

• Title (english): Production of water kefir drink in a fixed-bed bioreactor
• Author: Petra Nejedly
• Mentor: Mladen Pavlečić (mentor)
• Committee member: Mario Novak (predsjednik povjerenstva)
• Committee member: Andreja Leboš-Pavunc (član povjerenstva)
• Committee member: Blaženka Kos (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology); Zagreb
• Defense date and country: 2024-12-18, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Kefirni napitak je fermentirani proizvod s probiotičkim učinkom. Dobiva se fermentacijom vodene otopine šećera, s mogućnošću dodatka voća kao izvora faktora rasta za sve mikroorganizme prisutne u kefirnim zrncima. U preliminarnom dijelu ovog istraživanja ispitan je utjecaj različitog vremena trajanja ekstrakcije (30 min, 45 min i 60 min) suhih smokvi na sastav podloge za proizvodnju kefirnog napitka u staklenkama te je utvrđeno da je najveća koncentracija šećera u hranjivoj podlozi postignuta nakon 60 minuta ekstrakcije. Na temelju rezultata preliminarnog istraživanja u drugom dijelu ovog diplomskog rada korišteno je upravo to vrijeme ekstrakcije (60 minuta) za pripremu hranjive podloge za proizvodnju kefirnog napitka, u bioreaktoru s čvrstim slojem, kod tri različite brzine protoka podloge (7,2 mL min⁻¹, 28 mL min⁻¹ i 112 mL min⁻¹). Najbolji rezultati postignuti su uz protok od 112 mL min⁻¹ jer je u tom uzgoju postignut najbolji prijenos mase u sustavu te je postignuta veća koncentracija različitih produkata karakterističnih za kefirni napitak. Ovi rezultati ukazuju na potencijalnu mogućnost upotrebe ovog tipa bioreaktora za proizvodnju kefirnog napitka u većem mjerilu.

Abstract (english)

Water kefir drink is a probiotic drink. It is obtained by fermentation of an aqueous solution of sugar, with the possibility of adding fruit as a source of growth factors for microorganisms found in water kefir grains. In preliminary part of this research, the influence of different extraction times of dried figs for the preparation of a medium for production of water kefir drink was examined. The highest concentration of extracted substrate in the medium was achieved after 60 minutes. Identical medium was used in the second part of this research where the possibility of using a fixed-bed bioreactor was examined. Three experiments with different medium flow rates were conducted. Experiment conducted with the flow rate of 112 mL min⁻¹ showed best results because the best transport of the mass in the system has been achieved. Possibility of using fixed-bed bioreactor in the production of water kefir drink was proved.

• Keywords: kefirni napitak; zrnca kefirnog napitka; ekstrakt smokve; protok; bioreaktor s čvrstim slojem
• Keywords (english): water kefir; water kefir grains; fig extract; flow; fixed-bed bioreactor
• Language: croatian
• URN:NBN: urn:nbn:hr:159:729867
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-01-09 10:45:23