Utjecaj ultrazvuka visoke snage na bakterije mliječnog vrenja i senzorsku kvalitetu vina

master's thesis

• Title (english): Effect of high iontensity ultrasound on lactic acid bacteria and sensory quality of wine
• Author: Petra Čagalj
• Mentor: Leo Gracin (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); Zagreb
• Defense date and country: 2010-06-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Potencijalna upotreba ultrazvučnih valova za kontrolu mikroorganizama u vinu je neistražena. To onemogućava određivanje mogućnosti primjene ultrazvuka visokog intenziteta u tehnologiji vina. Bakterije mliječnog vrenja (BMV) su prisutne u svim moštovima i vinima, a odgovorne su za provođenje jabučno mliječne fermentacije. Osim toga pod određenim uvjetima mogu također uzrokovati nepoželjne promjene u aromi vina koje vino čine nepitkim, stoga je bitno provoditi jabučno mliječnu fermentaciju u kontroliranim uvjetima. Ovim radom želi se istražiti kako ultrazvuk visoke snage pri frekvenciji 24 kHz ultrazvučnom sondom nominalne snage 400 W utječe na bakterije mliječnog vrenja i senzorsku kvalitetu vina. Pripremljeni uzorci vina tretirani su protočnim ultrazvukom. Fourier-ovom transformacijom infracrvene spektroskopije (FTIR) određivali su se parametri vina. Nacjepljivanjem uzoraka vina na selektivne podloge dokazano je da su BMV prisutni u vinu. Rezultatima ispitivanja utvrđeno je da povišenja temperatura i produljeno djelovanje ultrazvuka imaju negativan utjecaj na aromu vina. Utvrđeno je da se rezistentnost bakterija mliječnog vrenja u vinu, smanjuje povećanjem temperature i produljenjem vremena tretmana ultrazvukom nominalne snage 400 W i frekvencije 24 kHz.

Abstract (english)

Potential use of ultrasonic waves to control microorganisms in wine is unknown. This prevents the possibility of determining the application of high intensity ultrasound in the wine technology. The lactic acid bacteria (LAB) are present in all musts and wine, and are responsible for conducting malolactic fermentation. Furthermore, under certain conditions they may also cause undesirable changes in the flavor of wine make wine undrinkable, so it is important to conduct malolactic fermentation under controlled conditions. The aim of this thesis was to examine how high intensity ultrasound at a frequency 24 kHz with a ultrasound probe with a nominal power of 400 W effects lactic acid bacteria and sensory quality of wine. Prepared samples of wine were treated with flow ultrasound. With the Fourier-transform infrared spectroscopy (FTIR) the parameters of the wine were determined. Inoculation of samples of wine on selective media showed that the LAB were present in wine. It was determined that higher temperatures and prolonged action of ultrasound have a negative impact on wine aroma. It was determined that the resistance of wine lactic alid bacteria, decreases with increase of temperature and prolonged time of treatment with ultrasound nominal power of 400 W and frequency 24 kHz.

• Keywords: ultrazvuk visoke snage; bakterije mliječnog vrenja; senzorska kvaliteta; vino
• Keywords (english): high intensity ultrasound; lactic acid bacteria; sensory quality; wine
• Language: croatian
• URN:NBN: urn:nbn:hr:159:368722
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-08-28 12:55:59