Utjecaj ultrazvuka na inaktivaciju odabranih bakterija u čistoj kuluri

master's thesis

• Title (english): The effect of ultrasound on the inactivation of selected bacterium in a clean culture
• Author: Branka Markuš
• Mentor: Anet Režek Jambrak (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Food Processes Engineering); Zagreb
• Defense date and country: 2012, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom radu željelo se istražiti kako ultrazvuk visokog intenziteta (amplitude, temperature i vremena tretiranja) djeluje na bakterije Bacillus cereus 30, Salmonella spp. 3064 i Staphylococcus aureus 3048. Pripremljene modelne suspenzije mikroorganizma u čistoj kulturi tretirane su ultrazvukom nominalne snage 600 W, pri frekvenciji od 20 kHz ultazvučnom sondom promjera 7 i 12,7 mm. Korištene su tri amplitude (50, 75 i 100%) primjenom sondi od 7 i 12, 7 mm. Obrada ultrazvukom visokog intenziteta provodila se u trajanju od 3, 6 i 9 min pri temperaturi od 20, 40 i 60 °C. Rezultati su obrađeni statistički primjenom računalnog programa STATGRAPHICS Centurion, te metodom odzivne površine (Response Surface Methodology, RSM) i centralno kopozitnog plana pokusa (Central Composite Design, CCD) . Ispitivanjem utjecaja ultrazvuka visokog intenziteta primjenom sondi od 7 i 12, 7 mm na inktivaciju bakterija u čistoj kulturi utvrđeno je da najveći utjecaj ima kombinacija čimbenika i to temperature u ovisnosti o vremenu tretiranja. Tretman kombinacijom ultrazvuka visokog intenziteta i blago povišene temperature djelovalo je najviše na inaktivaciju bakterija.

Abstract (english)

The aim of this thesis was to examine the effect of high-intensity ultrasound, (amplitude, temperature and treatment time) on bacterium Bacillus cereus 30, Salmonella spp. 3064 and Staphylococcus aureus 3048 in a clean culture. The model suspensions of microorganisms in clean culture was treated with ultrasound nominal power of 600W ,ultrasonic treatment probe (20 kHz) with a diameter 7 and 12,7 mm. There are used three amplitudes (50, 75 and 100 %) using the 7 and 12,7 mm probes, different times of treatment (3, 6 and 9 min) and temperature varied (20 , 40 and 60 °C). The results were statistically processed with STATGRAPHICS Centurion computer program (StatPoint Technology, Inc) and Response Surface Methodology (RSM), as well as with Central Composite Design (CCD). The study of the effect of high-intensity ultrasound, using 7 and 12.7 mm probes, on the inactivation of the bacterium in question on a clean culture showed that the combined treatment had the most influence, depending on temperature and treatment time. The high-intensity ultrasound treatment, along with a slightly elevated temperature (termosonification) had the greatest effect on the inactivation of bacteria.

• Keywords: ultrazvuk visokog intenziteta; bakterije; inaktivacija; planiranje eksperimenta; metoda odzivne površine
• Keywords (english): high intensity ultrasound; bacterium; inactivation; response surface methodology; experimental design
• Language: croatian
• URN:NBN: urn:nbn:hr:159:647120
• Study programme: Title: Food Technology; specializations in: Nutrition; Course: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer nutricionizam (diplomirani inženjer prehrambene tehnologije; smjer nutricionizam)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-18 07:45:52