Optimiranje uvjeta proizvodnje kefirnog napitka u horizontalnom rotirajućem cijevnom bioreaktoru

master's thesis

• Title (english): The optimisation of process parameters in kefir drink production in horizontal rotating tubular bioreactor
• Author: Nives Jelačić
• Mentor: Mladen Pavlečić (mentor)
• Committee member: Antonija Trontel (predsjednik 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: 2021-12-01, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Kefirni napitak je fermentirani proizvod s blagotvornim učinkom na zdravlje. Dobiva se fermentacijom hranjive podloge u kojoj se nalazi šećer djelovanjem združene kulture mikroorganizama koja se sastoji od bakterija octene kiseline, bakterija mliječne kiseline te kvasaca. Zrnca korištena za ovaj rad su iz kućnog uzgoja i nije poznat točan mikrobiološki sastav. Preliminarnim istraživanjima u manjem mjerilu utvrđena je optimalna količina početne količine inokuluma od 10 % (m/V) koja je potom korištena za daljnja istraživanja u horizontalnom rotirajućem cijevnom bioreaktoru (HRCB-u). U ovom diplomskom radu također je ispitana mogućnost proizvodnje kefirnog napitka u ovoj vrsti bioreaktora pri čemu je ispitivan utjecaj procesnih parametara kao što su brzina okretanja (3, 5, 7 okr/min) te vrsta rotacije biorekatora (kontinuirana ili intervalna). Najbolji rezultati ostvareni su u slučaju kada je korištena intervalna rotacija s 3 minute rotacije pri čemu je brzina okretanja bioreaktora iznosila 7 okr/min. Ovim istraživanjem dokazana je mogućnost korištenja HRCB-a u biotehnološkoj proizvodnji kefirnog napitka.

Abstract (english)

Kefir drink is fermented product with a benefitial health effect. It is made by fermentation of nutrient medium which contains sugar by the action of a mixed culture of microorganisms consisting of acetic acid bacteria, lactic acid bacteria and yeasts. The grains used in this research are from domestic cultivation and the exact microbiological composition is unknown. By preliminary research in smaller scale the optimal initial inoculum of 10 % (m/V) was determined, and was then used for further reaearch in a horizontal rotating tubular bioreactor (HRTB). In this master thesis also the possibility of kefir drink production in this bioreactor type was examined, where the influence of process parameters such as rotation speed (3, 5, 7 rpm) and bioreactor rotation type (continuous or interval) was also examined. The best results were obtained when interval rotation with 3 minutes of rotation was used, where the rotation speed was set to 7 rpm. This research proved the possibility of using HRTB in the biotechnological kefir drink production.

• Keywords: kefirni napitak; HRCB; intervalna rotacija; konstantna rotacija
• Keywords (english): kefir drink; HRTC; interval rotation; continuous rotation
• Language: croatian
• URN:NBN: urn:nbn:hr:159:001498
• Study programme: Title: Biotechnology; specializations in: Biochemical Engineering; Course: Biochemical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo (diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-12-02 14:23:29