Određivanje teksturnih svojstava i matematičko modeliranje sušenja voća prethodno obrađenoga ultrazvukom visokoga intenziteta

doctoral thesis

• Title (english): Determination of textural properties and mathematical modeling of drying of fruits pretreated with the high intensity ultrasound
• Author: Sven Karlović
• Mentor: Damir Ježek (mentor)
• Committee member: Branko Tripalo (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; Zagreb
• Defense date and country: 2013-06-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology
• Universal decimal classification (UDC): 664 - Production and preservation of solid foodstuffs

Abstract

Nove netoplinske metode obrade namirnica sve se više koriste kao nadopuna ili zamjena standardnim metodama koje koristi prehrambena industrija. Ultrazvuk visokog intenziteta zbog svojeg djelovanja na staničnu strukturu pokazuje potencijal da se iskoristi kao metoda predobrade ili obrade namirnice prije sušenja. Glavni cilj sušenja je osušiti neki prehrambeni materijal do željenog udjela vlage, uz minimalne troškove vezane za proces. Skraćenje vremena sušenja je vrlo važan faktor koji utječe na mnoštvo drugih čimbenika kao što su utrošak energije, povećanje kapaciteta sušare,. smanjenje broja zaposlenih i dr. U radu je ispitan utjecaj raznih parametara ultrazvuka (amplituda, ciklus, vrijeme obrade, frekvencija, promjer sonde), debljine uzoraka i parametara sušenja (vrijeme sušenja, temperatura, sušenja, vrsta sušare) na mehanička svojstva (teksturu) i boju voća. Pokazalo se da je ultrazvuk visokog intenziteta metoda koja se vrlo učinkovito može iskoristiti u procesu sušenja, s obzirom da znatno skraćuje vrijeme sušenja, što dovodi do uštede u energiji. Na temelju dobivenih podataka izračunate su neuronske mreže, koje su uspoređene s klasičnim matematičkim modelima sušenja. Ustanovljeno je da su tako izvedene mreže znatno preciznije od trenutnih matematičkih modela, u širokom rasponu parametara. Time su se pokazale potencijalno znatno efikasnijim u kontroli procesa sušenja, kao i proračunu parametara sušenja.

Abstract (english)

New non-thermal technologies for processing of foodstuff is more and more used as replacement or supplement to standard thermal technologies used in food industry. High intensity ultrasound has impact on cellular matrix, and exhibits potential for use as pre-treatment method for drying of foodstuff. Main purpose of drying process is elimination of water from foodstuff, using minimal amount of time and energy. Shortening of process is very important, as it has influence on other economic parameters as energy costs, increase of drying capacity, etc. In this thesis various parameters of ultrasound (cycle, frequency, process time, probe diameter), thickness of fruit, and drying parameters (drying temperature, time, etc.) were investigated, and results were compared to mechanical properties (hardness, adhesiveness, elasticity), color and structure of fruit. Results show evidently shorter drying time when ultrasonic pre-treatment was used. Artificial neural networks (ANN) are calculated based on obtained data, and compared to traditional mathematical models for drying. ANN’s show more potential for use in process control and prediction of process parameters, as they can implement large number of variables, as opposed to mathematical models.

• Keywords: ultrazvuk visokog intenziteta; analiza teksture; matematičko modeliranje; umjetna neuronska mreža; voće
• Keywords (english): high intensity ultrasound; texture analysis; mathematical modelling; artificial neural network; fruit
• Language: croatian
• URN:NBN: urn:nbn:hr:159:081959
• Promotion: 2013-09-22
• Study programme: Title: Food Technology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti (doktor/doktorica znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2018-05-17 10:02:30