Određivanje termodinamičkih parametara pri procesiranju ultrazvukom visoke snage

master's thesis

• Title (english): Determination of thermodynamic parameters in the processing of high power ultrasound
• Author: Ivana Bošnjak
• 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: 2016-07-05, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Primjena ultrazvuka visokog intenziteta smatra se novom ne-termalnom metodom obrade hrane, pri čemu je samo trajanje tretiranja vrlo kratko i provodi se pri sobnoj temperaturi te na taj način dolazi do minimalnog procesiranja hrane i očuvanja njezinih karakteristika. Cilj ovoga rada je utvrditi optimalne termodinamičke parametre obrade pri kojima će se dobiti zadovoljavajući rezultati obrade, sa smanjenom potrošnjom energije u kraćem vremenu obrade. Ispitivanja su vršena na tri različita uzorka voda, sok jabuka i mlijeko, korištene su ultrazvučne sonde promjera 12,7 i 19,1 mm pri amplitudama 1%, 10%, 50%, 75% i 100%, u trajanju od 3,6 i 9 minuta (9 minuta samo za amplitudu 75%). Određivana je promjena temperature pri različitoj amplitudi i vremenu tretiranja za sva tri uzorka, određivan je koeficijent elektroakustičkog iskorištenja, mjerenje raspodjele tlaka i isijane akustične snage, te promjena reoloških parametara prilikom ultrazvučnog tretiranja. Rezultati istraživanja su pokazali da su uspješno karakterizirani termodinamički parametri ultrazvučnog tretiranja, te da su optimirani parametri ultrazvučne obrade za uzorke mlijeka, soka od jabuke i vode. Reološkim parametrima utvrđeno je da tretiranje ultrazvukom uzrokuje neznatne promjene na ispitivanim uzorcima.

Abstract (english)

The application of high power ultrasound is considered as a new non-thermal method of food processing, whereasduration of treatment is very short and it is conduct under room temperature, thus there isminimal food processing and preservation of all its characteristics. The aim of this study was to determine the optimum thermodynamic parameters that will get satisfactory results of treatment, with reduced power consumption in the shorter processing time. The examination were conducted with three different samples water, apple juice and milk. Where were used ultrasound probes that have diameters 12,7 and 19,1mm with amplitude 1%, 10%, 50%, 75% and 100%, for a time period of 3,6 and 9 minutes (9 minutes only for 75% amplitude). Change in temperature were determining for a different amplitudes and different times of treatment for all three samples. Investigated electroacoustic efficiency factor, measuring distribution of pressure, and radiation of acoustic power, statistical data processing and determination of changes in rheological parameters during ultrasonic treatment. The results showed that ultrasound treatment causes slight changes in the analysed samples.

• Keywords: ultrazvuk visoke snage; termodinamički parametri; voda; sok jabuka; mlijeko
• Keywords (english): high power ultrasound; thermodynamics parameters; water; apple juice; milk
• Language: croatian
• URN:NBN: urn:nbn:hr:159:871107
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-06-12 06:47:23