Izvedba matematičkog modela sušenja jabuke "Zlatni delišes" u infracrvenoj sušari uz predobradu ultrazvukom

master's thesis

• Title (english): Design of a mathematical model of drying apple "Golden delicious" in the infrared dryer at the pre-ultrasound
• Author: Ana Skupnjak
• Mentor: Mladen Brnčić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory of Thermodynamics); Zagreb
• Defense date and country: 2011-04-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Infracrveno sušenje uz predobradu ultrazvukom koristi niže temperature od uobičajenih metoda sušenja, koje se temelje na upotrebi toplinske energije uz veliki gubitak vode, održavajući boju, teksturu i strukturu. Svrha ovog rada je proučiti kako primjena ultrazvuka visokog intenziteta različitih amplituda djeluje na vrijeme sušenja uzoraka jabuka te na njihovu boju i teksturalna svojstva. Koristio se ultrazvučni ureĎaj maksimalne snage 200W i frekvencije 24 kHz. Amplitude rada iznose 0%, 20%, 40%, 60%, 80% i 100%. Optimiziranje procesa sušenja pomoću matematičkog modeliranja raspodjele temperature i vlage u materijalu može smanjiti potrošnju energije u infracrvenoj sušari. Dobiveni rezultati pokazuju da primjena ultrazvuka različitih amplituda skraćuje vrijeme sušenja i povećava difuzivnost vode, zbog tvorbe mikroskopski velikih kanalića na površini i unutar uzorka. Tvrdoća uzoraka postupno opada sa povećanjem intenziteta ultrazvuka, dok elastičnost raste sa porastom intenziteta ultrazvuka.

Abstract (english)

Infrared drying ultrasound pretreatment uses lower temperatures than conventional methods of drying, which are based on the use of thermal energy with a large water loss, keeping the colour, texture and structure. The aim of this work is to investigate the impact of high-intensity ultrasound of different amplitudes on drying the pieces of apple, as well on their colour and texture. Ultrasound device working at a frequency of 24 kHz with a power capacity about 200 W was used for ultrasound pretreatment. The amplitudes used are 0%, 20%, 40%, 60%, 80% i 100%. Optimizing the drying process using mathematical modelling of temperature and moisture distribution in the material can reduce energy consumption in a infrared dryer. The results show that the use of different amplitudes of ultrasound reduces the time of drying and increases water diffusivity due to the formation of microscopic channels in apple structure. Hardness of samples gradually drops with increase of intensity and duration of ultrasonic treatment, while elasticity of samples increases with high intensity.

• Keywords: jabuka; ultrazvuk visokog intenziteta; infracrveno sušenje; matematički model
• Keywords (english): apple; high intensity ultrasound; infrared drying; mathematical models
• Language: croatian
• URN:NBN: urn:nbn:hr:159:546921
• 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: Access restricted to students and staff of home institution
• Created on: 2017-05-30 11:38:30